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diff --git a/bin/ksh/ksh.1 b/bin/ksh/ksh.1 index e569ce3aced..e63589a6d0d 100644 --- a/bin/ksh/ksh.1 +++ b/bin/ksh/ksh.1 @@ -1,3328 +1,4595 @@ -'\" t -.\" $OpenBSD: ksh.1,v 1.14 1999/03/01 06:05:35 aaron Exp $ -.\"{{{}}} -.\"{{{ Notes about man page -.\" - use the pseudo-macros .sh( and .sh) to begin and end sh-specific -.\" text and .ksh( and .ksh) for ksh specific text. -.\" - put i.e., e.g. and etc. in italics -.\"}}} -.\"{{{ To do -.\" todo: Things not covered that should be: -.\" - distinguish (POSIX) special built-in's, (POSIX) regular built-in's, -.\" and sh/ksh weirdo built-in's (put S,R,X superscripts after command -.\" name in built-in commands section?) -.\" - need to be consistent about notation for `See section-name', ` -.\" See description of foobar command', `See section section-name', etc. -.\" - need to use the term `external command' meaning `a command that is -.\" executed using execve(2)' (as opposed to a built-in command or -.\" function) for more clear description. -.\"}}} -.\"{{{ Title -.TH KSH 1 "August 19, 1996" "" "User commands" -.\"}}} -.\"{{{ Name -.SH NAME -ksh \- Public domain Korn shell -.\"}}} -.\"{{{ Synopsis -.SH SYNOPSIS -.ad l -\fBksh\fP -[\fB\(+-abCefhikmnprsuvxX\fP] [\fB\(+-o\fP \fIoption\fP] [ [ \fB\-c\fP \fIcommand-string\fP [\fIcommand-name\fP] | \fB\-s\fP | \fIfile\fP ] [\fIargument\fP ...] ] -.ad b -.\"}}} -.\"{{{ Description -.SH DESCRIPTION -\fBksh\fP is a command interpreter that is intended for both -interactive and shell script use. Its command language is a superset -of the \fIsh\fP(1) shell language. -.\"{{{ Shell Startup -.SS "Shell Startup" +.\" $OpenBSD: ksh.1,v 1.15 1999/03/02 23:46:53 aaron Exp $ +.\" +.\" Copyright (c) 1980, 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)ksh.1tbl 8.2 (Berkeley) 8/19/96 +.\" +.Dd August 19, 1996 +.Dt KSH 1 +.Os BSD 4 +.Sh NAME +.Nm ksh +.Nd public domain Korn shell +.Sh SYNOPSIS +.Nm ksh +.Op Fl +abCefhikmnprsuvxX +.Op Fl +o Ar option +.Oo [ Fl c Ar command-string [ +.Xo Ar command-name ] No \&| Fl s No \&| +.Ar file No ]\ +.Xc +.Op Ar argument ... Oc +.Sh DESCRIPTION +.Nm ksh +is a command interpreter intended for both interactive and shell +script use. Its command language is a superset of the +.Xr sh 1 +shell language. +.Ss Shell startup The following options can be specified only on the command line: -.IP "\fB\-c\fP \fIcommand-string\fP" -the shell executes the command(s) contained in \fIcommand-string\fP -.IP \fB\-i\fP -interactive mode \(em see below -.IP \fB\-l\fP -login shell \(em see below -interactive mode \(em see below -.IP \fB\-s\fP -the shell reads commands from standard input; all non-option arguments -are positional parameters -.IP \fB\-r\fP -restricted mode \(em see below -.PP -In addition to the above, the options described in the \fBset\fP built-in -command can also be used on the command line. -.PP -If neither the \fB\-c\fP nor the \fB\-s\fP options are specified, the -first non-option argument specifies the name of a file the shell reads -commands from; if there are no non-option arguments, the shell reads -commands from standard input. -The name of the shell (\fIi.e.\fP, the contents of the \fB$0\fP) parameter -is determined as follows: if the \fB\-c\fP option is used and there is -a non-option argument, it is used as the name; if commands are being -read from a file, the file is used as the name; otherwise the name -the shell was called with (\fIi.e.\fP, argv[0]) is used. -.PP -A shell is \fBinteractive\fP if the \fB\-i\fP option is used or -if both standard input and standard error are attached to a tty. -An interactive shell has job control enabled (if available), -ignores the INT, QUIT and TERM signals, and prints prompts before -reading input (see \fBPS1\fP and \fBPS2\fP parameters). -For non-interactive shells, the \fBtrackall\fP option is on by default -(see \fBset\fP command below). -.PP -A shell is \fBrestricted\fP if the \fB\-r\fP option is used or if either -the basename of the name the shell is invoked with or the \fBSHELL\fP -parameter match the pattern *r*sh (\fIe.g.\fP, rsh, rksh, rpdksh, \fIetc.\fP). -The following restrictions come into effect after the shell processes -any profile and \fB$ENV\fP files: -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu -the \fBcd\fP command is disabled -.IP \ \ \(bu -the \fBSHELL\fP, \fBENV\fP and \fBPATH\fP parameters can't be changed -.IP \ \ \(bu -command names can't be specified with absolute or relative paths -.IP \ \ \(bu -the \fB\-p\fP option of the \fBcommand\fP built-in can't be used -.IP \ \ \(bu -redirections that create files can't be used (\fIi.e.\fP, \fB>\fP, -\fB>|\fP, \fB>>\fP, \fB<>\fP) -.nr PD \n(P2 -.PP -A shell is \fBprivileged\fP if the \fB\-p\fP option is used or if -the real user-id or group-id does not match the effective user-id -or group-id (see \fIgetuid\fP(2), \fIgetgid\fP(2)). -A privileged shell does not process $HOME/.profile nor the \fBENV\fP -parameter (see below), instead the file /etc/suid_profile is processed. -Clearing the privileged option causes the shell to set its effective -user-id (group-id) to its real user-id (group-id). -.PP -If the basename of the name the shell is called with (\fIi.e.\fP, argv[0]) -starts with \fB\-\fP or if the \fB\-l\fP option is used, the shell is assumed -to be a login shell and the shell reads and executes the contents of -\fB/etc/profile\fP and \fB$HOME/.profile\fP if they exist and are readable. -.PP -If the \fBENV\fP parameter is set when the shell starts (or, in the -case of login shells, after any profiles are processed), its value -is subjected to parameter, command, arithmetic and tilde substitution and -the resulting file (if any) is read and executed. -If \fBENV\fP parameter is not set (and not null) and pdksh was compiled -with the \fBDEFAULT_ENV\fP macro defined, the file named in that macro -is included (after the above mentioned substitutions have been performed). -.PP -The exit status of the shell is 127 if the command file specified -on the command line could not be opened, or non-zero if a fatal syntax -error occurred during the execution of a script. -In the absence of fatal errors, the exit status is that of the last -command executed, or zero, if no command is executed. -.\"}}} -.\"{{{ Command Syntax -.SS "Command Syntax" -.\"{{{ words and tokens -The shell begins parsing its input by breaking it into \fIword\fPs. -Words, which are sequences of characters, are delimited by unquoted -\fIwhite-space\fP characters (space, tab and newline) or \fImeta-characters\fP -(\fB<\fP, \fB>\fP, \fB|\fP, \fB;\fP, \fB&\fP, \fB(\fP and \fB)\fP). -Aside from delimiting words, spaces and tabs are ignored, while -newlines usually delimit commands. -The meta-characters are used in building the following tokens: -\fB<\fP, \fB<&\fP, \fB<<\fP, \fB>\fP, \fB>&\fP, \fB>>\fP, \fIetc.\fP are -used to specify redirections (see Input/Output Redirection below); -\fB|\fP is used to create pipelines; -\fB|&\fP is used to create co-processes (see Co-Processes below); -\fB;\fP is used to separate commands; -\fB&\fP is used to create asynchronous pipelines; -\fB&&\fP and \fB||\fP are used to specify conditional execution; -\fB;;\fP is used in \fBcase\fP statements; -\fB((\fP .. \fB))\fP are used in arithmetic expressions; +.Bl -tag -width Ds +.It Fl c Ar command-string +.Nm ksh +will execute the command(s) contained in +.Ar command-string . +.It Fl i +Interactive mode; see below. +.It Fl l +Login shell; see below. +.It Fl s +The shell reads commands from standard input; all non-option arguments +are positional parameters. +.It Fl r +Restricted mode; see below. +.El +.Pp +In addition to the above, the options described in the +.Ic set +built-in command can also be used on the command line. +.Pp +If neither the +.Fl c +nor the +.Fl s +options are specified, the first non-option argument specifies the name +of a file the shell reads commands from. If there are no non-option +arguments, the shell reads commands from the standard input. The name of +the shell (i.e., the contents of $0) is determined as follows: if the +.Fl c +option is used and there is a non-option argument, it is used as the name; +if commands are being read from a file, the file is used as the name; +otherwise the name the shell was called with (i.e., argv[0]) is used. +.Pp +A shell is +.Dq interactive +if the +.Fl i +option is used or if both standard input and standard error are attached +to a tty. An interactive shell has job control enabled (if available), +ignores the +.Dv INT , +.Dv QUIT , +and +.Dv TERM +signals, and prints prompts before reading input (see +.Ev PS1 +and +.Ev PS2 +parameters). +For non-interactive shells, the +.Ic trackall +option is on by default (see +.Ic set +command below). +.Pp +A shell is +.Dq restricted +if the +.Fl r +option is used or if either the basename of the name the shell was invoked +with or the +.Ev SHELL +parameter match the pattern +.Dq \&*r\&*sh +(e.g., +.Dq rsh , +.Dq rksh , +.Dq rpdksh , +etc.). +The following restrictions come into effect after the shell processes any +profile and +.Ev ENV +files: +.Pp +.Bl -bullet -compact +.It +The +.Ic cd +command is disabled. +.It +The +.Ev SHELL , +.Ev ENV +and +.Ev PATH +parameters cannot be changed. +.It +Command names can't be specified with absolute or relative paths. +.It +The +.Fl p +option of the built-in command +.Ic command +can't be used. +.It +Redirections that create files can't be used (i.e., +.Dq > , +.Dq >| , +.Dq >> , +.Dq <> ) . +.El +.Pp +A shell is +.Dq privileged +if the +.Fl p +option is used or if the real user ID or group ID does not match the +effective user ID or group ID (see +.Xr getuid 2 +and +.Xr getgid 2 ) . +A privileged shell does not process +.Pa $HOME/.profile +nor the +.Ev ENV +parameter (see below). Instead, the file +.Pa /etc/suid_profile +is processed. Clearing the privileged option causes the shell to set +its effective user ID (group ID) to its real user ID (group ID). +.Pp +If the basename of the name the shell is called with (i.e., argv[0]) +starts with +.Dq \&- +or if the +.Fl l +option is used, +the shell is assumed to be a login shell and the shell reads and executes +the contents of +.Pa /etc/profile +and +.Pa $HOME/.profile +if they exist and are readable. +.Pp +If the +.Ev ENV +parameter is set when the shell starts (or, in the case of login shells, +after any profiles are processed), its value is subjected to parameter, +command, arithmetic, and tilde +.Pq Sq \&~ +substitution and the resulting file +(if any) is read and executed. If the +.Ev ENV +parameter is not set (and not +.Dv NULL ) +and +.Nm pdksh +was compiled with the +.Dv DEFAULT_ENV +macro defined, the file named in that macro is included (after the above +mentioned substitutions have been performed). +.Pp +The exit status of the shell is 127 if the command file specified on the +command line could not be opened, or non-zero if a fatal syntax error +occurred during the execution of a script. In the absence of fatal errors, +the exit status is that of the last command executed, or zero, if no +command is executed. +.Ss Command syntax +The shells begins parsing its input by breaking it into +.Em words . +Words, which are sequences of characters, are delimited by unquoted whitespace +characters (space, tab, and newline) or meta-characters +.Po +.Dq \&< , +.Dq \&> , +.Dq \&| , +.Dq \&; , +.Dq \&( , +and +.Dq \&) +.Pc . +Aside from delimiting words, spaces and tabs are ignored, while newlines +usually delimit commands. The meta-charcters are used in building the +following tokens: +.Dq \&< , +.Dq \&<\&& , +.Dq \&<\&< , +.Dq \&> , +.Dq \&>\&& , +.Dq \&>\&> , +etc. are used to specify redirections (see +.Sx Input/output redirection +below); +.Dq \&| +is used to create pipelines; +.Dq \&|\&& +is used to create co-processes (see +.Sx Co-processes +below); +.Dq \&; +is used to separate commands; +.Dq \&& +is used to create asynchronous pipelines; +.Dq \&&\&& +and +.Dq \&|\&| +are used to specify conditional execution; +.Dq \&;\&; +is used in +.Ic case +statements; +.Dq \&(\&( .. \&)\&) +are used in arithmetic expressions; and lastly, -\fB(\fP .. \fB)\fP are used to create subshells. -.PP -White-space and meta-characters can be quoted individually using -backslash (\fB\e\fP), or in groups using double (\fB"\fP) or single (\fB'\fP) -quotes. -Note that the following characters are also treated specially by the shell and -must be quoted if they are to represent themselves: -\fB\e\fP, \fB"\fP, \fB'\fP, \fB#\fP, \fB$\fP, \fB`\fP, \fB~\fP, \fB{\fP, -\fB}\fP, \fB*\fP, \fB?\fP and \fB[\fP. -The first three of these are the above mentioned quoting characters -(see Quoting below); -\fB#\fP, if used at the beginning of a word, introduces a comment \(em everything -after the \fB#\fP up to the nearest newline is ignored; -\fB$\fP is used to introduce parameter, command and arithmetic substitutions -(see Substitution below); -\fB`\fP introduces an old-style command substitution -(see Substitution below); -\fB~\fP begins a directory expansion (see Tilde Expansion below); -\fB{\fP and \fB}\fP delimit \fIcsh\fP(1) style alternations -(see Brace Expansion below); -and, finally, \fB*\fP, \fB?\fP and \fB[\fP are used in file name generation -(see File Name Patterns below). -.\"}}} -.\"{{{ simple-command -.PP -As words and tokens are parsed, the shell builds commands, of which -there are two basic types: \fIsimple-commands\fP, typically programs -that are executed, and \fIcompound-commands\fP, such as \fBfor\fP and -\fBif\fP statements, grouping constructs and function definitions. -.PP -A simple-command consists of some combination of parameter assignments (see -Parameters below), input/output redirections (see Input/Output Redirections -below), and command words; the only restriction is that parameter assignments -come before any command words. -The command words, if any, define the command that is to be executed and its -arguments. -The command may be a shell built-in command, a function or an \fIexternal -command\fP, \fIi.e.\fP, a separate executable file that is located using the -\fBPATH\fP parameter (see Command Execution below). -Note that all command constructs have an \fIexit status\fP: for external -commands, this is related to the status returned by \fIwait\fP(2) (if the -command could not be found, the exit status is 127, if it could not be -executed, the exit status is 126); -the exit status of other command constructs (built-in commands, functions, -compound-commands, pipelines, lists, \fIetc.\fP) are all well defined and are -described where the construct is described. -The exit status of a command consisting only of parameter assignments is that -of the last command substitution performed during the parameter assignment -or zero if there were no command substitutions. -.\"}}} -.\"{{{ pipeline -.PP -Commands can be chained together using the \fB|\fP token to -form \fIpipelines\fP, in which the standard output of each command but -the last is piped (see \fIpipe\fP(2)) to the standard input of the following -command. -The exit status of a pipeline is that of its last command. -A pipeline may be prefixed by the \fB!\fP reserved word which -causes the exit status of the pipeline to be logically -complemented: if the original status was 0 the complemented status will -be 1, and if the original status was not 0, then the complemented -status will be 0. -.\"}}} -.\"{{{ lists -.PP -\fILists\fP of commands can be created by separating pipelines by -any of the following tokens: \fB&&\fP, \fB||\fP, \fB&\fP, \fB|&\fP and \fB;\fP. -The first two are for conditional execution: \fIcmd1\fP \fB&&\fP \fIcmd2\fP -executes \fIcmd2\fP only if the exit status of \fIcmd1\fP is zero; -\fB||\fP is the opposite \(em \fIcmd2\fP is executed only if the exit status -of \fIcmd1\fP is non-zero. -\fB&&\fP and \fB||\fP have equal precedence which is higher than that of -\fB&\fP, \fB|&\fP and \fB;\fP, which also have equal precedence. -The \fB&\fP token causes the preceding command to be executed asynchronously, -that is, the shell starts the command, but does not wait for it to complete -(the shell does keep track of the status of asynchronous commands \(em see -Job Control below). -When an asynchronous command is started when job control is disabled -(\fIi.e.\fP, in most scripts), the command is started with signals INT -and QUIT ignored and with input redirected from /dev/null +.Dq \&( .. \&) +are used to create subshells. +.Pp +Whitespace and meta-characters can be quoted individually using a backslash +.Pq Sq \e , +or in groups using double +.Pq Sq \&" +or single +.Pq Sq \&' +quotes. Note that the following characters are also treated specially by the +shell and must be quoted if they are to represent themselves: +.Dq \e , +.Dq \&" , +.Dq \&' , +.Dq \&# , +.Dq \&$ , +.Dq \&` , +.Dq \&~ , +.Dq \&{ , +.Dq \&} , +.Dq \&* , +.Dq \&? , +and +.Dq \&[ . +The first three of these are the above mentioned quoting characters (see +.Sx Quoting +below); +.Dq \&# , +if used at the beginning of a word, introduces a comment -- everything after +the +.Dq \&# +up to the nearest newline is ignored; +.Dq \&$ +is used to introduce parameter, command and arithmetic substitutions (see +.Sx Substitution +below); +.Dq \&` +introduces an old-style command substitution (see +.Sx Substitution +below); +.Dq \&~ +begins a directory expansion (see +.Sx Tilde expansion +below); +.Dq \&{ +and +.Dq \&} +delimit +.Xr csh 1 +style alterations (see +.Sx Brace expansion +below); +and, finally, +.Dq \&* , +.Dq \&? , +and +.Dq \&[ +are used in file name generation (see +.Sx File name patterns +below). +.Pp +As words and tokens are parsed, the shell builds commands, of which there +are two basic types: +.Em simple-commands , +typically programs that are executed, and +.Em compound-commands , +such as +.Ic for +and +.Ic if +statements, grouping constructs and function definitions. +.Pp +A simple-command consists of some combination of parameter assignments +(see +.Sx Parameters +below), +input/output redirections (see +.Sx Input/output redirections +below), +and command words; the only restriction is that parameter assignments come +before any command words. The command words, if any, define the command +that is to be executed and its arguments. The command may be a shell built-in +command, a function or an external command (i.e., a separate executable file +that is located using the +.Ev PATH +parameter (see +.Sx Command execution +below)). +Note that all command constructs have an exit status: for external commands, +this is related to the status returned by +.Xr wait 2 +(if the command could not be found, the exit status is 127; if it could not +be executed, the exit status is 126); the exit status of other command +constructs (built-in commands, functions, compound-commands, pipelines, lists, +etc.) are all well-defined and are described where the construct is +described. The exit status of a command consisting only of parameter +assignments is that of the last command substitution performed during the +parameter assignment or 0 is there were no command substitutions. +.Pp +Commands can be chained together using the +.Dq \&| +token to form pipelines, in which the standard output of each command but the +last is piped (see +.Xr pipe 2 ) +to the standard input of the following command. The exit status of a pipeline +is that of its last command. A pipeline may be prefixed by the +.Dq \&! +reversed word which causes the exit status of the pipeline to be logically +complemented: if the original status was 0 the complemented status will be 1; +if the original status was not 0, the complemented status will be 0. +.Pp +.Em Lists +of commands can be created by separating pipelines by any of the following +tokens: +.Dq \&&\&& , +.Dq \&|\&| , +.Dq \&& , +.Dq \&|\&& , +and +.Dq \&; . +The first two are for conditional execution: +.Dq Ar cmd1 No && Ar cmd2 +executes +.Ar cmd2 +only if the exit status of +.Ar cmd1 +is zero; +.Dq \&|\&| +is the opposite -- +.Ar cmd2 +is executed only if the exit status of +.Ar cmd1 +is non-zero. +.Dq \&&\&& +and +.Dq \&|\&| +have equal precedence which is higher that that of +.Dq \&& , +.Dq \&|\&& +and +.Dq \&; , +which also have equal precedence. The +.Dq \&& +token causes the preceding command to be executed asynchronously; that is, +the shell starts the command but does not wait for it to complete (the shell +does keep track of the status of asynchronous commands, see +.Sx Job control +below). When an asynchronous command is started when job control is disabled +(i.e., in most scripts), the command is started with signals +.Dv INT +and +.Dv QUIT +ignored and with input redirected from +.Pa /dev/null (however, redirections specified in the asynchronous command have precedence). -The \fB|&\fP operator starts a \fIco-process\fP which is special kind of -asynchronous process (see Co-Processes below). -Note that a command must follow the \fB&&\fP and \fB||\fP operators, while -a command need not follow \fB&\fP, \fB|&\fP and \fB;\fP. +The +.Dq \&|\&& +operator starts a co-process which is a special kind of asynchronous process +(see +.Sx Co-processes +below). Note that a command must follow the +.Dq \&&\&& +and +.Dq \&|\&| +operators, while it need not follow +.Dq \&& , +.Dq \&|\&& +or +.Dq \&; . The exit status of a list is that of the last command executed, with the exception of asynchronous lists, for which the exit status is 0. -.\"}}} -.\"{{{ compound-commands -.PP -Compound commands are created using the following reserved words \(em these -words are only recognized if they are unquoted and if they are used as -the first word of a command (\fIi.e.\fP, they can't be preceded by parameter -assignments or redirections): +.Pp +Compound commands are created using the following reserved words. These words +are only recognized if they are unquoted and if they are used as the first +word of a command (i.e., they can't be preceded by parameter assignments or +redirections): +.Pp .TS center; lfB lfB lfB lfB lfB . -case else function then ! -do esac if time [[ -done fi in until { -elif for select while } +case else function then ! +do esac if time [[ +done fi in until { +elif for select while } .TE -\fBNote:\fP Some shells (but not this one) execute control structure commands -in a subshell when one or more of their file descriptors are redirected, so -any environment changes inside them may fail. -To be portable, the \fBexec\fP statement should be used instead to redirect -file descriptors before the control structure. -.PP +.\" +.\".Ic case , do , done , elif , +.\".Ic else , esac , fi , for , +.\".Ic function , if , in , select , +.\".Ic then , time , until , while , +.\".Ic \&! , \&[\&[ , \&{ , \&} +.Pp +NOTE: Some shells (but not this one) execute control structure commands in a +subshell when one or more of their file descriptors are redirected, so any +environment changes inside them may fail. To be portable, the +.Ic exec +statement should be used instead to redirect file descriptors before the +control structure. +.Pp In the following compound command descriptions, command lists (denoted as -\fIlist\fP) that are followed by reserved words must end with a -semi-colon, a newline or a (syntactically correct) reserved word. -For example, -.RS -\fB{ echo foo; echo bar; }\fP -.br -\fB{ echo foo; echo bar<newline>}\fP -.br -\fB{ { echo foo; echo bar; } }\fP -.RE +.Em list ) +that are followed by reserved words must end with a semi-colon, a newline or +a (syntactically correct) reserved word. For example, +.Pp +.Bl -inset -indent -compact +.It Ic { echo foo; echo bar; } +.It Ic { echo foo; echo bar<newline> } +.It Ic { { echo foo; echo bar; } } +.El +.Pp are all valid, but -.RS -\fB{ echo foo; echo bar }\fP -.RE +.Pp +.Bl -inset -indent -compact +.It Ic { echo foo; echo bar } +.El +.Pp is not. -.\"{{{ ( list ) -.IP "\fB(\fP \fIlist\fP \fB)\fP" -Execute \fIlist\fP in a subshell. There is no implicit way to pass -environment changes from a subshell back to its parent. -.\"}}} -.\"{{{ { list } -.IP "\fB{\fP \fIlist\fP \fB}\fP" -Compound construct; \fIlist\fP is executed, but not in a subshell. -Note that \fB{\fP and \fB}\fP are reserved words, not meta-characters. -.\"}}} -.\"{{{ case word in [ [ ( ] pattern [ | pattern ] ... ) list ;; ] ... esac -.IP "\fBcase\fP \fIword\fP \fBin\fP [ [\fB(\fP] \fIpattern\fP [\fB|\fP \fIpattern\fP] ... \fB)\fP \fIlist\fP \fB;;\fP ] ... \fBesac\fP" -The \fBcase\fP statement attempts to match \fIword\fP against the specified -\fIpattern\fPs; the \fIlist\fP associated with the first successfully matched -pattern is executed. Patterns used in \fBcase\fP statements are the same as -those used for file name patterns except that the restrictions regarding -\fB\&.\fP and \fB/\fP are dropped. Note that any unquoted space before and -after a pattern is stripped; any space with a pattern must be quoted. Both the -word and the patterns are subject to parameter, command, and arithmetic -substitution as well as tilde substitution. -For historical reasons, open and close braces may be used instead -of \fBin\fP and \fBesac\fP (\fIe.g.\fP, \fBcase $foo { *) echo bar; }\fP). -The exit status of a \fBcase\fP statement is that of the executed \fIlist\fP; -if no \fIlist\fP is executed, the exit status is zero. -.\"}}} -.\"{{{ for name [ in word ... term ] do list done -.IP "\fBfor\fP \fIname\fP [ \fBin\fP \fIword\fP ... \fIterm\fP ] \fBdo\fP \fIlist\fP \fBdone\fP" -where \fIterm\fP is either a newline or a \fB;\fP. -For each \fIword\fP in the specified word list, the parameter \fIname\fP is -set to the word and \fIlist\fP is executed. If \fBin\fP is not used to -specify a word list, the positional parameters (\fB"$1"\fP, \fB"$2"\fP, -\fIetc.\fP) are used instead. -For historical reasons, open and close braces may be used instead -of \fBdo\fP and \fBdone\fP (\fIe.g.\fP, \fBfor i; { echo $i; }\fP). -The exit status of a \fBfor\fP statement is the last exit status -of \fIlist\fP; if \fIlist\fP is never executed, the exit status is zero. -.\"}}} -.\"{{{ if list then list [ elif list then list ] ... [ else list ] fi -.IP "\fBif\fP \fIlist\fP \fBthen\fP \fIlist\fP [\fBelif\fP \fIlist\fP \fBthen\fP \fIlist\fP] ... [\fBelse\fP \fIlist\fP] \fBfi\fP" -If the exit status of the first \fIlist\fP is zero, the second \fIlist\fP -is executed; otherwise the \fIlist\fP following the \fBelif\fP, if any, is -executed with similar consequences. If all the lists following the \fBif\fP -and \fBelif\fPs fail (\fIi.e.\fP, exit with non-zero status), the \fIlist\fP -following the \fBelse\fP is executed. -The exit status of an \fBif\fP statement is that -of non-conditional \fIlist\fP that is executed; if no non-conditional -\fIlist\fP is executed, the exit status is zero. -.\"}}} -.\"{{{ select name [ in word ... ] do list done -.IP "\fBselect\fP \fIname\fP [ \fBin\fP \fIword\fP ... \fIterm\fP ] \fBdo\fP \fIlist\fP \fBdone\fP" -where \fIterm\fP is either a newline or a \fB;\fP. -The \fBselect\fP statement provides an automatic method of presenting -the user with a menu and selecting from it. -An enumerated list of the specified \fIwords\fP is printed on standard -error, followed by a prompt (\fBPS3\fP, normally `\fB#? \fP'). -A number corresponding to one of the enumerated words is then read -from standard input, \fIname\fP is set to the selected word (or is -unset if the selection is not valid), \fBREPLY\fP -is set to what was read (leading/trailing space is stripped), -and \fIlist\fP is executed. -If a blank line (\fIi.e.\fP, zero or more \fBIFS\fP characters) is entered, -the menu is re-printed without executing \fIlist\fP. -When \fIlist\fP completes, the enumerated list is printed if \fBREPLY\fP -is null, the prompt is printed and so on. -This process is continues until an end-of-file is read, an interrupt is -received or a break statement is executed inside the loop. -If \fBin\fP \fIword\fP \fB\&...\fP is omitted, the positional parameters -are used (\fIi.e.\fP, \fB"$1"\fP, \fB"$2"\fP, \fIetc.\fP). -For historical reasons, open and close braces may be used instead -of \fBdo\fP and \fBdone\fP (\fIe.g.\fP, \fBselect i; { echo $i; }\fP). -The exit status of a \fBselect\fP statement is zero if a break statement -is used to exit the loop, non-zero otherwise. -.\"}}} -.\"{{{ until list do list done -.IP "\fBuntil\fP \fIlist\fP \fBdo\fP \fIlist\fP \fBdone\fP" -This works like \fBwhile\fP, except that the body is executed only while the -exit status of the first \fIlist\fP is non-zero. -.\"}}} -.\"{{{ while list do list done -.IP "\fBwhile\fP \fIlist\fP \fBdo\fP \fIlist\fP \fBdone\fP" -A \fBwhile\fP is a prechecked loop. Its body is executed as often -as the exit status of the first \fIlist\fP is zero. -The exit status of a \fBwhile\fP statement is the last exit status -of the \fIlist\fP in the body of the loop; if the body is not executed, -the exit status is zero. -.\"}}} -.\"{{{ function name { list } -.IP "\fBfunction\fP \fIname\fP \fB{\fP \fIlist\fP \fB}\fP" -Defines the function \fIname\fP. -See Functions below. -Note that redirections specified after a function definition are -performed whenever the function is executed, not when the function -definition is executed. -.\"}}} -.\"{{{ name () command -.IP "\fIname\fP \fB()\fP \fIcommand\fP" -Mostly the same as \fBfunction\fP. -See Functions below. -.\"}}} -.\"{{{ (( expression )) -.IP "\fB((\fP \fIexpression\fP \fB))\fP" -The arithmetic expression \fIexpression\fP is evaluated; -equivalent to \fBlet "\fP\fIexpression\fP\fB"\fP. -See Arithmetic Expressions and the \fBlet\fP command below. -.\"}}} -.\"{{{ [[ expression ]] -.IP "\fB[[\fP \fIexpression\fP \fB]]\fP" -Similar to the \fBtest\fP and \fB[\fP \&... \fB]\fP commands (described later), -with the following exceptions: -.RS -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu -Field splitting and file name generation are not performed on -arguments. -.IP \ \ \(bu -The \fB\-a\fP (and) and \fB\-o\fP (or) operators are replaced with -\fB&&\fP and \fB||\fP, respectively. -.IP \ \ \(bu -Operators (\fIe.g.\fP, \fB\-f\fP, \fB=\fP, \fB!\fP, \fIetc.\fP) must be unquoted. -.IP \ \ \(bu -The second operand of \fB!=\fP and \fB=\fP -expressions are patterns (\fIe.g.\fP, the comparison in -.ce -\fB[[ foobar = f*r ]]\fP +.Bl -tag -width Ds +.It Ic \&( Ar list Ic \&) +Execute +.Ar list +in a subshell. There is no implicit way to pass environment changes from a +subshell back to its parent. +.It Ic \&{ Ar list Ic \&} +Compound construct; +.Ar list +is executed, but not in a subshell. Note that +.Ic \&{ +and +.Ic \&} +are reserved words, not meta-characters. +.It Xo Ic case Ar word Ic in [ +.Ns [ Ic \&( ] Ar pattern [ +.Ns Ic \&| Ar pattern ] ... Ic \&) +.Ar list Ic \&;\&; +.Ns ] Ar ... +.Ic esac +.Xc +The +.Ic case +statement attempts to match +.Ar word +against the specified +.Ar pattern Ns s ; +the +.Ar list +associated with the first successfully matched pattern is executed. Patterns +used in +.Ic case +statements are the same as those used for file name patterns except that the +restrictions regarding +.Dq \&. +and +.Dq \&/ +are dropped. Note that any unquoted space before and after a pattern is +stripped; any space with a pattern must be quoted. Both the word and the +patterns are subject to parameter, command and arithmetic substitution as +well as tilde substitution. For historical reasons, open and close braces +may be used instead of +.Ic in +and +.Ic esac +(e.g., +.Ic case $foo { *) echo bar; } ) . +The exit status of a +.Ic case +statement is that of the executed +.Ar list ; +if no +.Ar list +is executed, the exit status is zero. +.It Xo Ic for Ar name \&[ +.Ic in Ar word Ar ... Ar term \&] +.Ic do Ar list Ic done +.Xc +For each +.Ar word +in the specified word list, the parameter +.Ar name +is set to the word and +.Ar list +is executed. If +.Ic in +is not used to specify a word list, the positional parameters ($1, $2, etc.) +are used instead. For historical reasons, open and clase braces may be used +instead of +.Ic do +and +.Ic done +(e.g., +.Ic for i\&; { echo $i; } ) . +The exit status of a +.Ic for +statement is the last exit status of +.Ar list ; +if +.Ar list +is never executed, the exit status is zero. +.Ar term +is either a newline or a +.Dq \&; . +.It Xo Ic if Ar list Ic then +.Ar list [ Ic elif Ar list Ic then +.Ar list ] Ar ... [ Ic else +.Ar list ] Ic fi +.Xc +If the exit status of the first +.Ar list +is zero, the second +.Ar list +is executed; otherwise the +.Ar list +following the +.Ic elif , +if any, is executed with similar consequences. If all the lists following +the +.Ic if +and +.Ic elif Ns s +fail (i.e., exit with non-zero status), the +.Ar list +following the +.Ic else +is executed. The exit status of an +.Ic if +statement is that of non-conditional +.Ar list +that is executed; if no non-conditional +.Ar list +is executed, the exit status is zero. +.It Xo Ic select Ar name \&[ +.Ic in Ar word Ar ... Ar term \&] +.Ic do Ar list Ic done +.Xc +The +.Ic select +statement provides an automatic method of presenting the user with a menu and +selecting from it. An enumerated list of the specified +.Ar word Ns s +is printed on standard error, followed by a prompt +.Po +.Ev PS3, normally +.Dq #?\ \& +.Pc . +A number corresponding to one of the enumerated words is then read from +standard input, +.Ar name +is set to the selected word (or unset if the selection is not valid), +.Ev REPLY +is set to what was read (leading/trailing space is stripped), and +.Ar list +is executed. +If a blank line (i.e., zero or more +.Ev IFS +characters) is entered, the menu is reprinted without executing +.Ar list . +When +.Ar list +completes, the enumerated list is printed if +.Ev REPLY +is +.Dv NULL , +the prompt is printed and so on. This process continues until an end-of-file +is read, an interrupt is received, or a +.Ic break +statement is executed inside the loop. If +.Ic in Ar word Ar ... +is omitted, the positional parameters are used (i.e., $1, $2, etc.). For +historical reasons, open and close braces may be used instead of +.Ic do +and +.Ic done +(e.g., +.Ic select i; { echo $i; } ) . +The exit status of a +.Ic select +statement is zero if a break statement is used to exit the loop, non-zero +otherwise. +.It Xo Ic until Ar list Ic do Ar list +.Ic done +.Xc +This works like +.Ic while , +except that the body is executed only while the exit status of the first +.Ar list +is non-zero. +.It Xo Ic while Ar list Ic do Ar list +.Ic done +.Xc +A +.Ic while +is a pre-checked loop. Its body is executed as often as the exit status of +the first +.Ar list +is zero. The exit status of a +.Ic while +statement is the last exit status of the +.Ar list +in the body of the loop; if the body is not executed, the exit status is zero. +.It Xo Ic function Ar name Ic \&{ +.Ar list Ic \&} +.Xc +Defines the function +.Ar name +(see +.Sx Functions +below). Note that redirections specified after a function definition are +performed whenever the function is executed, not when the function definition +is executed. +.It Ar name Ic () Ar command +Mostly the same as +.Ic function +(see +.Sx Functions +below). +.It Ic (( Ar expression Ic )) +The arithmetic expression +.Ar expression +is evaluated; equivalent to +.Ic let Ar expression +(see +.Sx Arithmetic expressions +and the +.Ic let +command below). +.It Ic [[ Ar expression Ic ]] +Similar to the +.Ic test +and +.Ic \&[ Ar ... Ic \&] +commands (described later), with the following exceptions: +.Pp +.Bl -bullet -offset indent +.It +Field splitting and file name generation are not performed on arguments. +.It +The +.Fl a +(and) and +.Fl o +(or) operators are replaced with +.Dq \&&\&& +and +.Dq \&|\&| , +respectively. +.It +Operators (e.g., +.Dq Fl f , +.Dq = , +.Dq \&! , +etc.) must be unquoted. +.It +The second operand of the +.Dq \&!= +and +.Dq = +expressions are patterns (e.g., the comparison +.Ic [[ foobar = f*r ]] succeeds). -.IP \ \ \(bu -There are two additional binary operators: \fB<\fP and \fB>\fP -which return true if their first string operand is less than, -or greater than, their second string operand, respectively. -.IP \ \ \(bu -The single argument form -of \fBtest\fP, which tests if the argument has non-zero length, is not valid -- explicit operators must be always be used, \fIe.g.\fP, instead of -.ce -\fB[\fP \fIstr\fP \fB]\fP +.It +There are two additional binary operators: +.Dq \&< +and +.Dq \&> +which return true if their first string operand is less than, or greater than, +their second string operand, respectively. +.It +The single argument form of +.Ic test , +which tests if the argument has a non-zero length, is not valid; explicit +operators must always be used (e.g., instead of +.Ic \&[ Ar str Ic \&] use -.ce -\fB[[ \-n \fP\fIstr\fP\fB ]]\fP -.IP \ \ \(bu -Parameter, command and arithmetic substitutions are performed as -expressions are evaluated and lazy expression evaluation is used for -the \fB&&\fP and \fB||\fP operators. -This means that in the statement -.ce -\fB[[ -r foo && $(< foo) = b*r ]]\fP -the \fB$(< foo)\fP is evaluated if and only if the file \fBfoo\fP exists -and is readable. -.nr PD \n(P2 -.RE -.\"}}} -.\"}}} -.\"}}} -.\"{{{ Quoting -.SS Quoting +.Ic \&[[ Fl n Ar str Ic \&]] ) . +.It +Parameter, command and arithmetic substitutions are performed as expressions +are evaluated and lazy expression evaluation is used for the +.Dq \&&\&& +and +.Dq \&|\&| +operators. This means that in the statement +.Pp +.Ic \&[[ -r foo && $(< foo) = b*r ]] +.Pp +the +.Ic $(< foo) +is evaluated if and only if the file +.Pa foo +exists and is readable. +.El +.El +.Ss Quoting Quoting is used to prevent the shell from treating characters or words -specially. -There are three methods of quoting: First, \fB\e\fP quotes -the following character, unless it is at the end of a line, in which -case both the \fB\e\fP and the newline are stripped. -Second, a single quote (\fB'\fP) quotes everything up to the next single -quote (this may span lines). -Third, a double quote (\fB"\fP) quotes all characters, -except \fB$\fP, \fB`\fP and \fB\e\fP, up to the next unquoted double quote. -\fB$\fP and \fB`\fP inside double quotes have their usual meaning (\fIi.e.\fP, -parameter, command or arithmetic substitution) except no field splitting -is carried out on the results of double-quoted substitutions. -If a \fB\e\fP inside a double-quoted string is followed by \fB\e\fP, \fB$\fP, -\fB`\fP or \fB"\fP, it is replaced by the second character; if it is -followed by a newline, both the \fB\e\fP and the newline are stripped; -otherwise, both the \fB\e\fP and the character following are unchanged. -.PP -Note: see POSIX Mode below for a special rule regarding sequences -of the form \fB"\fP...\fB`\fP...\fB\e"\fP...\fB`\fP..\fB"\fP. -.\"}}} -.\"{{{ Aliases -.SS "Aliases" -There are two types of aliases: normal command aliases and tracked -aliases. Command aliases are normally used as a short hand for a long -or often used command. The shell expands command aliases (\fIi.e.\fP, -substitutes the alias name for its value) when it reads the first word -of a command. An expanded alias is re-processed to check for more -aliases. If a command alias ends in a space or tab, the following word -is also checked for alias expansion. The alias expansion process stops -when a word that is not an alias is found, when a quoted word is found -or when an alias word that is currently being expanded is found. -.PP +specially. There are three methods of quoting. First, +.Dq \e +quotes the following character, unless it is at the end of a line, in which +case both the +.Dq \e +and the newline are stripped. Second, a single quote +.Pq Sq ' +quotes everything up to the next single quote (this may span lines). Third, +a double quote +.Pq Sq \&" +quotes all characters, except +.Dq \&$ , +.Dq \&` +and +.Dq \e , +up to the next unquoted double quote. +.Dq $ +and +.Dq ` +inside double quotes have their usual meaning (i.e., parameter, command or +arithmetic substitution) except no field splitting is carried out on the +results of double-quoted substitutions. If a +.Dq \e +inside a double-quoted string is followed by +.Dq \e , +.Dq $ , +.Dq ` , +or +.Dq \&" , +it is replaced by the second character; if it is followed by a newline, both +the +.Dq \e +and the newline are stripped; otherwise, both the +.Dq \e +and the character following are unchanged. +.Pp +NOTE: See +.Sx POSIX mode +below for a special rule regarding sequences of the form +.Ic \&"...`...\e\&"...`..\&" . +.Ss Aliases +There are two types of aliases: normal command aliases and tracked aliases. +Command aliases are normally used as a short hand for a long or often used +command. The shell expands command aliases (i.e., substitutes the alias name +for its value) when it reads the first word of a command. An expanded alias +is re-processed to check for more aliases. If a command alias ends in a +space or tab, the following word is also checked for alias expansion. The +alias expansion process stops when a word that is not an alias is found, when +a quoted word is found or when an alias word that iscurrently being expanded +is found. +.Pp The following command aliases are defined automatically by the shell: -.ft B -.RS -autoload='typeset \-fu' -.br -functions='typeset \-f' -.br -hash='alias \-t' -.br -history='fc \-l' -.br -integer='typeset \-i' -.br -local='typeset' -.br -login='exec login' -.br -newgrp='exec newgrp' -.br -nohup='nohup ' -.br -r='fc \-e \-' -.br -stop='kill \-STOP' -.br -suspend='kill \-STOP $$' -.br -type='whence \-v' -.RE -.ft P -.PP +.Pp +.Bl -item -offset indent -compact +.It +.Ic autoload='typeset -fu' +.It +.Ic functions='typeset -f' +.It +.Ic hash='alias -t' +.It +.Ic history='fc -l' +.It +.Ic integer='typeset -i' +.It +.Ic local='typeset' +.It +.Ic login='exec login' +.It +.Ic newgrp='exec newgrp' +.It +.Ic nohup='nohup ' +.It +.Ic r='fc -e -' +.It +.Ic stop='kill -STOP' +.It +.Ic suspend='kill -STOP $$' +.It +.Ic type='whence -v' +.El +.Pp Tracked aliases allow the shell to remember where it found a particular -command. The first time the shell does a path search for a command that -is marked as a tracked alias, it saves the full path of the command. -The next time the command is executed, the shell checks the saved path -to see that it is still valid, and if so, avoids repeating the path -search. Tracked aliases can be listed and created using \fBalias -\-t\fP. Note that changing the \fBPATH\fP parameter clears the saved -paths for all tracked aliases. If the \fBtrackall\fP option is set (\fIi.e.\fP, -\fBset \-o trackall\fP or \fBset \-h\fP), the shell tracks all -commands. This option is set automatically for non-interactive shells. -For interactive shells, only the following commands are automatically -tracked: \fBcat\fP, \fBcc\fP, \fBchmod\fP, \fBcp\fP, \fBdate\fP, \fBed\fP, -\fBemacs\fP, \fBgrep\fP, \fBls\fP, \fBmail\fP, \fBmake\fP, \fBmv\fP, -\fBpr\fP, \fBrm\fP, \fBsed\fP, \fBsh\fP, \fBvi\fP and \fBwho\fP. -.\"}}} -.\"{{{ Substitution -.SS "Substitution" -The first step the shell takes in executing a simple-command is to -perform substitutions on the words of the command. -There are three kinds of substitution: parameter, command and arithmetic. -Parameter substitutions, which are described in detail in the next section, -take the form \fB$name\fP or \fB${\fP...\fB}\fP; command substitutions take -the form \fB$(\fP\fIcommand\fP\fB)\fP or \fB`\fP\fIcommand\fP\fB`\fP; -and arithmetic substitutions take the form \fB$((\fP\fIexpression\fP\fB))\fP. -.PP +command. The first time the shell does a path search for a command that is +marked as a tracked alias, it saves the full path of the command. The next +time the command is executed, the shell checks the saved path to see that it +is still valid, and if so, avoids repeating the path search. Tracked aliases +can be listed and created using +.Ic alias -t . +Note that changing the +.Ev PATH +parameter clears the saved paths for all tracked aliases. If the +.Ic trackall +option is set (i.e., +.Ic set Fl o Ic trackall +or +.Ic set Fl h ) , +the shell tracks all commands. This option is set automatically for +non-interactive shells. For interactive shells, only the following commands are +automatically tracked: +.Ic cat , cc , chmod , cp , +.Ic date , ed , emacs , grep , +.Ic ls , mail , make , mv , +.Ic pr , rm , sed , sh , +.Ic vi , +and +.Ic who . +.Ss Substitution +The first step the shell takes in executing a simple-command is to perform +substitutions on the words of the command. There are three kinds of +substitution: parameter, command and arithmetic. Parameter substitutions, +which are described in detail in the next section, take the form +.Ic $name +or +.Ic ${...} ; +command substitutions take the form +.Ic $( Ns Ar command Ns Ic ) +or +.Ic ` Ns Ar command Ns Ic ` ; +and arithmetic substitutions take the form +.Ic $(( Ns Ar expression Ns Ic )) . +.Pp If a substitution appears outside of double quotes, the results of the substitution are generally subject to word or field splitting according to -the current value of the \fBIFS\fP parameter. -The \fBIFS\fP parameter specifies a list of characters which -are used to break a string up into several words; -any characters from the set space, tab and newline that appear in the -IFS characters are called \fIIFS white space\fP. -Sequences of one or more IFS white space characters, in combination with -zero or one non-IFS white space characters delimit a field. -As a special case, leading and trailing IFS white space is stripped (\fIi.e.\fP, -no leading or trailing empty field is created by it); leading or trailing -non-IFS white space does create an empty field. -Example: if \fBIFS\fP is set to `<space>:', the sequence of characters -`<space>A<space>:<space><space>B::D' contains four fields: `A', `B', `' and `D'. -Note that if the \fBIFS\fP parameter is set to the null string, no -field splitting is done; if the parameter is unset, the default value -of space, tab and newline is used. -.PP -The results of substitution are, unless otherwise specified, also subject -to brace expansion and file name expansion (see the relevant sections -below). -.PP +the current value of the +.Ev IFS +parameter. The +.Ev IFS +parameter specifies a list of characters which are used to break a string up +into several words; any characters from the set space, tab and newline that +appear in the +.Ev IFS +characters are called +.Dq IFS whitespace . +Sequences of one or more +.Ev IFS +whitespace characters, in combination with zero or none non-IFS whitespace +characters delimit a field. As a special case, leading and trailing +.Ev IFS +whitespace is stripped (i.e., no leading or trailing empty field is created by +it); leading or trailing non-IFS whitespace does create an empty field. +Example: If +.Ev IFS +is set to +.Dq <space>: , +the sequence of characters +.Dq <space>A<space>:<space><space>B::D +contains four fields: +.Dq A , +.Dq B , +.Dq , +and +.Dq D . +Note that if the +.Ev IFS +parameter is set to the +.Dv NULL +string, no field splitting is done; if the parameter is unset, the default +value of space, tab and newline is used. +.Pp +The results of substitution are, unless otherwise specified, also subject to +brace expansion and file name expansion (see the relevant sections below). +.Pp A command substitution is replaced by the output generated by the specified -command, which is run in a subshell. -For \fB$(\fP\fIcommand\fP\fB)\fP substitutions, normal quoting rules -are used when \fIcommand\fP is parsed, however, for the -\fB`\fP\fIcommand\fP\fB`\fP form, a \fB\e\fP followed by any of -\fB$\fP, \fB`\fP or \fB\e\fP is stripped (a \fB\e\fP followed by any other -character is unchanged). -As a special case in command substitutions, a command of the form -\fB<\fP \fIfile\fP is interpreted to mean substitute the contents -of \fIfile\fP ($(< foo) has the same effect as $(cat foo), but it -is carried out more efficiently because no process is started). -.br -.\"todo: fix this( $(..) parenthesis counting). -NOTE: \fB$(\fP\fIcommand\fP\fB)\fP expressions are currently parsed by -finding the matching parenthesis, regardless of quoting. This will hopefully -be fixed soon. -.PP -Arithmetic substitutions are replaced by the value of the specified -expression. -For example, the command \fBecho $((2+3*4))\fP prints 14. -See Arithmetic Expressions for a description of an \fIexpression\fP. -.\"}}} -.\"{{{ Parameters -.SS "Parameters" -Parameters are shell variables; they can be assigned values and -their values can be accessed using a parameter substitution. -A parameter name is either one of the special single punctuation or digit -character parameters described below, or a letter followed by zero or more -letters or digits (`_' counts as a letter). -Parameter substitutions take the form \fB$\fP\fIname\fP or -\fB${\fP\fIname\fP\fB}\fP, where \fIname\fP is a parameter name. -If substitution is performed on a parameter that is not set, a null -string is substituted unless the \fBnounset\fP option (\fBset \-o nounset\fP -or \fBset \-u\fP) is set, in which case an error occurs. -.PP -.\"{{{ parameter assignment -Parameters can be assigned values in a number of ways. -First, the shell implicitly sets some parameters like \fB#\fP, \fBPWD\fP, -etc.; this is the only way the special single character parameters are -set. -Second, parameters are imported from the shell's environment at startup. -Third, parameters can be assigned values on the command line, for example, -`\fBFOO=bar\fP' sets the parameter FOO to bar; multiple parameter -assignments can be given on a single command line and they can -be followed by a simple-command, in which case the assignments are -in effect only for the duration of the command (such assignments are -also exported, see below for implications of this). -Note that both the parameter name and the \fB=\fP must be unquoted for -the shell to recognize a parameter assignment. -The fourth way of setting a parameter is with the \fBexport\fP, \fBreadonly\fP -and \fBtypeset\fP commands; see their descriptions in the Command Execution -section. -Fifth, \fBfor\fP and \fBselect\fP loops set parameters as well as -the \fBgetopts\fP, \fBread\fP and \fBset \-A\fP commands. -Lastly, parameters can be assigned values using assignment operators -inside arithmetic expressions (see Arithmetic Expressions below) or -using the \fB${\fP\fIname\fP\fB=\fP\fIvalue\fP\fB}\fP form -of parameter substitution (see below). -.\"}}} -.PP -.\"{{{ environment -Parameters with the export attribute (set using the \fBexport\fP or -\fBtypeset \-x\fP commands, or by parameter assignments followed by simple -commands) are put in the environment (see \fIenviron\fP(5)) of commands -run by the shell as \fIname\fP\fB=\fP\fIvalue\fP pairs. -The order in which parameters appear in the environment of a command -is unspecified. -When the shell starts up, it extracts parameters and their values from its -environment and automatically sets the export attribute for those parameters. -.\"}}} -.\"{{{ ${name[:][-+=?]word} -.PP -Modifiers can be applied to the \fB${\fP\fIname\fP\fB}\fP form of parameter -substitution: -.IP \fB${\fP\fIname\fP\fB:-\fP\fIword\fP\fB}\fP -if \fIname\fP is set and not null, it is substituted, otherwise \fIword\fP is -substituted. -.IP \fB${\fP\fIname\fP\fB:+\fP\fIword\fP\fB}\fP -if \fIname\fP is set and not null, \fIword\fP is substituted, otherwise nothing is substituted. -.IP \fB${\fP\fIname\fP\fB:=\fP\fIword\fP\fB}\fP -if \fIname\fP is set and not null, it is substituted, otherwise it is -assigned \fIword\fP and the resulting value of \fIname\fP is substituted. -.IP \fB${\fP\fIname\fP\fB:?\fP\fIword\fP\fB}\fP -if \fIname\fP is set and not null, it is substituted, otherwise \fIword\fP -is printed on standard error (preceded by \fIname\fP:) and an error occurs -(normally causing termination of a shell script, function or \&.-script). -If word is omitted the string `parameter null or not set' is used instead. -.PP -In the above modifiers, the \fB:\fP can be omitted, in which case the -conditions only depend on \fIname\fP being set (as opposed to set and -not null). -If \fIword\fP is needed, parameter, command, arithmetic and tilde substitution -are performed on it; if \fIword\fP is not needed, it is not evaluated. -.\"}}} -.PP +command, which is run in a subshell. For +.Ic $( Ns Ar command Ns Ic ) +substitutions, normal quoting rules are used when +.Ar command +is parsed, however, for the +.Ic ` Ns Ar command Ns Ic ` +form, a +.Dq \e +followed by any of +.Dq $ , +.Dq ` , +or +.Dq \e +is stripped (a +.Dq \e +followed by any other character is unchanged). As a special case in command +substitutions, a command of the form +.Ic \&< Ar file +is interpreted to mean substitute the contents of +.Ar file +(note that +.Ic $(< foo) +has the same effect as +.Ic $(cat foo) , +but it is carried out more efficiently because no process is started). +.Pp +NOTE: +.Ic $( Ns Ar command Ns Ic \&) +expressions are currently parsed by finding the matching parenthesis, +regardless of quoting. This will hopefully be fixed soon. +.Pp +Arithmetic substitutions are replaced by the value of the specified expression. +For example, the command +.Ic echo $((2+3*4)) +prints 14. See +.Sx Arithmetic expressions +for a description of an expression. +.Ss Parameters +Parameters are shell variables; they can be assigned values and their values +can be accessed using a parameter substitution. A parameter name is either one +of the special single punctuation or digit character parameters described +below, or a letter followed by zero or more letters or digits +.Po +.Dq _ +counts as a letter +.Pc . +Parameter substitutions take the form +.Ic $ Ns Ar name +or +.Ic ${ Ns Ar name Ns Ic \&} , +where +.Ar name +is a parameter name. If substitution is performed on a parameter that is not +set, a +.Dv NULL +string is substituted unless the +.Ic nounset +option +.Po +.Ic set Fl o Ic nounset +or +.Ic set Fl u +.Pc +is set, in which case an error occurs. +.Pp +Parameters can be assigned valued in a number of ways. First, the shell +implicitly sets some parameters like +.Ic # , PWD , +etc.; this is the only way the special single character parameters are set. +Second, parameters are imported from the shell's environment at startup. Third, +parameters can be assigned values on the command line, for example, +.Ic FOO=bar +sets the parameter +.Ev FOO +to +.Dq bar ; +multiple parameter assignments can be given on a single command line and they +can be followed by a simple-command, in which case the assignments are in +effect only for the duration of the command (such assignments are also +exported, see below for implications of this). Note that both the parameter +name and the +.Dq = +must be unquoted for the shell to recognize a parameter assignment. The fourth +way of setting a parameter is with the +.Ic export , +.Ic readonly +and +.Ic typeset +commands; see their descriptions in the +.Sx Command execution +section. Fifth, +.Ic for +and +.Ic select +loops set parameters as well as the +.Ic getopts , +.Ic read +and +.Ic set Fl A +commands. Lastly, parameters can be assigned values using assignment operators +inside arithmetic expressions (see +.Sx Arithmetic expressions +below) or using the +.Xo Ic ${ Ns Ar name Ns No = +.Ns Ar value Ns Ic \&} +.Xc +form of the parameter substitution (see below). +.Pp +Parameters with the export attribute (set using the +.Ic export +or +.Ic typeset Fl x +commands, or by parameter assignments followed by simple commands) are put in +the environment (see +.Xr environ 5 ) +of commands run by the shell as +.Ar name Ns No = Ns Ar value +pairs. The order in which parameters appear in the environment of a command is +unspecified. When the shell starts up, it extracts parameters and their values +from its environment and automatically sets the export attribute for those +parameters. +.Pp +Modifiers can be applied to the +.Ic ${ Ns Ar name Ns Ic \&} +form of parameter substitution: +.Bl -tag -width Ds +.It Xo Ic ${ Ns Ar name Ns +.Ic \&:\&- Ns Ar word Ns Ic \&} +.Xc +If +.Ar name +is set and not +.Dv NULL , +it is substituted, otherwise +.Ar word +is substituted. +.It Xo Ic ${ Ns Ar name Ns +.Ic \&:\&+ Ns Ar word Ns Ic \&} +.Xc +If +.Ar name +is set and not +.Dv NULL , +.Ar word +is substituted, otherwise nothing is substituted. +.It Xo Ic ${ Ns Ar name Ns +.Ic \&:\&= Ns Ar word Ns Ic \&} +.Xc +If +.Ar name +is set and not +.Dv NULL , +it is substituted, otherwise it is assigned +.Ar word +and the resulting value of +.Ar name +is substituted. +.It Xo Ic ${ Ns Ar name Ns +.Ic \&:\&? Ns Ar word Ns Ic \&} +.Xc +If +.Ar name +is set and not +.Dv NULL , +it is substituted, otherwise +.Ar word +is printed on standard error (preceded by +.Ar name Ns No \&: ) +and an error occurs (normally causing termination of a shell script, function +or .-script). If word is omitted the string +.Dq parameter null or not set +is used instead. +.El +.Pp +In the above modifiers, the +.Dq \&: +can be omitted, in which case the conditions only depand on +.Ar name +being set (as opposed to set and not +.Dv NULL ) . +If +.Ar word +is needed, parameter, command, arithmetic, and tilde substitution are performed +on it; if +.Ar word +is not needed, it is not evaluated. +.Pp The following forms of parameter substitution can also be used: -.\"{{{ ${#name} -.IP \fB${#\fP\fIname\fP\fB}\fP -The number of positional parameters if \fIname\fP is \fB*\fP, \fB@\fP or -is not specified, -or the length of the string value of parameter \fIname\fP. -.\"}}} -.\"{{{ ${#name[*]}, ${#name[@]} -.IP "\fB${#\fP\fIname\fP\fB[*]}\fP, \fB${#\fP\fIname\fP\fB[@]}\fP" -The number of elements in the array \fIname\fP. -.\"}}} -.\"{{{ ${name#pattern}, ${name##pattern} -.IP "\fB${\fP\fIname\fP\fB#\fP\fIpattern\fP\fB}\fP, \fB${\fP\fIname\fP\fB##\fP\fIpattern\fP\fB}\fP" -If \fIpattern\fP matches the beginning of the value of parameter \fIname\fP, -the matched text is deleted from the result of substitution. A single -\fB#\fP results in the shortest match, two \fB#\fP's results in the -longest match. -.\"}}} -.\"{{{ ${name%pattern}, ${name%%pattern} -.IP "\fB${\fP\fIname\fP\fB%\fP\fIpattern\fP\fB}\fP, \fB${\fP\fIname\fP\fB%%\fP\fIpattern\fP\fB}\fP" -Like \fB${\fP..\fB#\fP..\fB}\fP substitution, but it deletes from the end of the -value. -.\"}}} -.\"{{{ special shell parameters -.PP +.Bl -tag -width Ds +.It Ic ${# Ns Ar name Ns Ic \&} +The number of positional parameters if +.Ar name +is +.Dq \&* , +.Dq \&@ , +not specified, or the length of the string value of parameter +.Ar name . +.It Xo Ic ${# Ns Ar name Ns +.Ic \&[\&*\&]\&} , ${# Ns Ar name Ns Ic \&[\&@\&]\&} +.Xc +The number of elements in the array +.Ar name . +.Sm off +.It Xo +.Ic ${ Ar name Ic \&# Ar pattern Ic \&},\ \& +.Ic ${ Ar name Ic \&#\&# Ar pattern Ic \&} +.Xc +.Sm on +If +.Ar pattern +matches the beginning of the value of parameter +.Ar name , +the matched text is deleted from the result of substitution. A single +.Dq \&# +results in the shortest match, two +of them results in the longest match. +.Sm off +.It Xo +.Ic ${ Ar name Ic \&% Ar pattern Ic \&},\ \& +.Ic ${ Ar name Ic \&%\&% Ar pattern Ic \&} +.Xc +.Sm on +Like +.Ic ${..#..} +substitution, but it deletes from the end of the value. +.El +.Pp The following special parameters are implicitly set by the shell and cannot be set directly using assignments: -.\"{{{ ! -.IP \fB!\fP -Process id of the last background process started. If no background -processes have been started, the parameter is not set. -.\"}}} -.\"{{{ # -.IP \fB#\fP -The number of positional parameters (\fIi.e.\fP, \fB$1\fP, \fB$2\fP, -\fIetc.\fP). -.\"}}} -.\"{{{ $ -.IP \fB$\fP -The process ID of the shell, or the PID of the original shell if -it is a subshell. -.\"}}} -.\"{{{ - -.IP \fB\-\fP -The concatenation of the current single letter options -(see \fBset\fP command below for list of options). -.\"}}} -.\"{{{ ? -.IP \fB?\fP -The exit status of the last non-asynchronous command executed. -If the last command was killed by a signal, \fB$?\fP is set to 128 plus -the signal number. -.\"}}} -.\"{{{ 0 -.IP "\fB0\fP" -The name the shell was invoked with (\fIi.e.\fP, \fBargv[0]\fP), or the -\fBcommand-name\fP if it was invoked with the \fB\-c\fP option and the -\fBcommand-name\fP was supplied, or the \fIfile\fP argument, if it was -supplied. -If the \fBposix\fP option is not set, \fB$0\fP is the name of the current -function or script. -.\"}}} -.\"{{{ 1-9 -.IP "\fB1\fP ... \fB9\fP" -The first nine positional parameters that were supplied to the shell, -function or \fB.\fP-script. -Further positional parameters may be accessed using -\fB${\fP\fInumber\fP\fB}\fP. -.\"}}} -.\"{{{ * -.IP \fB*\fP -All positional parameters (except parameter 0), -\fIi.e.\fP, \fB$1 $2 $3\fP.... -If used outside of double quotes, parameters are separate words -(which are subjected to word splitting); if used within double quotes, -parameters are separated by the first character of the \fBIFS\fP parameter -(or the empty string if \fBIFS\fP is null). -.\"}}} -.\"{{{ @ -.IP \fB@\fP -Same as \fB$*\fP, unless it is used inside double quotes, in which case -a separate word is generated for each positional parameter \- if there -are no positional parameters, no word is generated ("$@" can be used -to access arguments, verbatim, without loosing null arguments or -splitting arguments with spaces). -.\"}}} -.\"}}} -.\"{{{ general shell parameters -.PP +.Bl -tag -width "1 ... 9" +.It Ev \&! +Process ID of the last background process started. If no background processes +have been started, the parameter is not set. +.It Ev \&# +The number of positional parameters (i.e., $1, $2, etc.). +.It Ev \&$ +The process ID of the shell, or the PID of the original shell if it is a +subshell. +.It Ev \&- +The concatenation of the current single letter options (see +.Ic set +command below for list of options). +.It Ev \&? +The exit status of the last non-asynchronous command executed. If the last +command was killed by a signal, +.Ic \&$\&? +is set to 128 plus the signal number. +.It Ev 0 +The name the shell was invoked with (i.e., +.Ic argv[0] ) , +or the +.Ar command-name +if it was invoked with the +.Fl c +option and the +.Ar command-name +was supplied, or the +.Ar file +argument, if it was supplied. If the +.Ic posix +option is not set, +.Ic \&$0 +is the name of the current function or script. +.It Ev 1 ... Ev 9 +The first nine positional parameters that were supplied to the shell, function +or .-script. Further positional parameters may be accessed using +.Ic ${ Ns Ar number Ns Ic \&} . +.It Ev \&* +All positional parameters (except parameter 0), i.e., $1, $2, $3... If used +outside of double quotes, parameters are separate words (which are subjected +to word splitting); if used within double quotes, parameters are separated +by the first character of the +.Ev IFS +parameter (or the empty string if +.Ev IFS +is +.Dv NULL ) . +.It Ev \&@ +Same as +.Ic \&$\&* , +unless it is used inside double quotes, in which case a separate word is +generated for each positional parameter. If there are no positional parameters, +no word is generated. +.Ic \&$\&@ +can be used to access arguments, verbatim, without losing +.Dv NULL +arguments or splitting arguments with spaces. +.El +.Pp The following parameters are set and/or used by the shell: -.\"{{{ _ -.IP "\fB_\fP \fI(underscore)\fP" -When an external command is executed by the shell, this parameter is -set in the environment of the new process to the path of the executed -command. -In interactive use, this parameter is also set in the parent shell to -the last word of the previous command. -When \fBMAILPATH\fP messages are evaluated, this parameter contains -the name of the file that changed (see \fBMAILPATH\fP parameter below). -.\"}}} -.\"{{{ CDPATH -.IP \fBCDPATH\fP -Search path for the \fBcd\fP built-in command. Works the same way as -\fBPATH\fP for those directories not beginning with \fB/\fP in \fBcd\fP -commands. -Note that if CDPATH is set and does not contain \fB.\fP nor an empty path, -the current directory is not searched. Also, the \fBcd\fP built-in command -will display the resulting directory when a match is found in any search path -other than the than the empty path. -.\"}}} -.\"{{{ COLUMNS -.IP \fBCOLUMNS\fP -Set to the number of columns on the terminal or window. -Currently set to the \fBcols\fP value as reported by \fIstty\fP(1) if that -value is non-zero. -This parameter is used by the interactive line editing modes, and by -\fBselect\fP, \fBset \-o\fP and \fBkill \-l\fP commands -to format information in columns. -.\"}}} -.\"{{{ EDITOR -.IP \fBEDITOR\fP -If the \fBVISUAL\fP parameter is not set, this parameter controls the -command line editing mode for interactive shells. -See \fBVISUAL\fP parameter below for how this works. -.\"}}} -.\"{{{ ENV -.IP \fBENV\fP -If this parameter is found to be set after any profile files are -executed, the expanded value is used as a shell start-up file. It -typically contains function and alias definitions. -.\"}}} -.\"{{{ ERRNO -.IP \fBERRNO\fP -Integer value of the shell's errno variable \(em indicates the reason -the last system call failed. -.\" todo: ERRNO variable -.sp -Not implemented yet. -.\"}}} -.\"{{{ EXECSHELL -.IP \fBEXECSHELL\fP -If set, this parameter is assumed to contain the shell that is to be -used to execute commands that \fIexecve\fP(2) fails to execute and -which do not start with a `\fB#!\fP \fIshell\fP' sequence. -.\"}}} -.\"{{{ FCEDIT -.IP \fBFCEDIT\fP -The editor used by the \fBfc\fP command (see below). -.\"}}} -.\"{{{ FPATH -.IP \fBFPATH\fP -Like \fBPATH\fP, but used when an undefined function is executed to locate -the file defining the function. -It is also searched when a command can't be found using \fBPATH\fP. -See Functions below for more information. -.\"}}} -.\"{{{ HISTFILE -.IP \fBHISTFILE\fP -The name of the file used to store history. -When assigned to, history is loaded from the specified file. -Also, several invocations of the -shell running on the same machine will share history if their -\fBHISTFILE\fP parameters all point at the same file. -.br -NOTE: if HISTFILE isn't set, no history file is used. This is -different from the original Korn shell, which uses \fB$HOME/.sh_history\fP; -in future, pdksh may also use a default history file. -.\"}}} -.\"{{{ HISTSIZE -.IP \fBHISTSIZE\fP -The number of commands normally stored for history, default 128. -.\"}}} -.\"{{{ HOME -.IP \fBHOME\fP -The default directory for the \fBcd\fP command and the value -substituted for an unqualified \fB~\fP (see Tilde Expansion below). -.\"}}} -.\"{{{ IFS -.IP \fBIFS\fP -Internal field separator, used during substitution and by the \fBread\fP -command, to split values into distinct arguments; normally set to -space, tab and newline. See Substitution above for details. -.br -\fBNote:\fP this parameter is not imported from the environment -when the shell is started. -.\"}}} -.\"{{{ KSH_VERSION -.IP \fBKSH_VERSION\fP -The version of shell and the date the version was created (readonly). -See also the version commands in Emacs Interactive Input Line Editing -and Vi Interactive Input Line Editing, below. -.\"}}} -.\"{{{ SH_VERSION -.\"}}} -.\"{{{ LINENO -.IP \fBLINENO\fP +.Bl -tag -width "EXECSHELL" +.It Ev \&_ No (underscore) +When an external command is executed by the shell, this parameter is set in the +environment of the new process to the path of the executed command. In +interactive use, this parameter is also set in the parent shell to the last +word of the previous command. When +.Ev MAILPATH +messages are evaluated, this parameter contains the name of the file that +changed (see +.Ev MAILPATH +parameter below). +.It Ev CDPATH +Search path for the +.Ic cd +built-in command. Works the same way as +.Ev PATH +for those directories not beginning with +.Dq \&/ +in +.Ic cd +commands. Note that if +.Ev CDPATH +is set and does not contain +.Dq \&. +or contains an empty path, the current directory is not searched. Also, the +.Ic cd +built-in command will display the resulting directory when a match is found +in any search path other than the empty path. +.It Ev COLUMNS +Set to the number of columns on the terminal or window. Currently set to the +.Dq cols +value as reported by +.Xr stty 1 +if that value is non-zero. This parameter is used by the interactive line +editing modes, and by +.Ic select , +.Ic set Fl o +and +.Ic kill -l +commands to format information columns. +.It Ev EDITOR +If the +.Ev VISUAL +parameter is not set, this parameter controls the command line editing mode for +interactive shells. See +.Ev VISUAL +parameter below for how this works. +.It Ev ENV +If this parameter is found to be set after any profile files are executed, the +expanded value is used as a shell startup file. It typically contains function +and alias definitions. +.It Ev ERRNO +Integer value of the shell's +.Va errno +variable. It indicates the reason the last system call failed. Not yet +implemented. +.It Ev EXECSHELL +If set, this parameter is assumed to contain the shell that is to be used to +execute commands that +.Fn execve 2 +fails to execute and which do not start with a +.Dq \&#\&! Ns Ar shell +sequence. +.It Ev FCEDIT +The editor used by the +.Ic fc +command (see below). +.It Ev FPATH +Like +.Ev PATH , +but used when an undefined function is executed to locate the file defining the +function. It is also searched when a command can't be found using +.Ev PATH . +See +.Sx Functions +below for more information. +.It Ev HISTFILE +The name of the file used to store command history. When assigned to, history +is loaded from the specified file. Also, several invocations of the shell +running on the same machine will share history if their +.Ev HISTFILE +parameters all point to the same file. +.Pp +NOTE: If +.Ev HISTFILE +isn't set, no history file is used. This is different from the original Korn +shell, which uses +.Pa $HOME/.sh_history ; +in future, +.Nm pdksh +may also use a default history file. +.It Ev HISTSIZE +The number of commands normally stored for history. The default is 128. +.It Ev HOME +The default directory for the +.Ic cd +command and the value substituted for an unqualified +.Ic ~ +(see +.Sx Tilde expansion +below). +.It Ev IFS +Internal field separator, used during substitution and by the +.Ic read +command, to split values into distinct arguments; normally set to space, tab +and newline. See +.Sx Substitution +above for details. +.Pp +NOTE: This parameter is not imported from the environment when the shell is +started. +.It Ev KSH_VERSION +The version of the shell and the date the version was created (read-only). +See also the version commands in +.Sx Emacs interactive input line editing +and +.Sx Vi interactive input line editing , +below. +.It Ev LINENO The line number of the function or shell script that is currently being -executed. -.\" todo: LINENO variable -.sp -Not implemented yet. -.\"}}} -.\"{{{ LINES -.IP \fBLINES\fP -Set to the number of lines on the terminal or window. -.\"Currently set to the \fBrows\fP value as reported by \fIstty\fP(1) if that -.\"value is non-zero. -.\" todo: LINES variable -.sp -Not implemented yet. -.\"}}} -.\"{{{ MAIL -.IP \fBMAIL\fP -If set, the user will be informed of the arrival of mail in the named -file. This parameter is ignored if the \fBMAILPATH\fP parameter is set. -.\"}}} -.\"{{{ MAILCHECK -.IP \fBMAILCHECK\fP -How often, in seconds, the shell will check for mail in the file(s) -specified by \fBMAIL\fP or \fBMAILPATH\fP. If 0, the shell checks -before each prompt. The default is 600 (10 minutes). -.\"}}} -.\"{{{ MAILPATH -.IP \fBMAILPATH\fP -A list of files to be checked for mail. The list is colon separated, -and each file may be followed by a \fB?\fP and a message to be printed -if new mail has arrived. Command, parameter and arithmetic substitution is -performed on the message, and, during substitution, the parameter \fB$_\fP -contains the name of the file. -The default message is \fByou have mail in $_\fP. -.\"}}} -.\"{{{ OLDPWD -.IP \fBOLDPWD\fP -The previous working directory. -Unset if \fBcd\fP has not successfully changed directories since the -shell started, or if the shell doesn't know where it is. -.\"}}} -.\"{{{ OPTARG -.IP \fBOPTARG\fP -When using \fBgetopts\fP, it contains the argument for a parsed option, -if it requires one. -.\"}}} -.\"{{{ OPTIND -.IP \fBOPTIND\fP -The index of the last argument processed when using \fBgetopts\fP. -Assigning 1 to this parameter causes \fBgetopts\fP to -process arguments from the beginning the next time it is invoked. -.\"}}} -.\"{{{ PATH -.IP \fBPATH\fP -A colon separated list of directories that are searched when looking -for commands and \fB.\fP'd files. -An empty string resulting from a leading or trailing colon, or two adjacent -colons is treated as a `.', the current directory. -.\"}}} -.\"{{{ POSIXLY_CORRECT -.IP \fBPOSIXLY_CORRECT\fP -If set, this parameter causes the \fBposix\fP option to be enabled. -See POSIX Mode below. -.\"}}} -.\"{{{ PPID -.IP \fBPPID\fP -The process ID of the shell's parent (readonly). -.\"}}} -.\"{{{ PS1 -.IP \fBPS1\fP -\fBPS1\fP is the primary prompt for interactive shells. -Parameter, command and arithmetic substitutions are performed, and -\fB!\fP is replaced with the current command number (see \fBfc\fP -command below). A literal ! can be put in the prompt by placing !! in PS1. -Note that since the command line editors try to figure out how long the -prompt is (so they know how far it is to edge of the screen), -escape codes in the prompt tend to mess things up. -You can tell the shell not to count certain sequences (such as escape codes) -by prefixing your prompt with a non-printing character (such as control-A) -followed by a carriage return and then delimiting the escape codes with -this non-printing character. -If you don't have any non-printing characters, you're out of luck... -BTW, don't blame me for this hack; it's in the original ksh. -Default is `\fB$\ \fP' for non-root users, `\fB#\ \fP' for root.. -.\"}}} -.\"{{{ PS2 -.IP \fBPS2\fP -Secondary prompt string, by default `\fB>\fP ', used when more input is -needed to complete a command. -.\"}}} -.\"{{{ PS3 -.IP \fBPS3\fP -Prompt used by \fBselect\fP statement when reading a menu selection. -Default is `\fB#?\ \fP'. -.\"}}} -.\"{{{ PS4 -.IP \fBPS4\fP -Used to prefix commands that are printed during execution tracing -(see \fBset \-x\fP command below). -Parameter, command and arithmetic substitutions are performed -before it is printed. -Default is `\fB+\ \fP'. -.\"}}} -.\"{{{ PWD -.IP \fBPWD\fP -The current working directory. Maybe unset or null if shell doesn't -know where it is. -.\"}}} -.\"{{{ RANDOM -.IP \fBRANDOM\fP -A simple random number generator. Every time \fBRANDOM\fP is -referenced, it is assigned the next number in a random number series. -The point in the series can be set by assigning a number to -\fBRANDOM\fP (see \fIrand\fP(3)). -.\"}}} -.\"{{{ REPLY -.IP \fBREPLY\fP -Default parameter for the \fBread\fP command if no names are given. -Also used in \fBselect\fP loops to store the value that is read from -standard input. -.\"}}} -.\"{{{ SECONDS -.IP \fBSECONDS\fP +executed. Not yet implemented. +.It Ev LINES +Set to the number of lines on the terminal or window. Not yet implemented. +.It Ev MAIL +If set, the user will be informed of the arrival of mail in the named file. +This parameter is ignored if the +.Ev MAILPATH +parameter is set. +.It Ev MAILCHECK +How often, in seconds, the shell will check for mail in the file(s) specified +by +.Ev MAIL +or +.Ev MAILPATH . +If set to 0, the shell checks before each prompt. The default is 600 (10 +minutes). +.It Ev MAILPATH +A list of files to be checked for mail. The list is colon separated, and each +file may be followed by a +.Dq \&? +and a message to be printed if new mail has arrived. Command, parameter and +arithmetic substitution is performed on the message, and, during substitution, +the parameter +.Ev $_ +contains the name of the file. The default message is +.Dq you have mail in $_ . +.It Ev OLDPWD +The previous working directory. Unset if +.Ic cd +has not successfully changed directories since the shell started, or if the +shell doesn't know where it is. +.It Ev OPTARG +When using +.Ic getopts , +it contains the argument for a parsed option, if it requires one. +.It Ev OPTIND +The index of the last argument processed when using +.Ic getopts . +Assigning 1 to this parameter causes +.Ic getopts +to process arguments from the beginning the next time it is invoked. +.It Ev PATH +A colon separated list of directories that are searched when looking for +commands and .'d files. An empty string resulting from a leading or trailing +colon, or two adjacent colons, is treated as a +.Dq \&. , +the current directory. +.It Ev POSIXLY_CORRECT +If set, this parameter causes the +.Ic posix +option to be enabled. See +.Sx POSIX mode +below. +.It Ev PPID +The process ID of the shell's parent (read-only). +.It Ev PS1 +The primary prompt for interactive shells. Parameter, command and arithmetic +substitutions are performed, and +.Dq \&! +is replaced with the current command number (see +.Ic fc +command below). A literal +.Dq \&! +can be put in the prompt by placing +.Dq \&!\&! +in +.Ev PS1 . +Note that since the command line editors try to figure out how long the prompt +is (so they know how far it is to the edge of the screen), escape codes in +the prompt tend to mess things up. You can tell the shell not to count cetain +sequences (such as escape codes) by prefixing your prompt with a non-printing +character (such as control-A) followed by a carriage return and then delimiting +the escape codes with this non-printing character. If you don't have any +non-printing characters, you're out of luck. By the way, don't blame me for +this hack; it's in the original +.Xr ksh . +Default is +.Dq \&$\ \& +for non-root users, +.Dq \&#\ \& +for root. +.It Ev PS2 +Secondary prompt string, by default +.Dq \&>\ \& , +used when more input is needed to complete a command. +.It Ev PS3 +Prompt used by +.Ic select +statement when reading a menu selection. Default is +.Dq \&#\&?\ \& . +.It Ev PS4 +Used to prefix commands that are printed during execution tracing (see +.Ic set Fl x +command below). Parameter, command and arithmetic substitutions are performed +before it is printed. Default is +.Dq \&+\ \& . +.It Ev PWD +The current working directory. May be unset or +.Dv NULL +if the shell doesn't know where it is. +.It Ev RANDOM +A simple random number generator. Every time +.Ev RANDOM +is referenced, it is assigned the next number in a random number series. The +point in the series can be set by assigning a number to +.Ev RANDOM +(see +.Xr rand 3 ) . +.It Ev REPLY +Default parameter for the +.Ic read +command if no names are given. Also used in +.Ic select +loops to store the value that is read from standard input. +.It Ev SECONDS The number of seconds since the shell started or, if the parameter has been -assigned an integer value, the number of seconds since the assignment plus -the value that was assigned. -.\"}}} -.\"{{{ TMOUT -.IP \fBTMOUT\fP -If set to a positive integer in an interactive shell, it specifies -the maximum number of seconds the shell will wait for input after -printing the primary prompt (\fBPS1\fP). If the time is exceeded, the -shell exits. -.\"}}} -.\"{{{ TMPDIR -.IP \fBTMPDIR\fP -The directory shell temporary files are created in. If this parameter -is not set, or does not contain the absolute path of a writable -directory, temporary files are created in \fB/tmp\fP. -.\"}}} -.\"{{{ VISUAL -.IP \fBVISUAL\fP -If set, this parameter controls the command line editing mode for -interactive shells. If the last component of the path specified in this -parameter contains the string \fBvi\fP, \fBemacs\fP or \fBgmacs\fP, the -vi, emacs or gmacs (Gosling emacs) editing mode is enabled, respectively. -.\"}}} -.\"}}} -.\"}}} -.\"{{{ Tilde Expansion -.SS "Tilde Expansion" -Tilde expansion, which is done in parallel with parameter substitution, -is done on words starting with an unquoted \fB~\fP. The characters -following the tilde, up to the first \fB/\fP, if any, are assumed to be -a login name. If the login name is empty, \fB+\fP or \fB\-\fP, the -value of the \fBHOME\fP, \fBPWD\fP, or \fBOLDPWD\fP parameter is -substituted, respectively. Otherwise, the password file is searched for -the login name, and the tilde expression is substituted with the -user's home directory. If the login name is not found in the password -file or if any quoting or parameter substitution occurs in the login name, -no substitution is performed. -.PP -In parameter assignments (those preceding a simple-command or those -occurring in the arguments of \fBalias\fP, \fBexport\fP, \fBreadonly\fP, -and \fBtypeset\fP), tilde expansion is done after any unquoted colon -(\fB:\fP), and login names are also delimited by colons. -.PP -The home directory of previously expanded login names are cached and -re-used. The \fBalias \-d\fP command may be used to list, change and -add to this cache (\fIe.g.\fP, `alias \-d fac=/usr/local/facilities; cd -~fac/bin'). -.\"}}} -.\"{{{ Brace Expansion -.SS "Brace Expansion (alternation)" +assigned an integer value, the number of seconds since the assignment plus the +value that was assigned. +.It Ev TMOUT +If set to a positive integer in an interactive shell, it specifies the maximum +number of seconds the shell will wait for input after priting the primary +prompt +.Pq Ev PS1 . +If the time is exceeded, the shell exits. +.It Ev TMPDIR +The directory shell temporary files are created in. If this parameter is not +set, or does not contain the absolute path of a writable directory, temporary +files are created in +.Pa /tmp . +.It Ev VISUAL +If set, this parameter controls the command line editing mode for interactive +shells. If the last component of the path specified in this parameter contains +the string +.Dq vi , +.Dq emacs +or +.Dq gmacs , +the +.Xr vi , +.Xr emacs +or +.Xr gmacs +(Gosling emacs) editing mode is enabled, respectively. +.El +.Ss Tilde expansion +Tilde expansion, which is done in parallel with parameter substitution, is done +on words starting with an unquoted +.Dq ~ . +The characters following the tilde, up to the first +.Dq / , +if any, are assumed to be a login name. If the login name is empty, +.Dq \&+ +or +.Dq \&- , +the value of the +.Ev HOME , PWD +or +.Ev OLDPWD +parameter is substituted, respectively. Otherwise, the password file is +searched for the login name, and the tilde expression is substituted with the +user's home directory. If the login name is not found in the password file or +if any quoting or parameter substitution occurs in the login name, no +substitution is performed. +.Pp +In parameter assignments (those preceding a simple-command or those occurring +in the arguments of +.Ic alias , +.Ic export , +.Ic readonly , +and +.Ic typeset ) , +tilde expansion is done after any unquoted colon +.Pq Sq \&: , +and login names are also delimited by colons. +The home directory of previously expanded login names are cached and re-used. +The +.Ic alias -d +command may be used to list, change and add to this cache (e.g., +.Ic alias -d fac=/usr/local/facilities; cd ~fac/bin ) . +.Ss Brace expansion (alteration) Brace expressions, which take the form -.RS -\fIprefix\fP\fB{\fP\fIstr\fP1\fB,\fP...\fB,\fP\fIstr\fPN\fB}\fP\fIsuffix\fP -.RE +.Pp +.Sm off +.D1 Xo Ar prefix Ic { Ar str No 1,..., +.Ar str No N Ic } Ar suffix +.Xc +.Sm on +.Pp are expanded to N words, each of which is the concatenation of -\fIprefix\fP, \fIstr\fPi and \fIsuffix\fP -(\fIe.g.\fP, `a{c,b{X,Y},d}e' expands to four word: ace, abXe, abYe, and ade). +.Ar prefix , +.Ar str Ns i +and +.Ar suffix +(e.g., +.Dq a{c,b{X,Y},d}e +expands to four words: +.Dq ace , +.Dq abXe , +.Dq abYe , +and +.Dq ade ) . As noted in the example, brace expressions can be nested and the resulting -words are not sorted. -Brace expressions must contain an unquoted comma (\fB,\fP) for expansion -to occur (\fIi.e.\fP, \fB{}\fP and \fB{foo}\fP are not expanded). -Brace expansion is carried out after parameter substitution and before -file name generation. -.\"}}} -.\"{{{ File Name Patterns -.SS "File Name Patterns" -.PP -A file name pattern is a word containing one or more unquoted \fB?\fP or -\fB*\fP characters or \fB[\fP..\fB]\fP sequences. Once brace expansion has -been performed, the shell replaces file name patterns with the sorted names -of all the files that match the pattern (if no files match, the word is -left unchanged). The pattern elements have the following meaning: -.IP \fB?\fP -matches any single character. -.IP \fB*\fP -matches any sequence of characters. -.IP \fB[\fP..\fB]\fP -matches any of the characters inside the brackets. Ranges of characters -can be specified by separating two characters by a \fB\-\fP, \fIe.g.\fP, -\fB[a0\-9]\fP matches the letter \fBa\fP or any digit. -In order to represent itself, a -\fB\-\fP must either be quoted or the first or last character in the character -list. Similarly, a \fB]\fP must be quoted or the first character in the list -if it is represent itself instead of the end of the list. Also, a \fB!\fP +words are not sorted. Brace expressions must contain an unquoted comma +.Pq Sq \&, +for expansion to occur (i.e., +.Ic {} +and +.Ic {foo} +are not expanded). Brace expansion is carried out after parameter substitution +and before file name generation. +.Ss File name patterns +A file name pattern is a word containing one or more unquoted +.Dq \&? +or +.Dq \&* +characters or +.Dq [..] +sequences. Once brace expansion has been performed, the shell replaces file +name patterns with the sorted named of all the files that match the pattern +(if no files match, the word is left unchanged). The pattern elements have the +following meaning: +.Bl -tag -width Ds +.It Ic \&? +Matches any single character. +.It Ic \&* +Matches any sequence of characters. +.It Ic \&[ Ns No .. Ns Ic \&] +Matches any of the characters inside the brackets. Ranges of characters can be +specified by separating two characters by a +.Dq \&- +(e.g., +.Dq [a0-9] +matches the letter +.Dq a +or any digit). In order to represent itself, a +.Dq \&- +must either be quoted or the first or last character in the character list. +Similarly, a +.Dq \&] +must be quoted or the first character in the list if it is to represent itself +instead of the end of the list. Also, a +.Dq \&! appearing at the start of the list has special meaning (see below), so to represent itself it must be quoted or appear later in the list. -.IP \fB[!\fP..\fB]\fP -like \fB[\fP..\fB]\fP, except it matches any character not inside the brackets. -.IP "\fB*(\fP\fIpattern\fP\fB|\fP ... \fP|\fP\fIpattern\fP\fB)\fP" -matches any string of characters that matches zero or more occurances -of the specified patterns. -Example: the pattern \fB*(foo|bar)\fP matches the strings -`', `foo', `bar', `foobarfoo', \fIetc.\fP. -.IP "\fB+(\fP\fIpattern\fP\fB|\fP ... \fP|\fP\fIpattern\fP\fB)\fP" -matches any string of characters that matches one or more occurances -of the specified patterns. -Example: the pattern \fB+(foo|bar)\fP matches the strings -`foo', `bar', `foobarfoo', \fIetc.\fP. -.IP "\fB?(\fP\fIpattern\fP\fB|\fP ... \fP|\fP\fIpattern\fP\fB)\fP" -matches the empty string or a string that matches one of the -specified patterns. -Example: the pattern \fB?(foo|bar)\fP only matches the strings -`', `foo' and `bar'. -.IP "\fB@(\fP\fIpattern\fP\fB|\fP ... \fP|\fP\fIpattern\fP\fB)\fP" -matches a string that matches one of the -specified patterns. -Example: the pattern \fB@(foo|bar)\fP only matches the strings -`foo' and `bar'. -.IP "\fB!(\fP\fIpattern\fP\fB|\fP ... \fP|\fP\fIpattern\fP\fB)\fP" -matches any string that does not match one of the specified -patterns. -Examples: the pattern \fB!(foo|bar)\fP matches all strings except -`foo' and `bar'; the pattern \fB!(*)\fP matches no strings; -the pattern \fB!(?)*\fP matches all strings (think about it). -.PP -Note that pdksh currently never matches \fB.\fP and \fB..\fP, but the original -ksh, Bourne sh and bash do, so this may have to change (too bad). -.PP -Note that none of the above pattern elements match either a period (\fB.\fP) -at the start of a file name or a slash (\fB/\fP), even if they are explicitly -used in a \fB[\fP..\fB]\fP sequence; also, the names \fB.\fP and \fB..\fP -are never matched, even by the pattern \fB.*\fP. -.PP -If the \fBmarkdirs\fP option is set, any directories that result from -file name generation are marked with a trailing \fB/\fP. -.PP -.\" todo: implement this ([[:alpha:]], \fIetc.\fP) -The POSIX character classes (\fIi.e.\fP, -\fB[:\fP\fIclass-name\fP\fB:]\fP inside a \fB[\fP..\fB]\fP expression) -are not yet implemented. -.\"}}} -.\"{{{ Input/Output Redirection -.SS "Input/Output Redirection" -When a command is executed, its standard input, standard output and -standard error (file descriptors 0, 1 and 2, respectively) are normally -inherited from the shell. -Three exceptions to this are commands in pipelines, for which standard input -and/or standard output are those set up by the pipeline, asynchronous commands -created when job control is disabled, for which standard input is initially -set to be from \fB/dev/null\fP, and commands for which any of the following -redirections have been specified: -.IP "\fB>\fP \fIfile\fP" -standard output is redirected to \fIfile\fP. If \fIfile\fP does not exist, -it is created; if it does exist, is a regular file and the \fBnoclobber\fP -option is set, an error occurs, otherwise the file is truncated. -Note that this means the command \fIcmd < foo > foo\fP will open -\fIfoo\fP for reading and then truncate it when it opens it for writing, -before \fIcmd\fP gets a chance to actually read \fIfoo\fP. -.IP "\fB>|\fP \fIfile\fP" -same as \fB>\fP, except the file is truncated, even if the \fBnoclobber\fP +.It Ic \&[\&! Ns No .. Ns Ic \&] +Like +.Ic \&[ Ns No .. Ns Ic \&] , +except it matches any character not inside the brackets. +.Sm off +.It Xo Ic \&*( Ar pattern Ic \&| No \ ...\ +.Ic \&| Ar pattern Ic \&) +.Xc +.Sm on +Matches any string of characters that matches zero or more occurrences of the +specified patterns. Example: The pattern +.Ic \&*(foo\&|bar) +matches the strings +.Dq , +.Dq foo , +.Dq bar , +.Dq foobarfoo , +etc. +.Sm off +.It Xo Ic \&+( Ar pattern Ic \&| No \ ...\ +.Ic \&| Ar pattern Ic \&) +.Xc +.Sm on +Matches any string of characters that matches one or more occurrences of the +specified patterns. Example: The pattern +.Ic \&+(foo\&|bar) +matches the strings +.Dq foo , +.Dq bar , +.Dq foobar , +etc. +.Sm off +.It Xo Ic \&?( Ar pattern Ic \&| No \ ...\ +.Ic \&| Ar pattern Ic \&) +.Xc +.Sm on +Matches the empty string or a string that matches one of the specified +patterns. Example: The pattern +.Ic \&?(foo\&|bar) +only matches the strings +.Dq , +.Dq foo +and +.Dq bar . +.Sm off +.It Xo Ic \&@( Ar pattern Ic \&| No \ ...\ +.Ic \&| Ar pattern Ic \&) +.Xc +.Sm on +Matches a string that matches one of the specified patterns. Example: The +pattern +.Ic \&@(foo\&|bar) +only matches the strings +.Dq foo +and +.Dq bar . +.Sm off +.It Xo Ic \&!( Ar pattern Ic \&| No \ ...\ +.Ic \&| Ar pattern Ic \&) +.Xc +.Sm on +Matches any string that does not match one of the specified patterns. Examples: +The pattern +.Ic \&!(foo\&|bar) +matches all strings except +.Dq foo +and +.Dq bar ; +the pattern +.Ic \&!(\&*) +matches no strings; the pattern +.Ic \&!(\&?)\&* +matches all strings (think about it). +.El +.Pp +Note that +.Nm pdksh +currently never matches +.Dq \&. +and +.Dq \&.\&. , +but the original +.Xr ksh , +Bourne +.Xr sh +and +.Xr bash +do, so this may have to change (too bad). +.Pp +Note that none of the above pattern elements match either a period +.Pq Sq \&. +at the start of a file name or a slash +.Pq Sq / , +even if they are explicitly used in a +.Ic \&[ Ns No .. Ns Ic \&] +sequence; also, the names +.Dq \&. +and +.Dq \&.\&. +are never matched, even by the pattern +.Dq \&.\&* . +.Pp +If the +.Ic markdirs +option is set, any directories that result from file name generation are marked +with a trailing +.Dq / . +.Pp +The POSIX character classes (i.e., +.Ic \&[\&: Ns Ar class-name Ns Ic \&:\&] +inside a +.Ic \&[ Ns No .. Ns Ic \&] +expression) are not yet implemented. +.Ss Input/output redirection +When a command is executed, its standard input, standard output and standard +error (file descriptors 0, 1 and 2, respectively) are normally inherited from +the shell. Three exceptions to this are commands in pipelines, for which +standard input and/or standard output are those set up by the pipeline, +asynchronous commands created when job control is disabled, for which standard +input is initially set to be from +.Pa /dev/null , +and commands for which any of the following redirections have been specified: +.Bl -tag -width Ds +.It Ic \&> Ar file +Standard output is redirected to +.Ar file . +If +.Ar file +does not exist, it is created; if it does exist, is a regular file and the +.Ic noclobber +option is set, an error occurs, otherwise the file is truncated. Note that this +means the command +.Ic cmd < foo > foo +will open +.Ar foo +for reading and then truncate it when it opens it for writing, before +.Ar cmd +gets a chance to actually read +.Ar foo . +.It Ic \&>\&| Ar file +Same as +.Ic \&> , +except the file is truncated, even if the +.Ic noclobber option is set. -.IP "\fB>>\fP \fIfile\fP" -same as \fB>\fP, except the file an existing file is appended to instead -of being truncated. Also, the file is opened in append mode, so writes -always go to the end of the file (see \fIopen\fP(2)). -.IP "\fB<\fP \fIfile\fP" -standard input is redirected from \fIfile\fP, which is opened for reading. -.IP "\fB<>\fP \fIfile\fP" -same as \fB<\fP, except the file is opened for reading and writing. -.IP "\fB<<\fP \fImarker\fP" -after reading the command line containing this kind of redirection (called a -here document), the shell copies lines from the command source into a temporary -file until a line matching \fImarker\fP is read. -When the command is executed, standard input is redirected from the temporary -file. -If \fImarker\fP contains no quoted characters, the contents of the -temporary file are processed as if enclosed in double quotes each time -the command is executed, so parameter, command and arithmetic substitutions -are performed, along with backslash (\fB\e\fP) escapes for -\fB$\fP, \fB`\fP, \fB\e\fP and \fB\enewline\fP. -If multiple here documents are used on the same command line, they are -saved in order. -.IP "\fB<<-\fP \fImarker\fP" -same as \fB<<\fP, except leading tabs are stripped from lines in the -here document. -.IP "\fB<&\fP \fIfd\fP" -standard input is duplicated from file descriptor \fIfd\fP. -\fIfd\fP can be a single digit, indicating the number of an existing -file descriptor, the letter \fBp\fP, indicating the file descriptor -associated with the output of the current co-process, or -the character \fB\-\fP, indicating standard input is to be closed. -.IP "\fB>&\fP \fIfd\fP" -same as \fB<&\fP, except the operation is done on standard output. -.PP -In any of the above redirections, the file descriptor that is redirected -(\fIi.e.\fP, standard input or standard output) can be explicitly given by -preceding the redirection with a single digit. -Parameter, command and arithmetic substitutions, tilde substitutions and -(if the shell is interactive) file name generation are all performed -on the \fIfile\fP, \fImarker\fP and \fIfd\fP arguments of redirections. -Note however, that the results of any file name generation are only used -if a single file is matched; if multiple files match, the word with the -unexpanded file name generation characters is used. -Note that in restricted shells, redirections which can create files cannot -be used. -.PP +.It Ic \&>\&> Ar file +Same as +.Ic \&> , +except if +.Ar file +exists it is appended to instead of being truncated. Also, the file is opened +in append mode, so writes always go to the end of the file (see +.Fn open 2 ) . +.It Ic \&< Ar file +Standard input is redirected from +.Ar file , +which is opened for reading. +.It Ic \&<\&> Ar file +Same as +.Ic \&< , +except the file is opened for reading and writing. +.It Ic \&<\&< Ar marker +After reading the command line containing this kind of redirection (called a +.Dq here document ) , +the shell copies lines from the command source into a termpoary file until a +line matching +.Ar marker +is read. When the command is executed, standard input is redirected from the +temporary file. If +.Ar marker +contains no quoted characters, the contents of the temporary file are processed +as if enclosed in double quotes each time the command is executed, so +parameter, command and arithmetic substitutions are performed, along with +backslash +.Pq Sq \e +escapes for +.Dq \&$ , +.Dq ` , +.Dq \e , +and +.Dq \enewline . +If multiple here documents are used on the same command line, they are saved in +order. +.It Ic \&<\&<\&- Ar marker +Same as +.Ic \&<\&< , +except leading tabs are stripped from lines in the here document. +.It Ic \&<\&& Ar fd +Standard input is duplicated from file descriptor +.Ar fd . +.Ar fd +can be a single digit, indicating the number of an existing file descriptor; +the letter +.Dq p , +indicating the file descriptor associated with the output of the current +co-process; or the character +.Dq \&- , +indicating standard input is to be closed. +.It Ic \&>\&& Ar fd +Same as +.Ic \&<\&& , +except the operation is done on standard output. +.El +.Pp +In any of the above redirections, the file descriptor that is redirected (i.e., +standard input or standard output) can be explicitly given by preceding the +redirection with a single digit. Parameter, command and arithmetic +substitutions, tilde substitutions and (if the shell is interative) +file name generation are all performed on the +.Ar file , +.Ar marker +and +.Ar fd +arguments of redirections. Note, however, that the results of any file name +generation are only used if a single file is matched; if multiple files match, +the word with the expanded file name generation characters is used. Note +that in restricted shells, redirections which can create files cannot be used. +.Pp For simple-commands, redirections may appear anywhere in the command, for -compound-commands (\fBif\fP statements, \fIetc.\fP), any redirections must -appear at the end. -Redirections are processed after pipelines are created and in the order they -are given, so -.RS -\fBcat /foo/bar 2>&1 > /dev/null | cat \-n\fP -.RE +compund-commands +.Po +.Ic if +statements, etc. +.Pc , +any redirections must appear at the end. Redirections are processed after +pipelines are created and in the order they are given, so +.Pp +.Ic cat /foo/bar 2\&>&1 \&> /dev/null \&| cat -n +.Pp will print an error with a line number prepended to it. -.\"}}} -.\"{{{ Arithmetic Expressions -.SS "Arithmetic Expressions" -Integer arithmetic expressions can be used -with the \fBlet\fP command, -inside \fB$((\fP..\fB))\fP expressions, -inside array references (\fIe.g.\fP, \fIname\fP\fB[\fP\fIexpr\fP\fB]\fP), -as numeric arguments to the \fBtest\fP command, -and as the value of an assignment to an integer parameter. -.PP -Expression may contain alpha-numeric parameter identifiers, array -references, and integer constants and may be combined with the -following C operators (listed and grouped in increasing order of precedence). -.TP +.Ss Arithmetic expressions +Integer arithmetic expressions can be used with the +.Ic let +command, inside +.Ic $(( Ns No .. Ns Ic )) +expressions, inside array references (e.g., +.Sm off +.Ar name Ic \&[ Ar expr Ic \&] ) , +.Sm on +as numeric arguments to the +.Ic test +command, and as the value of an assignment to an integer parameter. +.Pp +Expressions may contain alpha-numeric parameter identifiers, array references, +and integer constants and may be combined with the following C operators +(listed and grouped in increasing order of precedence): +.Pp Unary operators: -\fB+ \- ! ~ ++ --\fP -.TP +.Bl -item -offset indent -compact +.It +.Ic \&+ \&- \&! \&~ \&+\&+ \&-\&- +.El +.Pp Binary operators: -\fB,\fP -.br -\fB= *= /= %= += \-= <<= >>= &= ^= |=\fP -.br -\fB||\fP -.br -\fB&&\fP -.br -\fB|\fP -.br -\fB^\fP -.br -\fB&\fP -.br -\fB== !=\fP -.br -\fB< <= >= >\fP -.br -\fB<< >>\fP -.br -\fB+ \-\fP -.br -\fB* / %\fP -.TP -Ternary operator: -\fB?:\fP (precedence is immediately higher than assignment) -.TP +.Bl -item -offset indent -compact +.It +.Ic \&, +.It +.Ic = \&*= /= %= \&+= \&-= \&<\&<= +.Ic \&>\&>= \&&= ^= \&|= +.It +.Ic \&|\&| +.It +.Ic \&&\&& +.It +.Ic \&| +.It +.Ic ^ +.It +.Ic \&& +.It +.Ic == \&!= +.It +.Ic \&< \&<= \&>= \&> +.It +.Ic \&<\&< \&>\&> +.It +.Ic \&+ \&- +.It +.Ic \&* / % +.El +.Pp +Ternary operators: +.Bl -item -offset indent -compact +.It +.Ic \&?\&: +(precedence is immediately higher than assignment) +.El +.Pp Grouping operators: -\fB( )\fP -.PP +.Bl -item -offset indent -compact +.It +.Ic \&( \&) +.El +.Pp Integer constants may be specified with arbitrary bases using the notation -\fIbase\fP\fB#\fP\fInumber\fP, where \fIbase\fP is a decimal integer specifying -the base, and \fInumber\fP is a number in the specified base. -.LP +.Ar base Ns Ic \&# Ns Ar number , +where +.Ar base +is a decimal integer specifying the base, and +.Ar number +is a number in the specified base. +.Pp The operators are evaluated as follows: -.RS -.IP "unary \fB+\fP" -result is the argument (included for completeness). -.IP "unary \fB\-\fP" -negation. -.IP "\fB!\fP" -logical not; the result is 1 if argument is zero, 0 if not. -.IP "\fB~\fP" -arithmetic (bit-wise) not. -.IP "\fB++\fP" -increment; must be applied to a parameter (not a literal or other -expression) - the parameter is incremented by 1. -When used as a prefix operator, the result is the incremented value of -the parameter, when used as a postfix operator, the result is the -original value of the parameter. -.IP "\fB++\fP" -similar to \fB++\fP, except the paramter is decremented by 1. -.IP "\fB,\fP" -separates two arithmetic expressions; the left hand side is evaluated first, -then the right. The result is value of the expression on the right hand side. -.IP "\fB=\fP" -assignment; variable on the left is set to the value on the right. -.IP "\fB*= /= %= += \-= <<= >>= &= ^= |=\fP" -assignment operators; \fI<var> <op>\fP\fB=\fP \fI<expr>\fP is the same as -\fI<var>\fP \fB=\fP \fI<var> <op>\fP \fB(\fP \fI<expr>\fP \fB)\fP. -.IP "\fB||\fP" -logical or; the result is 1 if either argument is non-zero, 0 if not. -The right argument is evaluated only if the left argument is zero. -.IP "\fB&&\fP" -logical and; the result is 1 if both arguments are non-zero, 0 if not. -The right argument is evaluated only if the left argument is non-zero. -.IP "\fB|\fP" -arithmetic (bit-wise) or. -.IP "\fB^\fP" -arithmetic (bit-wise) exclusive-or. -.IP "\fB&\fP" -arithmetic (bit-wise) and. -.IP "\fB==\fP" -equal; the result is 1 if both arguments are equal, 0 if not. -.IP "\fB!=\fP" -not equal; the result is 0 if both arguments are equal, 1 if not. -.IP "\fB<\fP" -less than; the result is 1 if the left argument is less than the right, -0 if not. -.IP "\fB<= >= >\fP" -less than or equal, greater than or equal, greater than. See <. -.IP "\fB<< >>\fP" -shift left (right); the result is the left argument with its bits shifted -left (right) by the amount given in the right argument. -.IP "\fB+ - * /\fP" -addition, subtraction, multiplication, and division. -.IP "\fB%\fP" -remainder; the result is the remainder of the division of the left argument -by the right. The sign of the result is unspecified if either argument -is negative. -.IP "\fI<arg1>\fP \fB?\fP \fI<arg2>\fP \fB:\fP \fI<arg3>\fP" -if \fI<arg1>\fP is non-zero, the result is \fI<arg2>\fP, -otherwise \fI<arg3>\fP. -.RE -.\"}}} -.\"{{{ Co-Processes -.SS "Co-Processes" -A co-process, which is a pipeline created with the \fB|&\fP operator, -is an asynchronous process that the shell can both write to -(using \fBprint \-p\fP) and read from (using \fBread \-p\fP). -The input and output of the co-process can also be manipulated -using \fB>&p\fP and \fB<&p\fP redirections, respectively. -Once a co-process has been started, another can't be started until -the co-process exits, or until the co-process input has been redirected using -an \fBexec \fP\fIn\fP\fB>&p\fP redirection. -If a co-process's input is redirected in this way, the next +.Pp +.Bl -tag -width Ds -offset indent +.It unary Ic \&+ +Result is the argument (included for completeness). +.It unary Ic \&- +Negation. +.It Ic \&! +Logical NOT; the result is 1 if argument is zero, 0 if not. +.It Ic \&~ +Arithmetic (bit-wise) NOT. +.It Ic \&+\&+ +Increment; must be applied to a parameter (not a literal or other expression). +The parameter is incremented by 1. When used as a prefix operator, the result +is the incremented value of the parameter; when used as a postfix operator, the +result is the original value of the parameter. +.It Ic \&-\&- +Similar to +.Ic \&+\&+ , +except the parameter is decremented by 1. +.It Ic \&, +Separates two arithmetic expressions; the left-hand side is evaluated first, +then the right. The result is the value of the expression on the right-hand +side. +.It Ic = +Assignment; variable on the left is set to the value on the right. +.It Xo Ic \&*= /= \&+= \&-= \&<\&<= +.Ic \&>\&>= \&&= ^= \&|= +.Xc +Assignment operators. +.Ao Ar var Ac +.Ao Ar op Ac = +.Ao Ar expr Ac +is the same as +.Ao Ar var Ac = +.Ao Ar var Ac +.Ao Ar op Ac +.Ic \&( +.Ao Ar expr Ac +.Ic \&) . +.It Ic \&|\&| +Logical OR; the result is 1 if either argument is non-zero, 0 if not. The right +argument is evaluated only if the left argument is zero. +.It Ic \&&\&& +Logical AND; the result is 1 if both arguments are non-zero, 0 if not. The +right argument is evaluated only if the left argument is non-zero. +.It Ic \&| +Arithmetic (bit-wise) OR. +.It Ic ^ +Arithmetic (bit-wise) XOR (exclusive-OR). +.It Ic \&& +Arithmetic (bit-wise) AND. +.It Ic == +Equal; the result is 1 if both arguments are equal, 0 if not. +.It Ic \&!= +Not equal; the result is 0 if both arguments are equal, 1 if not. +.It Ic \&< +Less than; the result is 1 if the left argument is less than the right, 0 if +not. +.It Ic \&<= \&>= \&> +Less than or equal, greater than or equal, greater than. See +.Ic \&< . +.It Ic \&<\&< \&>\&> +Shift left (right); the result is the left argument with its bits shifted left +(right) by the amount given in the right argument. +.It Ic \&+ \&- \&* / +Addition, subtraction, multiplication, and division. +.It Ic % +Remainder; the result is the remainder of the division of the left argument by +the right. The sign of the result is unspecified if either argument is +negative. +.It Xo Ao Ar arg1 Ac Ic \ \&? +.Ao Ar arg2 Ac Ic \ \&: Ao Ar arg3 Ac +.Xc +If +.Ao Ar arg1 Ac +is non-zero, the result is +.Ao Ar arg2 Ac , +otherwise +.Ao Ar arg3 Ac . +.El +.Ss Co-processes +A co-process, which is a pipeline created with the +.Ic \&|\&& +operator, is an asynchronous process that the shell can both write to (using +.Ic print -p ) +and read from (using +.Ic read -p ) . +The input and output of the co-process can also be manipulated using +.Ic \&>\&&p +and +.Ic \&<\&&p +redirections, respectively. Once a co-process has been started, another can't +be started until the co-process exits, or until the co-process's input has been +redirected using an +.Ic exec Ar n Ns Ic \&>\&&p +redirection. If a co-process's input is redirected in this way, the next co-process to be started will share the output with the first co-process, unless the output of the initial co-process has been redirected using an -\fBexec \fP\fIn\fP\fB<&p\fP redirection. -.PP +.Ic exec Ar n Ns Ic \&<\&&p +redirection. +.Pp Some notes concerning co-processes: -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu -the only way to close the co-process input (so the co-process reads -an end-of-file) is to redirect the input to a numbered file descriptor -and then close that file descriptor (\fIe.g.\fP, \fBexec 3>&p;exec 3>&-\fP). -.IP \ \ \(bu -in order for co-processes to share a common output, the shell must keep -the write portion of the output pipe open. -This means that end of file will not be detected until all co-processes -sharing the co-process output have exited (when they all exit, the shell -closes its copy of the pipe). -This can be avoided by redirecting the output to a numbered -file descriptor (as this also causes the shell to close its copy). -Note that this behaviour is slightly different from the original Korn shell -which closes its copy of the write portion of the co-process output when the -most recently started co-process (instead of when all sharing co-processes) -exits. -.IP \ \ \(bu -\fBprint \-p\fP will ignore SIGPIPE signals during writes -if the signal is not being trapped or ignored; the same is not true if -the co-process input has been duplicated to another file descriptor and -\fBprint \-u\fP\fIn\fP is used. -.nr PD \n(P2 -.\"}}} -.\"{{{ Functions -.SS "Functions" -Functions are defined using either Korn shell \fBfunction\fP \fIname\fP -syntax or the Bourne/POSIX shell \fIname\fP\fB()\fP syntax -(see below for the difference between the two forms). -Functions are like \fB.\fP-scripts in that they are executed in -the current environment, however, unlike \fB.\fP-scripts, shell arguments -(\fIi.e.\fP, positional parameters, \fB$1\fP, \fIetc.\fP) are never visible -inside them. -When the shell is determining the location of a command, functions are -searched after special built-in commands, and before regular and non-regular -built-ins, and before the \fBPATH\fP is searched. -.PP -An existing function may be deleted using \fBunset \-f\fP \fIfunction-name\fP. -A list of functions can be obtained using \fBtypeset +f\fP and the -function definitions can be listed using \fBtypeset \-f\fP. -\fBautoload\fP (which is an alias for \fBtypeset \-fu\fP) may be used to -create undefined functions; when an undefined function is executed, the -shell searches the path specified in the \fBFPATH\fP parameter for a file -with the same name as the function, which, if found is read and executed. -If after executing the file, the named function is found to be defined, the -function is executed, otherwise, the normal command search is continued -(\fIi.e.\fP, the shell searches the regular built-in command table -and \fBPATH\fP). -Note that if a command is not found using \fBPATH\fP, an attempt is -made to autoload a function using \fBFPATH\fP (this is an undocumented -feature of the original Korn shell). -.PP -Functions can have two attributes, trace and export, which can be set -with \fBtypeset \-ft\fP and \fBtypeset \-fx\fP, respectively. -When a traced function is executed, the shell's \fBxtrace\fP option is turned -on for the functions duration, otherwise the \fBxtrace\fP option is turned off. -The export attribute of functions is currently not used. In the original -Korn shell, exported functions are visible to shell scripts that are executed. -.PP +.Bl -bullet +.It +The only way to close the co-process's input (so the co-process reads an +end-of-file) is to redirect the input to a numbered file descriptor and then +close that file descriptor (e.g., +.Ic exec 3\&>\&&p\&; exec 3>\&>\&&\&- ) . +.It +In order for co-processes to share a common output, the shell must keep the +write portion of the output pipe open. This means that end-of-file will not be +detected until all co-processes sharing the co-process output have exited +(when they all exit, the shell closes its copy of the pipe). This can be +avoided by redirecting the output to a numbered file descriptor (as this also +causes the shell to close its copy). Note that this behaviour is slightly +different from the original Korn shell which closes its copy of the write +portion of the co-process output when the most recently started co-process +(instead of when all sharing co-processes) exits. +.It +.Ic print -p +will ignore +.Dv SIGPIPE +signals during writes if the signal is not being trapped or ignored; the same +is true if the co-process input has been duplicated to another file descriptor +and +.Ic print -u Ns Ar n +is used. +.El +.Ss Functions +Functions are defined using either Korn shell +.Ic function Ar name +syntax or the Bourne/POSIX shell +.Fn name +syntax (see below for the difference between the two forms). Functions are like +.Li .-scripts +in that they are executed in the current environment. Howeer, unlike +.Li .-scripts , +shell arguments (i.e., positional parameters $1, $2, etc.) are never visible +inside them. When the shell is determining the location of a command, functions +are searched after special built-in commands, and before regular and +non-regular built-ins, and before the +.Ev PATH +is searched. +.Pp +An existing function may be deleted using +.Ic unset Fl f Ar function-name . +A list of functions can be obtained using +.Ic typeset \&+f +and the function definitions can be listed using +.Ic typeset \&-f . +.Ic autoload +(which is an alias for +.Ic typeset \&-fu ) +may be used to create undefined functions; when an undefined function is +executed, the shell searches the path specified in the +.Ev FPATH +parameter for a file with the same name as the function, which, if found, is +read and executed. If after executing the file the named function is found to +be defined, the function is executed; otherwise, the normal command search is +continued (i.e., the shell searches the regular built-in command table and +.Ev PATH ) . +Note that if a command is not found using +.Ev PATH , +an attempt is made to autoload a function using +.Ev FPATH +(this is an undocumented feature of the original Korn shell). +.Pp +Functions can have two attributes, +.Dq trace +and +.Dq export , +which can be set with +.Ic typeset \&-ft +and +.Ic typeset \&-fx , +respectively. When a traced function is executed, the shell's +.Ic xtrace +option is turned on for the function's duration; otherwise, the +.Ic xtrace +option is turned off. The +.Dq export +attribute of functions is currently not used. In the original Korn shell, +exported functions are visible to shell scripts that are executed. +.Pp Since functions are executed in the current shell environment, parameter assignments made inside functions are visible after the function completes. -If this is not the desired effect, the \fBtypeset\fP command can be used -inside a function to create a local parameter. -Note that special parameters (\fIe.g.\fP, \fB$$\fP, \fB$!\fP) can't be -scoped in this way. -.PP -The exit status of a function is that of the last command executed in -the function. -A function can be made to finish immediately using the \fBreturn\fP command; -this may also be used to explicitly specify the exit status. -.PP -Functions defined with the \fBfunction\fP reserved word are -treated differently in the following ways from functions defined with -the \fB()\fP notation: -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu -the \fB$0\fP parameter is set to the name of the function -(Bourne-style functions leave \fB$0\fP untouched). -.IP \ \ \(bu -parameter assignments preceding function calls are not kept in -the shell environment -(executing Bourne-style functions will keep assignments). -.IP \ \ \(bu -\fBOPTIND\fP is saved/reset and restored on entry and exit from the function -so \fBgetopts\fP can be used properly both inside and outside the function -(Bourne-style functions leave \fBOPTIND\fP untouched, so using \fBgetopts\fP -inside a function interferes with using \fBgetopts\fP outside the function). -.nr PD \n(P2 -In the future, the following differences will also be added: -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu +If this is not the desired effect, the +.Ic typeset +command can be used inside a function to create a local parameter. Note that +special parameters (e.g., $$, $\&!) can't be scoped in this way. +.Pp +The exit status of a function is that of the last command executed in the +function. A function can be made to finish immediately using the +.Ic return +command; this may also be used to explicitly specify the exit status. +.Pp +Functions defined with the +.Ic function +reserved word are treated differently in the following ways from functions +defined with the +.Ic \&(\&) +notation: +.Bl -bullet +.It +The $0 parameter is set to the name of the function (Bourne-style functions +leave $0 untouched). +.It +Parameter assignments preceding function calls are not kept in the shell +environment (executing Bourne-style functions will keep assignments). +.It +.Ev OPTIND +is saved/reset and restored on entry and exit from the function so +.Ic getopts +can be used properly both inside and outside the function (Bourne-style +functions leave +.Dv OPTIND +untouched, so using +.Ic getopts +inside a function interferes with using +.Ic getopts +outside the function). In the future, the following differences will also be +added: +.Bl -bullet -offset indent +.It A separate trap/signal environment will be used during the execution of -functions. -This will mean that traps set inside a function will not affect the shell's -traps and signals that are not ignored in the shell (but may be trapped) will -have their default effect in a function. -.IP \ \ \(bu +functions. This will mean that traps set inside a function will not affect the +shell's traps and signals that are not ignored in the shell (but may be +trapped) will have their default effect in a function. +.It The EXIT trap, if set in a function, will be executed after the function returns. -.nr PD \n(P2 -.\"}}} -.\"{{{ POSIX mode -.SS "POSIX Mode" +.El +.El +.Ss POSIX mode The shell is intended to be POSIX compliant, however, in some cases, POSIX -behaviour is contrary either to the original Korn shell behaviour or to -user convenience. -How the shell behaves in these cases is determined by the state of -the posix option (\fBset \-o posix\fP) \(em if it is on, the POSIX behaviour -is followed, otherwise it is not. -The \fBposix\fP option is set automatically when the shell starts up -if the environment contains the \fBPOSIXLY_CORRECT\fP parameter. -(The shell can also be compiled so that it is in POSIX mode by default, -however this is usually not desirable). -.PP -The following is a list of things that are affected by the state of -the \fBposix\fP option: -.nr P2 \n(PD -.nr PD 0 -.IP \ \ \(bu -\fB\e"\fP inside double quoted \fB`\fP..\fB`\fP command substitutions: -in posix mode, the \fB\e"\fP is interpreted when the command is interpreted; -in non-posix mode, the backslash is stripped before the command substitution -is interpreted. For example, \fBecho "`echo \e"hi\e"`"\fP produces `"hi"' in -posix mode, `hi' in non-posix mode. To avoid problems, use the \fB$(...\fP) +behaviour is contrary either to the original Korn shell behaviour or to user +convenience. How the shell behaves in these cases is determined by the state +of the +.Ic posix +option +.Pq Ic set Fl o Ic posix . +If it is on, the POSIX behaviour is followed, otherwise it is not. The +.Ic posix +option is set automatically when the shell starts up if the environment +contains the +.Dv POSIXLY_CORRECT +parameter. (The shell can also be compiled so that it is in POSIX mode by +default, however this is usually not desirable). +.Pp +The following is a list of things that are affected by the state of the +.Ic posix +option: +.Bl -bullet +.It +Occurrences of +.Ic \e\&" +inside double quoted +.Ic `\&.\&.` +command substitutions. In POSIX mode, the +.Ic \e\&" +is interpreted when the command is interpreted; in non-POSIX mode, the +backslash is stripped before the command substitution is interpreted. For +example, +.Ic echo \&"`echo \e\&"hi\e\&"`\&" +produces +.Dq \&"hi\&" +in POSIX mode, +.Dq hi +in non-POSIX mode. To avoid problems, use the +.Ic $(...) form of command substitution. -.IP \ \ \(bu -\fBkill \-l\fP output: in posix mode, signal names are listed one a single line; -in non-posix mode, signal numbers, names and descriptions are printed in -columns. -In future, a new option (\fB\-v\fP perhaps) will be added to distinguish -the two behaviours. -.IP \ \ \(bu -\fBfg\fP exit status: in posix mode, the exit status is 0 if no errors occur; -in non-posix mode, the exit status is that of the last foregrounded job. -.IP \ \ \(bu -\fBgetopts\fP: in posix mode, options must start with a \fB\-\fP; in non-posix -mode, options can start with either \fB\-\fP or \fB+\fP. -.IP \ \ \(bu -brace expansion (also known as alternation): in posix mode, brace expansion -is disabled; in non-posix mode, brace expansion enabled. -Note that \fBset \-o posix\fP (or setting the \fBPOSIXLY_CORRECT\fP parameter) -automatically turns the \fBbraceexpand\fP option off, however it can be -explicitly turned on later. -.IP \ \ \(bu -\fBset \-\fP: in posix mode, this does not clear the \fBverbose\fP or -\fBxtrace\fP options; in non-posix mode, it does. -.IP \ \ \(bu -\fBset\fP exit status: in posix mode, the exit status of set is 0 -if there are no errors; in non-posix mode, the exit status is that of -any command substitutions performed in generating the set command. -For example, `\fBset \-\- `false`; echo $?\fP' prints 0 in posix mode, -1 in non-posix mode. This construct is used in most shell scripts that -use the old \fIgetopt\fP(1) command. -.IP \ \ \(bu -argument expansion of \fBalias\fP, \fBexport\fP, \fBreadonly\fP, and -\fBtypeset\fP commands: in posix mode, normal argument expansion done; -in non-posix mode, field splitting, file globing, brace expansion and -(normal) tilde expansion are turned off, and assignment tilde expansion -is turned on. -.IP \ \ \(bu -signal specification: in posix mode, signals can be specified as digits only -if signal numbers match POSIX values (\fIi.e.\fP, HUP=1, INT=2, QUIT=3, ABRT=6, -KILL=9, ALRM=14, and TERM=15); in non-posix mode, signals can be always digits. -.IP \ \ \(bu -alias expansion: in posix mode, alias expansion is only carried out when -reading command words; in non-posix mode, alias expansion is carried out -on any word following an alias that ended in a space. -For example, the following for loop -.RS -.ft B -alias a='for ' i='j' -.br -a i in 1 2; do echo i=$i j=$j; done -.ft P -.RE -uses parameter \fBi\fP in posix mode, \fBj\fP in non-posix mode. -.IP \ \ \(bu -test: in posix mode, the expression "\fB-t\fP" (preceded by -some number of "\fB!\fP" arguments) is always true as it is a non-zero length -string; in non-posix mode, it tests if file descriptor 1 is a tty (\fIi.e.\fP, -the \fIfd\fP argument to the \fB-t\fP test may be left out and defaults to 1). -.nr PD \n(P2 -.\"}}} -.\"{{{ Command Execution (built-in commands) -.SS "Command Execution" +.It +.Ic kill -l +output. In POSIX mode, signal names are listed one per line; in non-POSIX mode, +signal numbers, names and descriptions are printed in columns. In future, a new +option +.Po Fl v +\ perhaps +.Pc +will be added to distinguish the two behaviours. +.It +.Ic fg +exit status. In POSIX mode, the exit status is 0 if no errors occur; in +non-POSIX mode, the exit status is that of the last foregrounded job. +.It +.Ic getopts . +In POSIX mode, options must start with a +.Dq \&- ; +in non-POSIX mode, options can start with either +.Dq \&- +or +.Dq \&+ . +.It +Brace expansion (also known as alternation). In POSIX mode, brace expansion is +disabled; in non-POSIX mode, brace expansion is enabled. Note that +.Ic set Fl o Ic posix +(or setting the +.Ev POSIXLY_CORRECT +parameter) automatically turns the +.Ic braceexpand +option off, however, it can be explicitly turned on later. +.It +.Ic set \&- . +In POSIX mode, this does not clear the +.Ic verbose +or +.Ic xtrace +options; in non-POSIX mode, it does. +.It +.Ic set +exit status. In POSIX mode, the exit status of +.Ic set +is 0 if there are no errors; in non-POSIX mode, the exit status is that of any +command substitutions performed in generating the +.Ic set +command. For example, +.Ic set \&-\&- `false`; echo $? +prints 0 in POSIX mode, 1 in non-POSIX mode. This construct is used in most +shell scripts that use the old +.Xr getopt 1 +command. +.It +Argument expansion of +.Ic alias , +.Ic export , +.Ic readonly , +and +.Ic typeset +commands. In POSIX mode, normal argument expansion is done; in non-POSIX mode, +field splitting, file globbing, brace expansion, and (normal) tilde expansion +are turned off, while assignment tilde expansion is turned on. +.It +Signal specification. In POSIX mode, signals can be specified as digits, only +if signal numbers match POSIX values (i.e., HUP=1, INT=2, QUIT=3, ABRT=6, +KILL=9, ALRM=14, and TERM=15); in non-POSIX mode, signals can always be digits. +.It +Alias expansion. In POSIX mode, alias expansion is only carried out when +reading command words; in non-POSIX mode, alias expansion is carried out on any +word following an alias that ended in a space. For example, the following +.Ic for +loop +.Pp +.Bl -item -offset indent -compact +.It +.Ic alias a='for ' i='j' +.It +.Ic a i in 1 2; do echo i=$i j=$j; done +.El +.Pp +uses parameter +.Ic i +in POSIX mode, +.Ic j +in non-POSIX mode. +.It +Test. In POSIX mode, the expression +.Dq Fl t +(preceded by some number of +.Dq Ic \&! +arguments) is always true as it is a non-zero length string; in non-POSIX mode, +it tests if file descriptor 1 is a tty (i.e., the +.Ar fd +argument to the +.Fl t +test may be left out and defaults to 1). +.El +.Ss Command execution After evaluation of command line arguments, redirections and parameter -assignments, the type of command is determined: a special built-in, -a function, a regular built-in or the name of a file to execute found -using the \fBPATH\fP parameter. -The checks are made in the above order. -Special built-in commands differ from other commands in that -the \fBPATH\fP parameter is not used to find them, an error -during their execution can cause a non-interactive shell to exit and -parameter assignments that are specified before the command are -kept after the command completes. -Just to confuse things, if the posix option is turned off (see \fBset\fP -command below) some special commands are very special in that -no field splitting, file globing, brace expansion nor tilde expansion -is preformed on arguments that look like assignments. -Regular built-in commands are different only in that the \fBPATH\fP +assignments, the type of command is determined; a special built-in, a function, +a regular built-in, or the name of a file to execute found using the +.Ev PATH +parameter. The checks are made in the above order. Special built-in commands +differ from other commands in that the +.Ev PATH +parameter is not used to find them, and an error during their execution can +cause a non-interactive shell to exit and parameter assignments that are +specified before the command are kept after the command completes. Just to +confuse things, if the +.Ic posix +option is turned off (see +.Ic set +command below), some special commands are very special in that no field +splitting, file globbing, brace expansion, nor tilde expansion is performed +on arguments that look like assignments. Regular built-in commands are +different only in that the +.Ev PATH parameter is not used to find them. -.PP +.Pp The original ksh and POSIX differ somewhat in which commands are considered special or regular: -.IP "POSIX special commands" -.TS -lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB . -\&. continue exit return trap -: eval export set unset -break exec readonly shift -.TE -.IP "Additional ksh special commands" -.TS -lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB . -builtin times typeset -.TE -.IP "Very special commands (non-posix mode)" -.TS -lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB . -alias readonly set typeset -.TE -.IP "POSIX regular commands" -.TS -lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB . -alias command fg kill umask -bg false getopts read unalias -cd fc jobs true wait -.TE -.IP "Additional ksh regular commands" -.TS -lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB lw(8m)fB . -[ let pwd ulimit -echo print test whence -.TE -.PP -In the future, the additional ksh special and regular commands may -be treated differently from the POSIX special and regular commands. -.PP +.Pp +POSIX special commands +.Pp +.Ic \&. , \&: , break , continue , +.Ic eval , exec , exit , export , +.Ic readonly , return , set , shift , +.Ic trap , unset +.Pp +Additional ksh special commands +.Pp +.Ic builtin , times , typeset +.Pp +Very special commands (non-POSIX mode) +.Pp +.Ic alias , readonly , set , typset +.Pp +POSIX regular commands +.Pp +.Ic alias , bg , cd , command , +.Ic false , fc , fg , getopts , +.Ic jobs , kill , read , true , +.Ic umask , unalias , wait +.Pp +Additional ksh regular commands +.Pp +.Ic \&[ , echo , let , print , +.Ic pwd , test , ulimit , whence +.Pp +In the future, the additional ksh special and regular commands may be treated +differently from the POSIX special and regular commands. +.Pp Once the type of the command has been determined, any command line parameter assignments are performed and exported for the duration of the command. -.PP -The following describes the special and regular built-in commands: -.\"{{{ . file [ arg1 ... ] -.IP "\fB\&.\fP \fIfile\fP [\fIarg1\fP ...]" -Execute the commands in \fIfile\fP in the current environment. -The file is searched for in the directories of \fBPATH\fP. -If arguments are given, the positional parameters may be used to -access them while \fIfile\fP is being executed. -If no arguments are given, the positional parameters are those of the -environment the command is used in. -.\"}}} -.\"{{{ : [ ... ] -.IP "\fB:\fP [ ... ]" -The null command. -Exit status is set to zero. -.\"}}} -.\"{{{ alias [ -d | +-t [ -r ] ] [+-px] [+-] [name1[=value1] ...] -.IP "\fBalias\fP [ \fB\-d\fP | \fB\(+-t\fP [\fB\-r\fP] ] [\fB\(+-px\fP] [\fB\(+-\fP] [\fIname1\fP[\fB=\fP\fIvalue1\fP] ...]" -Without arguments, \fBalias\fP lists all aliases. -For any name without a value, the existing alias is listed. -Any name with a value defines an alias (see Aliases above). -.sp -When listing aliases, one of two formats is used: -normally, aliases are listed as \fIname\fP\fB=\fP\fIvalue\fP, where -\fIvalue\fP is quoted; if options were preceded with \fB+\fP -or a lone \fB+\fP is given on the command line, only \fIname\fP -is printed. -In addition, if the \fB\-p\fP option is used, each alias -is prefixed with the string "\fBalias\fP\ ". -.sp -The \fB\-x\fP option sets (\fB+x\fP clears) the export attribute of an alias, -or, if no names are given, lists the aliases with the export attribute -(exporting an alias has no effect). -.sp -The \fB\-x\fP option sets the export attribute of an alias, or, if no -names are given, lists the aliases with the export attribute -(exporting an alias currently has no effect). -.sp -The \fB\-t\fP option indicates that tracked aliases are to be listed/set -(values specified on the command line are ignored for tracked aliases). -The \fB\-r\fP option indicates that all tracked aliases are to be reset. -.sp -The \fB\-d\fP causes directory aliases, which are used in tilde expansion, -to be listed or set (see Tilde Expansion above). -.\"}}} -.\"{{{ bg [job ...] -.IP "\fBbg\fP [\fIjob\fP ...]" -Resume the specified stopped job(s) in the background. -If no jobs are specified, \fB%+\fP is assumed. -This command is only available on systems which support job control. -See Job Control below for more information. -.\"}}} -.\"{{{ bind [-l] [-m] [key[=editing-command] ...] -.IP "\fBbind\fP [\fB\-m\fP] [\fIkey\fP[\fB=\fP\fIediting-command\fP] ...]" -Set or view the current emacs command editing key bindings/macros. -See Emacs Interactive Input Line Editing below for a complete description. -.\"}}} -.\"{{{ break [level] -.IP "\fBbreak\fP [\fIlevel\fP]" -\fBbreak\fP exits the \fIlevel\fPth inner most for, select, until, or while +.Pp +The following described the special and regular built-in commands: +.Bl -tag -width Ds +.It Ic \&. Ar file Op Ar arg1 ... +Execute the commands in +.Ar file +in the current environment. The file is searched for in the directories of +.Ev PATH . +If arguments are given, the positional parameters may be used to access them +while +.Ar file +is being executed. If no arguments are given, the positional parameters are +those of the environment the command is used in. +.It Ic \&: Op Ar ... +The null command. Exit status is set to zero. +.It Xo Ic alias No [\ -d\ |\ +-t\ [-r]\ ]\ [+-px]\ [+-] +.Sm off +.Op Ar name1 No [= Ar value1 No \&]\ \&.\&.\&. +.Sm on +.Xc +Without arguments, +.Ic alias +lists all aliases. For any name without a value, the existing alias is listed. +Any name with a value defines an alias (see +.Sx Aliases +above). +.Pp +When listing aliases, one of two formats is used. Normally, aliases are listed +as +.Ar name Ns No = Ar value , +where +.Ar value +is quoted. If options were preceded with +.Dq \&+ , +or a lone \&+ is given on the command line, only +.Ar name +is printed. In addition, if the +.Fl p +option is used, each alias is prefixed with the string +.Dq alias\ \& . +.Pp +The +.Fl x +option sets +.Po Ic \&+x +\ clears +.Pc +the export attribute of an alias, or, if no names are given, lists the aliases +with the export attribute (exporting an alias has no effect). +.Pp +The +.Fl t +option indicates that tracked aliases are to be listed/set (values specified on +the command line are ignored for tracked aliases). The +.Fl r +option indicates that all tracked aliases are to be reset. +.Pp +The +.Fl d +option causes directory aliases, which are used in tilde expansion, to be +listed or set (see +.Sx Tilde expansion +above). +.It Ic bg Op Ar job ... +Resume the specified stopped job(s) in the background. If no jobs are +specified, +.Ic %\&+ +is assumed. This command is only available on systems which support job +control (see +.Sx Job control +below for more information). +.It Xo Ic bind [ \&-m ] +.Sm off +.Oo Ar key No [= Ar editing-command No ]\ ... Oc +.Xc +.Sm on +Set or view the current emacs command editing key bindings/macros (see +.Sx Emacs interactive input line editing +below for a complete description). +.It Ic break Op Ar level +Exit the +.Ar level Ns th +inner-most +.Ic for , +.Ic select , +.Ic until , +or +.Ic while +loop. +.Ar level +defaults to 1. +.It Ic builtin Ar command Op Ar arg1 ... +Execute the built-in command +.Ar command . +.It Xo Ic cd Op Fl LP +.Op Ar dir +.Xc +Set the working directory to +.Ar dir . +If the parameter +.Ev CDPATH +is set, it lists the search path for the directory containing +.Ar dir . +A +.Dv NULL +path means the current directory. If +.Ar dir +is found in any component of the +.Ev CDPATH +search path other than the +.Dv NULL +path, the name of the new working directory will be written to standard output. +If +.Ar dir +is missing, the home directory +.Ev HOME +is used. If +.Ar dir +is +.Dq \&- , +the previous working directory is used (see +.Ev OLDPWD +parameter). If the +.Fl L +option (logical path) is used or if the +.Ic physical +option (see +.Ic set +command below) isn't set, references to +.Dq \&.\&. +in +.Ar dir +are relative to the path used to get to the directory. If the +.Fl P +option (physical path) is used or if the +.Ic physical +option is set, +.Dq \&.\&. +is relative to the filesystem directory tree. The +.Ev PWD +and +.Ev OLDPWD +parameters are updated to reflect the current and old working directory, +respectively. +.It Xo Ic cd Op Fl LP +.Ar old new +.Xc +The string +.Ar new +is substituted for +.Ar old +in the current directory, and the shell attempts to change to the new +directory. +.It Xo Ic command Op Fl pvV +.Ar cmd Op Ar arg1 ... +.Xc +If neither the +.Fl v +nor +.Fl V +options are given, +.Ar cmd +is executed exactly as if the +.Ic command +had not been specified, with two exceptions. First, +.Ar cmd +cannot be a shell function, and second, special built-in commands lose their +specialness (i.e., redirection and utility errors do not cause the shell to +exit, and command assignments are not permanent). If the +.Fl p +option is given, a default search path is used instead of the current value of +.Ev PATH +(the actual value of the default path is system dependent; on POSIXish systems, +it is the value returned by +.Ic getconf CS_PATH ) . +.Pp +If the +.Fl v +option is given, instead of executing +.Ar cmd , +information about what would be executed is given (and the same is done for +.Ar arg1 ... ) . +For special and regular built-in commands and functions, their names are simply +printed; for aliases, a command that defines them is printed; and for commands +found by searching the +.Ev PATH +parameter, the full path of the command is printed. If no command is found +(i.e., the path search fails), nothing is printed and +.Ic command +exits with a non-zero status. The +.Fl V +option is like the +.Fl v +option, except it is more verbose. +.It Ic continue Op Ar level +Jumps to the beginning of the +.Ar level Ns th +inner-most +.Ic for , +.Ic select , +.Ic until , +or +.Ic while loop. -\fIlevel\fP defaults to 1. -.\"}}} -.\"{{{ builtin command [arg1 ...] -.IP "\fBbuiltin\fP \fIcommand\fP [\fIarg1\fP ...]" -Execute the built-in command \fIcommand\fP. -.\"}}} -.\"{{{ cd [-LP] [dir] -.IP "\fBcd\fP [\fB\-LP\fP] [\fIdir\fP]" -Set the working directory to \fIdir\fP. If the parameter \fBCDPATH\fP -is set, it lists directories to search in for \fIdir\fP. -\fIdir\fP. An empty entry in the \fBCDPATH\fP entry means the current -directory. If a non-empty directory from \fBCDPATH\fP is used, the resulting -full path is printed to standard output. If \fIdir\fP is found in any -component of the \fBCDPATH\fP search path other than the null path the name -of the new working directory will be written to standard output. If -\fIdir\fP is missing, the home directory \fB$HOME\fP is used. If \fIdir\fP -is \fB\-\fP, the previous working directory is used (see OLDPWD parameter). -If \fB\-L\fP option (logical path) is used or if the \fBphysical\fP option -(see \fBset\fP command below) isn't set, references to \fB..\fP in \fIdir\fP -are relative to the path used get to the directory. -If \fB\-P\fP option (physical path) is used or if the \fBphysical\fP option -is set, \fB..\fP is relative to the filesystem directory tree. -The \fBPWD\fP and \fBOLDPWD\fP parameters are updated to reflect the -current and old wording directory, respectively. -.\"}}} -.\"{{{ cd [-LP] old new -.IP "\fBcd\fP [\fB\-LP\fP] \fIold new\fP" -The string \fInew\fP is substituted for \fIold\fP in the current -directory, and the shell attempts to change to the new directory. -.\"}}} -.\"{{{ command [ -pvV ] cmd [arg1 ...] -.IP "\fBcommand\fP [\fB\-pvV\fP] \fIcmd\fP [\fIarg1\fP ...]" -If neither the \fB\-v\fP nor \fB\-V\fP options are given, -\fIcmd\fP -is executed exactly as if the \fBcommand\fP had not been specified, -with two exceptions: first, \fIcmd\fP cannot be a shell function, and -second, special built-in commands lose their specialness (\fIi.e.\fP, -redirection and utility errors do not cause the shell to exit, and command -assignments are not permanent). -If the \fB\-p\fP option is given, a default search path is used instead of -the current value of \fBPATH\fP (the actual value of the default path is -system dependent: on POSIXish systems, it is the value returned by -.ce -\fBgetconf CS_PATH\fP -). -.sp -If the \fB\-v\fP option is given, instead of executing \fIcmd\fP, information -about what would be executed is given (and the same is done for -\fIarg1\fP ...): -for special and regular built-in commands and functions, -their names are simply printed, -for aliases, a command that defines them is printed, -and for commands found by searching the \fBPATH\fP parameter, -the full path of the command is printed. -If no command is be found, (\fIi.e.\fP, the path search fails), nothing -is printed and \fBcommand\fP exits with a non-zero status. -The \fB\-V\fP option is like the \fB\-v\fP option, except it is more verbose. -.\"}}} -.\"{{{ continue [levels] -.IP "\fBcontinue\fP [\fIlevels\fP]" -\fBcontinue\fP jumps to the beginning of the \fIlevel\fPth inner most for, -select, until, or while loop. -\fIlevel\fP defaults to 1. -.\"}}} -.\"{{{ echo [-neE] [arg ...] -.IP "\fBecho\fP [\fB\-neE\fP] [\fIarg\fP ...]" -Prints its arguments (separated by spaces) followed by a newline, to -standard out. -The newline is suppressed if any of the arguments contain the backslash -sequence \fB\ec\fP. -See \fBprint\fP command below for a list of other backslash sequences -that are recognized. -.sp -The options are provided for compatibility with BSD shell scripts: -\fB\-n\fP suppresses the trailing newline, \fB\-e\fP enables backslash -interpretation (a no-op, since this is normally done), and \fB\-E\fP which -suppresses backslash interpretation. -.\"}}} -.\"{{{ eval command ... -.IP "\fBeval\fP \fIcommand ...\fP" -The arguments are concatenated (with spaces between them) to form -a single string which the shell then parses and executes -in the current environment. -.\"}}} -.\"{{{ exec [command [arg ...]] -.IP "\fBexec\fP [\fIcommand\fP [\fIarg\fP ...]]" +.Ar level +defaults to 1. +.It Xo Ic echo Op Fl neE +.Op Ar arg ... +.Xc +Prints its arguments (separated by spaces) followed by a newline, to the +standard output. The newline is suppressed if any of the arguments contain the +backslash sequence +.Dq \ec . +See the +.Ic print +command below for a list of other backslash sequences that are recognized. +.Pp +The options are provided for compatibility with +.Bx +shell scripts. The +.Fl n +option suppresses the trailing newline, +.Fl e +enables backslash interpretation (a no-op, since this is normally done), and +.Fl E +which suppresses backslash interpretation. +.It Ic eval Ar command ... +The arguments are concatenated (with spaces between them) to form a single +string which the shell then parses and executes in the current environment. +.It Xo Ic exec +.Op Ar command Op Ar arg ... +.Xc The command is executed without forking, replacing the shell process. -.sp -If no arguments are given, any IO redirection is permanent and the shell -is not replaced. -Any file descriptors greater than 2 which are opened or \fIdup\fP(2)-ed -in this way are not -made available to other executed commands (\fIi.e.\fP, -commands that are not built-in to the shell). -Note that the Bourne shell differs here: it does pass these -file descriptors on. -.\"}}} -.\"{{{ exit [status] -.IP "\fBexit\fP [\fIstatus\fP]" -The shell exits with the specified exit status. -If \fIstatus\fP is not specified, the exit status is the current -value of the \fB?\fP parameter. -.\"}}} -.\"{{{ export [-p] [parameter[=value] ...] -.IP "\fBexport\fP [\fB\-p\fP] [\fIparameter\fP[\fB=\fP\fIvalue\fP]] ..." -Sets the export attribute of the named parameters. -Exported parameters are passed in the environment to executed commands. -If values are specified, the named parameters also assigned. -.sp +.Pp +If no arguments are given, and I/O redirection is permanent and the shell is +not replaced. Any file descriptors greater than 2 which are opened or +.Xr dup 2 Ns 'd +in this way are not made available to other executed commands (i.e., commands +that are not built-in to the shell). Note that the Bourne shell differs here; +it does pass these file descriptors on. +.It Ic exit Op Ar status +The shell exits with the specified exit status. If +.Ar status +is not specified, the exit status is the current value of the +.Ic \&? +parameter. +.It Xo Ic export Op Fl p +.Op Ar parameter Ns Op \&= Ns Ar value +.Xc +Sets the export attribute of the named parameters. Exported parameters are +passed in the environment to executed commands. If values are specified, the +named parameters are also assigned. +.Pp If no parameters are specified, the names of all parameters with the export -attribute are printed one per line, unless the \fB\-p\fP option is used, -in which case \fBexport\fP commands defining all exported -parameters, including their values, are printed. -.\"}}} -.\"{{{ false -.IP "\fBfalse\fP" +attribute are printed one per line, unless the +.Fl p +option is used, in which case +.Ic export +commands defining all exported parameters, including their values, are printed. +.It Ic false A command that exits with a non-zero status. -.\"}}} -.\"{{{ fc [-e editor | -l [-n]] [-r] [first [ last ]] -.IP "\fBfc\fP [\fB\-e\fP \fIeditor\fP | \fB\-l\fP [\fB\-n\fP]] [\fB\-r\fP] [\fIfirst\fP [\fIlast\fP]]" -\fIfirst\fP and \fIlast\fP select commands from the history. -Commands can be selected by -history number, or a string specifying the most recent command starting -with that string. The \fB\-l\fP option lists the command on stdout, -and \fB\-n\fP inhibits the default command numbers. The \fB\-r\fP -option reverses the order of the list. Without \fB\-l\fP, the selected -commands are edited by the editor specified with the \fB\-e\fP -option, or if no \fB\-e\fP is specified, the editor specified by the -\fBFCEDIT\fP parameter (if this parameter is not set, \fB/bin/ed\fP is used), -and then executed by the shell. -.\"}}} -.\"{{{ fc [-e - | -s] [-g] [old=new] [prefix] -.IP "\fBfc\fP [\fB\-e \-\fP | \fB\-s\fP] [\fB\-g\fP] [\fIold\fP\fB=\fP\fInew\fP] [\fIprefix\fP]" +.It Xo Ic fc No [-e\ editor\ |\ -l\ [-n]]\ [-r] +.Op Ar first Op Ar last +.Xc +.Ar first +and +.Ar last +select commands from the history. Commands can be selected by history number +or a string specifying the most recent command starting with that string. The +.Fl l +option lists the command on stdout, and +.Fl n +inhibits the default command numbers. The +.Fl r +option reverses the order of the list. Without +.Fl l , +the selected commands are edited by the editor specified with the +.Fl e +option, or if no +.Fl e +is specified, the editor specified by the +.Ev FCEDIT +parameter (if this parameter is not set, +.Pa /bin/ed +is used), and then executed by the shell. +.It Xo Ic fc No [-e\ -\ |\ -s]\ [-g]\ [old=new]\& +.Op Ar prefix +.Xc Re-execute the selected command (the previous command by default) after -performing the optional substitution of \fIold\fP with \fInew\fP. If -\fB\-g\fP is specified, all occurrences of \fIold\fP are replaced with -\fInew\fP. This command is usually accessed with the predefined alias -\fBr='fc \-e \-'\fP. -.\"}}} -.\"{{{ fg [job ...] -.IP "\fBfg\fP [\fIjob\fP ...]" -Resume the specified job(s) in the foreground. -If no jobs are specified, \fB%+\fP is assumed. -This command is only available on systems which support job control. -See Job Control below for more information. -.\"}}} -.\"{{{ getopts optstring name [arg ...] -.IP "\fBgetopts\fP \fIoptstring\fP \fIname\fP [\fIarg\fP ...]" -\fBgetopts\fP is used by shell procedures to parse the specified arguments -(or positional parameters, if no arguments are given) and to check for legal -options. -\fIoptstring\fP contains the option letters that -\fBgetopts\fP is to recognize. If a letter is followed by a colon, the -option is expected to have an argument. -Options that do not take arguments may be grouped in a single argument. -If an option takes an argument and the option character is not the last -character of the argument it is found in, the remainder of the argument -is taken to be the option's argument, otherwise, the next argument is -the option's argument. -.sp -Each time \fBgetopts\fP is invoked, it places the next option in -the shell parameter \fIname\fP and the index of the next argument to be -processed in the shell parameter \fBOPTIND\fP. -If the option was introduced with a \fB+\fP, the option placed in -\fIname\fP is prefixed with a \fB+\fP. -When an option requires an argument, \fBgetopts\fP places it in the -shell parameter \fBOPTARG\fP. -When an illegal option or a missing option argument is -encountered a question mark or a colon is placed in \fIname\fP -(indicating an illegal option or missing argument, respectively) -and \fBOPTARG\fP is set to the option character that caused the problem. -An error message is also printed to standard error if \fIoptstring\fP -does not begin with a colon. -.sp -When the end of the options is encountered, \fBgetopts\fP exits with a -non-zero exit status. -Options end at the first (non-option argument) argument that does not -start with a \-, or when a \fB\-\-\fP argument is encountered. -.sp -Option parsing can be reset by setting \fBOPTIND\fP to 1 (this is done -automatically whenever the shell or a shell procedure is invoked). -.sp -Warning: Changing the value of the shell parameter \fBOPTIND\fP to -a value other than 1, or parsing different sets of arguments without -resetting \fBOPTIND\fP may lead to unexpected results. -.\"}}} -.\"{{{ hash [-r] [name ...] -.IP "\fBhash\fP [\fB\-r\fP] [\fIname ...\fP]" -Without arguments, any hashed executable command pathnames are listed. -The \fB\-r\fP option causes all hashed commands to be removed -from the hash table. -Each \fIname\fP is searched as if it where a command name and added to the -hash table if it is an executable command. -.\"}}} -.\"{{{ jobs [-lpn] [job ...] -.IP "\fBjobs\fP [\fB\-lpn\fP] [\fIjob\fP ...]" -Display information about the specified jobs; if no jobs are specified, -all jobs are displayed. -The \fB\-n\fP option causes information to be displayed only for jobs -that have changed state since the last notification. -If the \fB\-l\fP option is used, the process-id of each process in a job -is also listed. -The \fB\-p\fP option causes only the process group of each job to be printed. -See Job Control below for the format of \fIjob\fP and the displayed job. -.\"}}} -.\"{{{ kill [-s signame | -signum | -signame] { job | pid | -pgrp } ... -.IP "\fBkill\fP [\fB\-s\fP \fIsigname\fP | \fB\-signum\fP | \fB\-signame\fP ] { \fIjob\fP | \fIpid\fP | \fB\-\fP\fIpgrp\fP } ..." -Send the specified signal to the specified jobs, process ids, or process groups. -If no signal is specified, the signal TERM is sent. -If a job is specified, the signal is sent to the job's process group. -See Job Control below for the format of \fIjob\fP. -.\"}}} -.\"{{{ kill -l [exit-status ...] -.IP "\fBkill \-l\fP [\fIexit-status\fP ...]" -Print the name of the signal that killed a process which exited with -the specified \fIexit-status\fPes. +performing the optional substitution of +.Ar old +with +.Ar new . +If +.Fl g +is specified, all occurrences of +.Ar old +are replaced with +.Ar new . +This command is usually accessed with the predefined +.Ic alias r='fx -e -' . +.It Ic fg Op Ar job ... +Resume the specified job(s) in the foreground. If no jobs are specified, +.Ic %\&+ +is assumed. This command is only available on systems which support job +control (see +.Sx Job control +below for more information). +.It Xo Ic getopts Ar optstring name +.Op Ar arg ... +.Xc +Used by shell procedures to parse the specified arguments (or positional +parameters, if no arguments are given) and to check for legal options. +.Ar optstring +contains the option letters that +.Ic getopts +is to recognize. If a letter is followed by a colon, the option is expected to +ahve an argument. Options that do not take arguments may be grouped in a single +argument. If an option takes an argument and the option character is not the +last character of the argument it is found in, the remainder of the argument is +taken to be the option's argument, otherwise, the next argument is the option's +argument. +.Pp +Each time +.Ic getopts +is invoked, it places the next option in the shell parameter +.Ar name +and the index of the next argument to be processed in the shell parameter +.Ev OPTIND . +If the option was introduced with a +.Dq \&+ , +the option places in +.Ar name +is prefixed with a +.Dq \&+ . +When an option requires an argument, +.Ic getopts +places it in the shell parameter +.Ev OPTARG . +When an illegal option or a missing option argument is encountered, a question +mark or a colon is placed in +.Ar name +(indicating an illegal option or missing argument, respectively) and +.Ev OPTAG +is set to the option character that caused the problem. An error message is +also printed to standard error if +.Ar optstring +does not being with a colon. +.Pp +When the end of the options is encountered, +.Ic getopts +exits with a non-zero exit status. Options end at the first (non-option +argument) argument that does not start with a +.Dq \&- , +or when a +.Dq \&-\&- +argument is encountered. +.Pp +Option parsing can be reset by setting +.Ev OPTIND +to 1 (this is done automatically whenever the shell or a shell procedure is +invoked). +.Pp +Warning: Changing the value of the shell parameter +.Ev OPTIND +to a value other than 1, or parsing different sets of arguments without +resetting +.Ev OPTIND +may lead to unexpected results. +.It Xo Ic hash Op Fl r +.Op Ar name ... +.Xc +Without arguments, any hashed executable command pathnames are listed. The +.Fl r +option causes all hashed commands to be removed from the hash table. Each +.Ar name +is searched as if it were a command name and added to the hash table if it is +an executable command. +.It Xo Ic jobs Op Fl lpn +.Op Ar job ... +.Xc +Display information about the specified job(s); if no jobs are specified, all +jobs are displayed. The +.Fl n +option causes information to be displayed only for jobs that have changed +state since the last notification. If the +.Fl l +option is used, the process ID of each process in a job is also listed. The +.Fl p +option causes only the process group of each job to be printed. See +.Sx Job control +below for the format of +.Ar job +and the displayed job. +.It Xo Ic kill No [-s\ signame\ |\ -signum\ |\ -signame\ ]\ {\ job\ |\ pid\ | +.No -pgrp\ }\ \&.\&.\&. +.Xc +Send the specified signal to the specified jobs, process IDs, or process +groups. If no signal is specified, the +.Dv TERM +signal is sent. If a job is specified, the signal is sent to the job's +process group. See +.Sx Job control +below for the format of +.Ar job . +.It Ic kill -l Op Ar exit-status ... +Print the name of the signal that killed a process which exited with the +specified +.Ar exit-status Ns es. If no arguments are specified, a list of all the signals, their numbers and a short description of them are printed. -.\"}}} -.\"{{{ let [expression ...] -.IP "\fBlet\fP [\fIexpression\fP ...]" -Each expression is evaluated, see Arithmetic Expressions above. -If all expressions are successfully evaluated, the exit status -is 0 (1) if the last expression evaluated to non-zero (zero). -If an error occurs during the parsing or evaluation of an expression, -the exit status is greater than 1. -Since expressions may need to be -quoted, \fB((\fP \fIexpr\fP \fB))\fP is syntactic sugar for \fBlet -"\fP\fIexpr\fP\fB"\fP. -.\"}}} -.\"{{{ print [-nprsun | -R [-en]] [argument ...] -.IP "\fBprint\fP [\fB\-nprsu\fP\fIn\fP | \fB\-R\fP [\fB\-en\fP]] [\fIargument ...\fP]" -\fBPrint\fP prints its arguments on the standard output, separated by -spaces, and terminated with a newline. The \fB\-n\fP option suppresses -the newline. By default, certain C escapes are translated. These -include \eb, \ef, \en, \er, \et, \ev, and \e0### (# is an octal digit, of -which there may be 0 to 3). -\ec is equivalent to using the \fB\-n\fP option. \e expansion may be -inhibited with the \fB\-r\fP option. -The \fB\-s\fP option prints to the history file instead of standard output, -the \fB\-u\fP option prints to file descriptor \fIn\fP (\fIn\fP -defaults to 1 if omitted), and the \fB\-p\fP option prints to the co-process -(see Co-Processes above). -.sp -The \fB\-R\fP option is used to emulate, to some degree, the BSD echo -command, which does not process \e sequences unless the \fB\-e\fP option -is given. -As above, the \fB\-n\fP option suppresses the trailing newline. -.\"}}} -.\"{{{ pwd [-LP] -.IP "\fBpwd\fP [\fB\-LP\fP]" -Print the present working directory. -If \fB\-L\fP option is used or if the \fBphysical\fP option -(see \fBset\fP command below) isn't set, the logical path is printed -(\fIi.e.\fP, the path used to \fBcd\fP to the current directory). -If \fB\-P\fP option (physical path) is used or if the \fBphysical\fP option -is set, the path determined from the filesystem (by following \fB..\fP +.It Ic let Op Ar expression ... +Each expression is evaluated (see +.Sx Arithmetic expressions +above). If all expressions are successfully evaluated, the exit status is 0 (1) +if the last expression evaluated to non-zero (zero). If an error occurs during +the parsing or evaluation of an expression, the exit status is greater than 1. +Since expressions may need to be quoted, +.Ic (( Ar expr Ic )) +is syntactic sugar for +.Ic let \&" Ns Ar expr Ns Ic \&" . +.It Xo Ic print Oo Fl nprsu Ns Ar n +.Li | Fl R No [-en] Oc [argument\ ...] +.Xc +.Ic print +prints its arguments on the standard output, separated by spaces, and +terminated with a newline. The +.Fl n +option suppresses the newline. By default, certain C escapes are translated. +These include +.Dq \eb , +.Dq \ef , +.Dq \en , +.Dq \er , +.Dq \et , +.Dq \ev , +and +.Dq \e0### +.Po +.Dq # +is an octal digit, of which there may be 0 to 3 +.Pc . +.Dq \ec +is equivalent to using the +.Fl n +option. +.Dq \e +expansion may be inhibited with the +.Fl r +option. The +.Fl s +option prints to the history file instead of standard output, the +.Fl u +option prints to file descriptor +.Ar n +.Po +.Ar n +defaults to 1 if omitted +.Pc , +and the +.Fl p +option prints to the co-process (see +.Sx Co-processes +above). +.Pp +The +.Fl R +option is used to emulate, to some degree, the +.Bx +.Xr echo +command, which does not process +.Dq \e +sequences unless the +.Fl e +option is given. As above, the +.Fl n +option suppresses the trailing newline. +.It Ic pwd Op Fl LP +Print the present working directory. If the +.Fl L +option is used or if the +.Ic physical +option (see +.Ic set +command below) isn't set, the logical path is printed (i.e., the path used to +.Ic cd +to the current directory). If the +.Fl P +option (physical path) is used or if the +.Ic physical +option is set, the path determined from the filesystem (by following +.Dq \&.\&. directories to the root directory) is printed. -.\"}}} -.\"{{{ read [-prsun] [parameter ...] -.IP "\fBread\fP [\fB\-prsu\fP\fIn\fP] [\fIparameter ...\fP]" -Reads a line of input from standard input, separate the line into fields using -the \fBIFS\fP parameter (see Substitution above), and assign each field to the -specified parameters. -If there are more parameters than fields, the extra parameters are set to null, +.It Xo Ic read Oo Fl prsu Ns Ar n +.Oc Op Ar parameter ... +.Xc +Reads a line of input from the standard input, separates the line into fields +using the +.Ev IFS +parameter (see +.Sx Substitution +above), and assigns each field to the specified parameters. If there are more +parameters than fields, the extra parameters are set to +.Dv NULL , or alternatively, if there are more fields than parameters, the last parameter -is assigned the remaining fields (inclusive of any separating spaces). -If no parameters are specified, the \fBREPLY\fP parameter is used. -If the input line ends in a backslash and the \fB\-r\fP option was not used, the -backslash and newline are stripped and more input is read. -If no input is read, \fBread\fP exits with a non-zero status. -.sp +is assigned the remaining fields (inclusive of any separating spaces). If no +parameters are specified, the +.Ev REPLY +parameter is used. If the input line ends in a backslash and the +.Fl r +option was not used, the backslash and the newline are stripped and more input +is read. If no input is read, +.Ic read +exits with a non-zero status. +.Pp The first parameter may have a question mark and a string appended to it, in which case the string is used as a prompt (printed to standard error before -any input is read) if the input is a tty -(\fIe.g.\fP, \fBread nfoo?'number of foos: '\fP). -.sp -The \fB\-u\fP\fIn\fP and \fB\-p\fP options cause input to be read -from file descriptor \fIn\fP or the current co-process (see Co-Processes above -for comments on this), respectively. -If the \fB\-s\fP option is used, input is saved to the history file. -.\"}}} -.\"{{{ readonly [-p] [parameter[=value] ...] -.IP "\fBreadonly\fP [\fB\-p\fP] [\fIparameter\fP[\fB=\fP\fIvalue\fP]] ..." -Sets the readonly attribute of the named parameters. If values are given, -parameters are set to them before setting the attribute. -Once a parameter is made readonly, it cannot be unset and its value cannot -be changed. -.sp -If no parameters are specified, the names of all parameters with the readonly -attribute are printed one per line, unless the \fB\-p\fP option is used, -in which case \fBreadonly\fP commands defining all readonly -parameters, including their values, are printed. -.\"}}} -.\"{{{ return [status] -.IP "\fBreturn\fP [\fIstatus\fP]" -Returns from a function or \fB.\fP script, with exit status \fIstatus\fP. -If no \fIstatus\fP is given, the exit status of the last executed command -is used. -If used outside of a function or \fB.\fP script, it has the same effect -as \fBexit\fP. -Note that pdksh treats both profile and \fB$ENV\fP files as \fB.\fP scripts, -while the original Korn shell only treats profiles as \fB.\fP scripts. -.\"}}} -.\"{{{ set [+-abCefhkmnpsuvxX] [+-o [option]] [+-A name] [--] [arg ...] -.IP "\fBset\fP [\fB\(+-abCefhkmnpsuvxX\fP] [\fB\(+-o\fP [\fIoption\fP]] [\fB\(+-A\fP \fIname\fP] [\fB\-\-\fP] [\fIarg\fP ...]" -The set command can be used to set (\fB\-\fP) or clear (\fB+\fP) shell options, -set the positional parameters, or set an array parameter. -Options can be changed using the \fB\(+-o\fP \fIoption\fP syntax, -where \fIoption\fP is the long name of an option, or using -the \fB\(+-\fP\fIletter\fP syntax, where \fIletter\fP is the -option's single letter name (not all options have a single letter name). +any input is read) if the input is a tty (e.g., +.Ic read nfoo?'number of foos: ' ) . +.Pp +The +.Fl u Ns Ar n +and +.Fl p +options cause input to be read from file descriptor +.Ar n +or the current co-process (see +.Sx Co-processes +above for comments on this), respectively. If the +.Fl s +option is used, input is saved to the history file. +.It Xo Ic readonly Op Fl p +.Sm off +.Oo Ar parameter Op = Ar value Oc \ ... +.Sm on +.Xc +Sets the read-only attribute of the named parameters. If values are given, +parameters are set to them before setting the attribute. Once a parameter is +made read-only, it cannot be unset and its value cannot be changed. +.Pp +If no parameters are specified, the names of all parameters with the read-only +attribute are printed one per line, unless the +.Fl p +option is used, in which case +.Ic readonly +commands defining all read-only parameters, including their values, are +printed. +.It Ic return Op Ar status +Returns from a function or +.Ic \&. +script, with exit status +.Ar status . +If no +.Ar status +is given, the exit status of the last executed command is used. If used +outside of a function or +.Ic \&. +script, it has the same effect as +.Ic exit . +Note that +.Nm pdksh +treats both profile and +.Ev ENV +files as +.Ic \&. +scripts, while the original Korn shell only treats profiles as +.Ic \&. +scripts. +.It Xo Ic set No [+-abCefhkmnpsuvxX]\ [+-o\ [option]]\ [+-A\ name]\ [--]\& +.Op Ar arg ... +.Xc +The set command can be used to set +.Pq Ic \&- +or clear +.Pq Ic \&+ +shell options, set the positional parameters, or set an array parameter. +Options can be changed using the +.Ic \&+ Ns Fl o Ar option +syntax, where +.Ar option +is the long name of an option, or using the +.Ic \&+\&- Ns Ar letter +syntax, where +.Ar letter +is the option's single letter name (not all options have a single letter name). The following table lists both option letters (if they exist) and long names -along with a description of what the option does. -.sp -.TS -expand; -afB lfB lw(3i). -\-A T{ -Sets the elements of the array parameter \fIname\fP to \fIarg\fP ...; -If \fB\-A\fP is used, the array is reset (\fIi.e.\fP, emptied) first; -if \fB+A\fP is used, the first N elements are set (where N is the number -of \fIarg\fPs), the rest are left untouched. -T} -\-a allexport T{ -all new parameters are created with the export attribute -T} -\-b notify T{ +along with a description of what the option does: +.Bl -tag -width 15n +.It Fl A +Sets the elements of the array parameter +.Ar name +to +.Ar arg ... . +If +.Fl A +is used, the array is reset (i.e., emptied) first; if +.Ic \&+A +is used, the first N elements are set (where N is the number of +.Ar arg Ns s ) , +the rest are left untouched. +.It Fl a Ic allexport +All new parameters are created with the export attribute. +.It Fl b Ic notify Print job notification messages asynchronously, instead of just before the -prompt. -Only used if job control is enabled (\fB\-m\fP). -T} -\-C noclobber T{ -Prevent \fB>\fP redirection from overwriting existing files (\fB>|\fP must -be used to force an overwrite). -T} -\-e errexit T{ -Exit (after executing the \fBERR\fP trap) as soon as an error occurs or -a command fails (\fIi.e.\fP, exits with a non-zero status). -This does not apply to commands whose exit status is explicitly tested by a -shell construct such as \fBif\fP, \fBuntil\fP, \fBwhile\fP, \fB&&\fP or -\fB||\fP statements. -T} -\-f noglob T{ +prompt. Only used if job control is enabled +.Pq Fl m . +.It Fl C Ic noclobber +Prevent +.Ic \&> +redirection from overwriting existing files +.Po +.Ic \&>\&| +must be used to force an overwrite +.Pc . +.It Fl e Ic errexit +Exit (after executing the +.Dv ERR +trap) as soon as an error occurs or a command fails (i.e., exits with a +non-zero status). This does not apply to commands whose exit status is +explicitly tested by a shell construct such as +.Ic if , +.Ic until , +.Ic while , +.Ic \&&\&& , +or +.Ic \&|\&| +statements. +.It Fl f Ic noglob Do not expand file name patterns. -T} -\-h trackall T{ -Create tracked aliases for all executed commands (see Aliases above). -On by default for non-interactive shells. -T} -\-i interactive T{ -Enable interactive mode \- this can only be set/unset when the shell is -invoked. -T} -\-k keyword T{ +.It Fl h Ic trackall +Create tracked aliases for all executed commands (see +.Sx Aliases +above). Enabled by default for non-interactive shells. +.It Fl i Ic interactive +Enable interactive mode. This can only be set/unset when the shell is invoked. +.It Fl k Ic keyword Parameter assignments are recognized anywhere in a command. -T} -\-l login T{ -The shell is a login shell \- this can only be set/unset when the shell is -invoked (see Shell Startup above). -T} -\-m monitor T{ +.It Fl l Ic login +The shell is a login shell. This can only be set/unset when the shell is +invoked (see +.Sx Shell startup +above). +.It Fl m Ic monitor Enable job control (default for interactive shells). -T} -\-n noexec T{ -Do not execute any commands \- useful for checking the syntax of scripts +.It Fl n lc noexec +Do not execute any commands. Useful for checking the syntax of scripts (ignored if interactive). -T} -\-p privileged T{ -Set automatically if, when the shell starts, the read uid or gid does not -match the effective uid or gid, respectively. -See Shell Startup above for a description of what this -means. -T} --r restricted T{ -Enable restricted mode \(em this option can only be used when the shell is -invoked. See Shell Startup above for a description of what this -means. -T} -\-s stdin T{ -If used when the shell is invoked, commands are read from standard input. -Set automatically if the shell is invoked with no arguments. -.sp -When \fB\-s\fP is used in the \fBset\fP command, it causes the specified -arguments to be sorted before assigning them to the positional parameters -(or to array \fIname\fP, if \fB\-A\fP is used). -T} -\-u nounset T{ -Referencing of an unset parameter is treated as an error, unless -one of the \fB\-\fP, \fB+\fP or \fB=\fP modifiers is used. -T} -\-v verbose T{ +.It Fl p Ic privileged +Set automatically if, when the shell starts, the read UID or GID does not match +the effective UID (EUID) or GID (EGID), respectively. See +.Sx Shell startup +above for a description of what this means. +.It Fl r Ic restricted +Enable restricted mode. This option can only be used when the shell is invoked. +See +.Sx Shell startup +above for a description of what this means. +.It Fl s Ic stdin +If used where the shell is invoked, commands are read from standard input. Set +automatically if the shell is invoked with no arguments. +.Pp +When +.Fl s +is used with the +.Ic set +command it causes the specified arguments to be sorted before assigning them to +the positional parameters (or to array +.Ar name , +if +.Fl A +is used). +.It Fl u Ic nounset +Referencing of an unset parameter is treated as an error, unless one of the +.Dq \&- , +.Dq \&+ +or +.Dq = +modifiers is used. +.It Fl v Ic verbose Write shell input to standard error as it is read. -T} -\-x xtrace T{ -Print commands and parameter assignments when they are executed, -preceded by the value of \fBPS4\fP. -T} -\-X markdirs T{ -Mark directories with a trailing \fB/\fP during file name generation. -T} - bgnice T{ +.It Fl x Ic xtrace +Print commands and parameter assignments when they are executed, preceded by +the value of +.Ev PS4 . +.It Fl X Ic markdirs +Mark directories with a trailing +.Dq / +during file name generation. +.It Ic bgnice Background jobs are run with lower priority. -T} - braceexpand T{ -Enable brace expansion (aka, alternation). -T} - emacs T{ -Enable BRL emacs-like command line editing (interactive shells only); -see Emacs Interactive Input Line Editing. -T} - gmacs T{ -Enable gmacs-like (Gosling emacs) command line editing (interactive shells -only); -currently identical to emacs editing except that transpose (^T) acts -slightly differently. -T} - ignoreeof T{ -The shell will not exit on when end-of-file is read, \fBexit\fP must be used. -T} - nohup T{ -Do not kill running jobs with a \fBHUP\fP signal when a login shell exists. -Currently set by default, but this will change in the future to be compatible -with the original Korn shell (which doesn't have this option, but does -send the \fBHUP\fP signal). -T} - nolog T{ -No effect \- in the original Korn shell, this prevents function definitions -from being stored in the history file. -T} - physical T{ -Causes the \fBcd\fP and \fBpwd\fP commands to use `physical' -(\fIi.e.\fP, the filesystem's) \fB..\fP directories instead of `logical' -directories (\fIi.e.\fP, the shell handles \fB..\fP, which allows the user -to be oblivious of symlink links to directories). -Clear by default. Note that setting -this option does not effect the current value of the \fBPWD\fP parameter; -only the \fBcd\fP command changes \fBPWD\fP. -See the \fBcd\fP and \fBpwd\fP commands above for more details. -T} - posix T{ -Enable posix mode. See POSIX Mode above. -T} - vi T{ +.It Ic braceexapnd +Enable brace expansion (a.k.a., alternation). +.It Ic emacs +Enable BRL emacs-like command line editing (interactive shells only); see +.Sx Emacs interactive input line editing +below. +.It Ic gmacs +Enable gmacs-like command line editing (interactive shells only). Currently +identical to emacs editing except that transpose (^T) acts slightly +differently. +.It Ic ignoreeof +The shell will not exit when end-of-file is read; +.Ic exit +must be used. +.It Ic nohup +Do not kill running jobs with a +.Dv HUP +signal when a login shell exists. Currently set by default, but this will +change in the future to be compatible with the original Korn shell (which +doesn't have this option, but does send the +.Dv HUP +signal). +.It Ic nolog +No effect. In the original Korn shell, this prevents function definitions from +being stored in the history file. +.It Ic physical +Causes the +.Ic cd +and +.Ic pwd +commands to use +.Dq physical +(i.e., the filesystem's) +.Dq \&.\&. +directories instead of +.Dq logical +directories (i.e., the shell handles +.Dq \&.\&. , +which allows the user to be oblivious of symbolic links to directories). Clear +by default. Note that setting this option does not affect the current value of +the +.Ev PWD +parameter; only the +.Ic cd +command changes +.Ev PWD . +See the +.Ic cd +and +.Ic pwd +commands above for more details. +.It Ic posix +Enable POSIX mode. See +.Sx POSIX mode +above. +.It Ic vi Enable vi-like command line editing (interactive shells only). -T} - viraw T{ -No effect \- in the original Korn shell, unless viraw was set, the vi command -line mode would let the tty driver do the work until ESC (^[) was entered. -pdksh is always in viraw mode. -T} - vi-esccomplete T{ -In vi command line editing, do command / file name completion when -escape (^[) is entered in command mode. -T} - vi-show8 T{ -Prefix characters with the eighth bit set with `M-'. -If this option is not set, characters in the range -128-160 are printed as is, which may cause problems. -T} - vi-tabcomplete T{ -In vi command line editing, do command / file name completion when -tab (^I) is entered in insert mode. -T} -.TE -.sp -These options can also be used upon invocation of the shell. The current -set of options (with single letter names) can be found in the -parameter \fB\-\fP. -\fBset -o\fP with no option name will list all the options and whether each -is on or off; \fBset +o\fP will print the long names of all options that -are currently on. -.sp -Remaining arguments, if any, are positional parameters and are assigned, -in order, to the -positional parameters (\fIi.e.\fP, \fB1\fP, \fB2\fP, \fIetc.\fP). -If options are ended with \fB\-\-\fP and there are no remaining arguments, -all positional parameters are cleared. -If no options or arguments are given, then the values of all names are printed. -For unknown historical reasons, a lone \fB\-\fP option is treated specially: -it clears both the \fB\-x\fP and \fB\-v\fP options. -.\"}}} -.\"{{{ shift [number] -.IP "\fBshift\fP [\fInumber\fP]" -The positional parameters \fInumber\fP+1, \fInumber\fP+2 \fIetc.\fP\& are -renamed to \fB1\fP, \fB2\fP, \fIetc.\fP -\fInumber\fP defaults to 1. -.\"}}} -.\"{{{ test expression, [ expression ] -.IP "\fBtest\fP \fIexpression\fP" -.IP "\fB[\fP \fIexpression\fP \fB]\fP" -\fBtest\fP evaluates the \fIexpression\fP and returns zero status if -true, and 1 status if false and greater than 1 if there was an error. -It is normally used as the -condition command of \fBif\fP and \fBwhile\fP statements. -The following basic expressions are available: -.sp -.TS -afB ltw(2.8i). -\fIstr\fP T{ -\fIstr\fP has non-zero length. Note that there is the potential -for problems if \fIstr\fP turns out to be an operator (\fIe.g.\fP, \fB-r\fP) -- it is generally better to use a test like -\fB[ X"\fP\fIstr\fP\fB" != X ]\fP -instead (double quotes are used in case \fIstr\fP contains spaces or file -globing characters). -T} -\-r \fIfile\fP T{ -\fIfile\fP exists and is readable -T} -\-w \fIfile\fP T{ -\fIfile\fP exists and is writable -T} -\-x \fIfile\fP T{ -\fIfile\fP exists and is executable -T} -\-a \fIfile\fP T{ -\fIfile\fP exists -T} -\-e \fIfile\fP T{ -\fIfile\fP exists -T} -\-f \fIfile\fP T{ -\fIfile\fP is a regular file -T} -\-d \fIfile\fP T{ -\fIfile\fP is a directory -T} -\-c \fIfile\fP T{ -\fIfile\fP is a character special device -T} -\-b \fIfile\fP T{ -\fIfile\fP is a block special device -T} -\-p \fIfile\fP T{ -\fIfile\fP is a named pipe -T} -\-u \fIfile\fP T{ -\fIfile\fP's mode has setuid bit set -T} -\-g \fIfile\fP T{ -\fIfile\fP's mode has setgid bit set -T} -\-k \fIfile\fP T{ -\fIfile\fP's mode has sticky bit set -T} -\-s \fIfile\fP T{ -\fIfile\fP is not empty -T} -\-O \fIfile\fP T{ -\fIfile\fP's owner is the shell's effective user-ID -T} -\-G \fIfile\fP T{ -\fIfile\fP's group is the shell's effective group-ID -T} -\-h \fIfile\fP T{ -\fIfile\fP is a symbolic link -T} -\-H \fIfile\fP T{ -\fIfile\fP is a context dependent directory (only useful on HP-UX) -T} -\-L \fIfile\fP T{ -\fIfile\fP is a symbolic link -T} -\-S \fIfile\fP T{ -\fIfile\fP is a socket -T} -\-o \fIoption\fP T{ -shell \fIoption\fP is set (see \fBset\fP command above for list of options). -As a non-standard extension, if the option starts with a \fB!\fP, the test -is negated; the test always fails if option doesn't exist (thus -.RS -\fB[ -o \fP\fIfoo\fP \fB-o -o !\fP\fIfoo\fP \fB]\fP -.RE -returns true if and only if option \fIfoo\fP exists). -T} -\fIfile\fP \-nt \fIfile\fP T{ -first \fIfile\fP is newer than second \fIfile\fP -T} -\fIfile\fP \-ot \fIfile\fP T{ -first \fIfile\fP is older than second \fIfile\fP -T} -\fIfile\fP \-ef \fIfile\fP T{ -first \fIfile\fP is the same file as second \fIfile\fP -T} -\-t\ [\fIfd\fP] T{ -file descriptor is a tty device. -If the posix option (\fBset \-o posix\fP, see POSIX Mode above) is not -set, \fIfd\fP may be left out, in which case it is taken to be 1 -(the behaviour differs due to the special POSIX rules described below). -T} -\fIstring\fP T{ -\fIstring\fP is not empty -T} -\-z\ \fIstring\fP T{ -\fIstring\fP is empty -T} -\-n\ \fIstring\fP T{ -\fIstring\fP is not empty -T} -\fIstring\fP\ =\ \fIstring\fP T{ -strings are equal -T} -\fIstring\fP\ ==\ \fIstring\fP T{ -strings are equal -T} -\fIstring\fP\ !=\ \fIstring\fP T{ -strings are not equal -T} -\fInumber\fP\ \-eq\ \fInumber\fP T{ -numbers compare equal -T} -\fInumber\fP\ \-ne\ \fInumber\fP T{ -numbers compare not equal -T} -\fInumber\fP\ \-ge\ \fInumber\fP T{ -numbers compare greater than or equal -T} -\fInumber\fP\ \-gt\ \fInumber\fP T{ -numbers compare greater than -T} -\fInumber\fP\ \-le\ \fInumber\fP T{ -numbers compare less than or equal -T} -\fInumber\fP\ \-lt\ \fInumber\fP T{ -numbers compare less than -T} -.TE -.sp +.It Ic viraw +No effect. In the original Korn shell, unless +.Ic viraw +was set, the vi command line mode would let the tty driver do the work until +ESC (^[) was entered. +.Nm pdksh +is always in viraw mode. +.It Ic vi-esccomplete +In vi command line editing, do command and file name completion when escape +(^[) is entered in command mode. +.It Ic vi-show8 +Prefix characters with the eighth bit set with +.Dq M\&- . +If this option is not set, characters in the range 128-160 are printed as is, +which may cause problems. +.It Ic vi-tabcomplete +In vi command line editing, do command and file name completion when tab (^I) +is entered in insert mode. +.El +.Pp +These options can also be used upon invocation of the shell. The current set of +options (with single letter names) can be found in the parameter +.Dv \&- . +.Ic set Fl o +with no option name will list all the options and whether each is on or off; +.Ic set +o +will print the long names of all options that are currently on. +.Pp +Remaining arguments, if any, are positional parameters and are assigned, in +order, to the positional parameters (i.e., $1, $2, etc.). If options end with +.Dq \&-\&- +and there are no remaining arguments, all positional parameters are cleared. If +no options or arguments are given, the values of all names are printed. For +unknown historical reasons, a lone +.Dq \&- +option is treated specially -- it clears both the +.Fl x +and +.Fl v +options. +.It Ic shift Op Ar number +The positional parameters +.Ar number Ns +1 , +.Ar number Ns +2 , +etc. are renamed to +.Dq 1 , +.Dq 2 , +etc. +.Ar number +defaults to 1. +.It Ic test Ar expression +.It Ic \&[ Ar expression Ic \&] +.Ic test +evaluates the +.Ar expression +and returns zero status if true, 1 status if fase, and greater than 1 if there +was an error. It is normally used as the condition command of +.Ic if +and +.Ic while +statements. The following basic expressions are available: +.Bl -tag -width 17n +.It Ar str +.Ar str +has non-zero length. Note that there is the potential for problems if +.Ar str +turns out to be an operator (e.g., +.Fl r ) . +It is generally better to use a test like +.Sm off +.Ic \&[\ X\&" Ar str Ic \&" Ic \ \&] +.Sm on +instead (double quotes are used in case +.Ar str +contains spaces or file globbing characters). +.It Fl r Ar file +.Ar file +exists and is readable. +.It Fl w Ar file +.Ar file +exists and is writable. +.It Fl x Ar file +.Ar file +exists and is executable. +.It Fl a Ar file +.Ar file +exists. +.It Fl e Ar file +.Ar file +exists. +.It Fl f Ar file +.Ar file +is a regular file. +.It Fl d Ar file +.Ar file +is a directory. +.It Fl c Ar file +.Ar file +is a character special device. +.It Fl b Ar file +.Ar file +is a block special device. +.It Fl p Ar file +.Ar file +is a named pipe. +.It Fl u Ar file +.Ar file Ns 's +mode has setuid bit set. +.It Fl g Ar file +.Ar file Ns 's +mode has setgid bit set. +.It Fl k Ar file +.Ar file Ns 's +mode has sticky bit set. +.It Fl s Ar file +.Ar file +is not empty. +.It Fl O Ar file +.Ar file Ns 's +owned is the shell's effective user ID. +.It Fl G Ar file +.Ar file Ns 's +group is the shell's effective group ID. +.It Fl h Ar file +.Ar file +is a symbolic link. +.It Fl H Ar file +.Ar file +is a context dependent directory (only useful on HP-UX). +.It Fl L Ar file +.Ar file +is a symbolic link. +.It Fl S Ar file +.Ar file +is a socket. +.It Fl o Ar option +Shell +.Ar option +is set (see +.Ic set +command above for a list of options). As a non-standard extension, if the +option starts with a +.Dq \&! , +the test is negated; the test always fails if +.Ar option +doesn't exist (thus +.Ic \&[ -o Ar foo +.Ic -o -o \&! Ns Ar foo Ic \&] +returns true if and only if option +.Ar foo +exists). +.It Ar file Fl nt Ar file +first +.Ar file +is newer than second +.Ar file . +.It Ar file Fl ot Ar file +first +.Ar file +is older than second +.Ar file . +.It Ar file Fl ef Ar file +first +.Ar file +is the same file as second +.Ar file . +.It Fl t Op Ar fd +File descriptor +.Ar fd +is a tty device. If the +.Ic posix +option is not set, +.Ar fd +may be left out, in which case it is taken to be 1 (the behaviour differs due +to the special POSIX rules described below). +.It Ar string +.Ar string +is not empty. +.It Fl z Ar string +.Ar string +is empty. +.It Fl n Ar string +.Ar string +is not empty. +.It Ar string No = Ar string +Strings are equal. +.It Ar string No == Ar string +Strings are equal. +.It Ar string No \&!= Ar string +Strings are not equal. +.It Ar number Fl eq Ar number +Numbers compare equal. +.It Ar number Fl ne Ar number +Numbers compare not equal. +.It Ar number Fl ge Ar number +Numbers compare greater than or equal. +.It Ar number Fl gt Ar number +Numbers compare greater than. +.It Ar number Fl le Ar number +Numbers compare less than or equal. +.It Ar number Fl \< Ar number +Numbers compare less than. +.El +.Pp The above basic expressions, in which unary operators have precedence over -binary operators, may be combined with the following operators -(listed in increasing order of precedence): -.sp -.TS -afB l. -\fIexpr\fP \-o \fIexpr\fP logical or -\fIexpr\fP \-a \fIexpr\fP logical and -! \fIexpr\fP logical not -( \fIexpr\fP ) grouping -.TE -.sp -On operating systems not supporting \fB/dev/fd/\fP\fIn\fP devices -(where \fIn\fP is a file descriptor number), -the \fBtest\fP command will attempt to fake it for all tests that -operate on files (except the \fB-e\fP test). -I.e., \fB[ -w /dev/fd/2 ]\fP tests if file descriptor 2 is writable. -.sp -Note that some special rules are applied (courtesy of POSIX) if the -number of arguments to \fBtest\fP or \fB[\fP \&... \fB]\fP is less than -five: if leading \fB!\fP arguments can be stripped such that only one -argument remains then a string length test is performed (again, even if -the argument is a unary operator); -if leading \fB!\fP arguments can be stripped such that three -arguments remain and the second argument is a binary operator, then the -binary operation is performed (even if first argument is a unary -operator, including an unstripped \fB!\fP). -.sp -\fBNote:\fP A common mistake is to use \fBif [ $foo = bar ]\fP which -fails if parameter \fBfoo\fP is null or unset, if it has embedded spaces -(\fIi.e.\fP, \fBIFS\fP characters), or if it is a unary operator like \fB!\fP or -\fB\-n\fP. Use tests like \fBif [ "X$foo" = Xbar ]\fP instead. -.\"}}} -.\"{{{ times -.IP \fBtimes\fP -Print the accumulated user and system times used by the shell and by -processes which have exited that the shell started. -.\"}}} -.\"{{{ trap [handler signal ...] -.IP "\fBtrap\fP [\fIhandler\fP \fIsignal ...\fP]" -Sets trap handler that is to be executed when any of the specified signals -are received. -\fBHandler\fP is either a null string, indicating the signals are to -be ignored, a minus (\fB\-\fP), indicating that the default action is to -be taken for the signals (see signal(2 or 3)), or a string containing shell -commands to be evaluated and executed at the first opportunity (\fIi.e.\fP, -when the current command completes, or before printing the next \fBPS1\fP +binary operators, may be combined with the following operators (listed in +increasing order of precedence): +.Pp +.Bl -tag -width "expr -o expr" -compact +.It Ar expr Fl o Ar expr +Logical OR. +.It Ar expr Fl a Ar expr +Logical AND. +.It Ic \&! Ar expr +Logical NOT. +.It Ic \&( Ar expr Ic \&) +Grouping. +.El +.Pp +On operating systems not supporting +.Pa /dev/fd/ Ns Ar n +devices (where +.Ar n +is a file descriptor number), the +.Ic test +command will attempt to fake it for all tests that operate on files (except the +.Fl e +test). For example, +.Ic \&[ -w /dev/fd/2 \&] +tests if file descriptor 2 is writable. +.Pp +Note that some special rules are applied (courtesy of POSIX) if the number of +arguments to +.Ic test +or +.Ic \&[ ... \&] +is less than five; if leading +.Dq \&! +arguments can be stripped such that only one argument remains then a string +length test is performed (again, even if the argument is a unary operator); if +leading +.Dq \&! +arguments can be stripped such that three arguments remain and the second +argument is a binary operator, then the binary operation is performed (even +if the first argument is a unary operator, including an unstripped +.Dq \&! ) . +.Pp +NOTE: A common mistake is to use +.Ic if \&[ $foo = bar \&] +which fails if parameter +.Ic foo +is +.Dv NULL +or unset, if it has embedded spaces (i.e., +.Ev IFS +characters), or if it is a unary operator like +.Dq Ic \&! +or +.Dq Fl n . +Use tests like +.Ic if \&[ \&"X$foo\&" = Xbar \&] +instead. +.It Ic times +Print the accumulated user and system times used by the shell and by processes +which have exited that the shell started. +.It Ic trap Op Ar handler signal ... +Sets trap handler that is to be executed when any of the specified signals are +received. +.Ar handler +is either a +.Dv NULL +string, indicating the signals are to be ignored, a minus sign +.Pq Sq \&- , +indicating that the default action is to be taken for the signals (see +.Xr signal 3 ) , +or a string containing shell commands to be evaluated and executed at the first +opportunity (i.e., when the current command completes, or before printing the +next +.Ev PS1 prompt) after receipt of one of the signals. -\fBSignal\fP is the name of a signal (\fIe.g.\fP, PIPE or ALRM) or the number -of the signal (see \fBkill \-l\fP command above). -There are two special signals: \fBEXIT\fP (also known as \fB0\fP), which -is executed when the shell is about to exit, and \fBERR\fP which is -executed after an error occurs (an error is something that would cause -the shell to exit if the \fB\-e\fP or \fBerrexit\fP option were set \(em -see \fBset\fP command above). -\fBEXIT\fP handlers are executed in the environment of the last executed -command. -Note that for non-interactive shells, the trap handler cannot be changed for -signals that were ignored when the shell started. -.sp -With no arguments, \fBtrap\fP lists, as a series of \fBtrap\fP commands, -the current state of the traps that have been set since the shell started. -.sp -.\" todo: add these features (trap DEBUG, trap ERR/EXIT in function) -The original Korn shell's \fBDEBUG\fP trap and the handling of \fBERR\fP and -\fBEXIT\fP traps in functions are not yet implemented. -.\"}}} -.\"{{{ true -.IP \fBtrue\fP +.Ar signal +is the name of a signal (e.g., +.Dv PIPE +or +.Dv ALRM ) +or the number of the signal (see +.Ic kill -l +command above). There are two special signals: +.Dv EXIT +(also known as 0), which is executed when the shell is about to exit, and +.Dv ERR , +which is executed after an error occurs (an error is something that would cause +the shell to exit if the +.Fl e +or +.Ic errexit +option were see -- see +.Ic set +command above). +.Dv EXIT +handlers are executed in the environment of the last executed command. Note +that for non-interactive shells, the trap handler cannot be changed for signals +that were ignored when the shell started. +.Pp +With no arguments, +.Ic trap +lists, as a series of +.Ic trap +commands, the current start of the traps that have been set since the shell +started. +.Pp +The original Korn shell's +.Dv DEBUG +trap and the handling of +.Dv ERR +and +.Dv EXIT +traps in functions are not yet implemented. +.It Ic true A command that exits with a zero value. -.\"}}} -.\"{{{ typeset [[+-Ulprtux] [-L[n]] [-R[n]] [-Z[n]] [-i[n]] | -f [-tux]] [name[=value] ...] -.IP "\fBtypeset\fP [[\(+-Ulprtux] [\fB\-L\fP[\fIn\fP]] [\fB\-R\fP[\fIn\fP]] [\fB\-Z\fP[\fIn\fP]] [\fB\-i\fP[\fIn\fP]] | \fB\-f\fP [\fB\-tux\fP]] [\fIname\fP[\fB=\fP\fIvalue\fP] ...]" -Display or set parameter attributes. -With no \fIname\fP arguments, parameter attributes are displayed: if no options -arg used, the current attributes of all parameters are printed as typeset -commands; if an option is given (or \fB\-\fP with no option letter) -all parameters and their values with the specified attributes are printed; -if options are introduced with \fB+\fP, parameter values are not printed. -.sp -If \fIname\fP arguments are given, the attributes of the named parameters -are set (\fB\-\fP) or cleared (\fB+\fP). -Values for parameters may optionally be specified. -If typeset is used inside a function, any newly created parameters are local -to the function. -.sp -When \fB\-f\fP is used, typeset operates on the attributes of functions. -As with parameters, if no \fIname\fPs are given, functions are listed -with their values (\fIi.e.\fP, definitions) unless options are introduced with -\fB+\fP, in which case only the function names are reported. -.sp -.TS -expand; -afB lw(4.5i). -\-L\fIn\fP T{ -Left justify attribute: \fIn\fP specifies the field width. -If \fIn\fP is not specified, the current width of a parameter (or the -width of its first assigned value) is used. -Leading white space (and zeros, if used with the \fB\-Z\fP option) is stripped. -If necessary, values are either truncated or space padded to fit the +.It Xo Ic typeset No [[+-Ulprtux]\ [-L[n]]\ [-R[n]]\ [-Z[n]]\ [-i[n]]\ |\ -f\& +.Li [-tux]]\ [name[=value]\ ...] +.Xc +Display or set parameter attributes. With no +.Ar name +arguments, parameter attributes are displayed; if no options are used, the +current attributes of all parameters are printed as +.Ic typeset +commands; if an option is given (or +.Dq \&- +with no option letter), all parameters and their values with the specified +attributes are printed; if options are introduced with +.Dq \&+ , +parameter values are not printed. +.Pp +If +.Ar name +arguments are given, the attributes of the named parameters are set +.Pq Ic \&- +or cleared +.Pq Ic \&+ . +Values for parameters may optionally be specified. If +.Ic typeset +is used inside a function, any newly created parameters are local to the +function. +.Pp +When +.Fl f +is used, +.Ic typeset +operates on the attributes of functions. As with parameters, if no +.Ar name Ns s +are given, functions are listed with their values (i.e., definitions) unless +options are introduced with +.Dq \&+ , +in which case only the function names are reported. +.Bl -tag -width 3n +.It Fl L Ns Ar n +Left justify attribute. +.Ar n +specifies the field width. If +.Ar n +is not specified, the current width of a parameter (or the width of its first +assigned value) is used. Leading whitespace (and zeros, if used with the +.Fl Z +option) is stripped. If necessary, values are either truncated or space padded +to fit the field width. +.It Fl R Ns Ar n +Right justify attribute. +.Ar n +specifies the field width. If +.Ar n +is not specified, the current width of a parameter (or the width of its first +assigned value) is used. Trailing whitespace is stripped. If necessary, values +are either stripped of leading characters or space padded to make them fit the field width. -T} -\-R\fIn\fP T{ -Right justify attribute: \fIn\fP specifies the field width. -If \fIn\fP is not specified, the current width of a parameter (or the -width of its first assigned value) is used. -Trailing white space are stripped. -If necessary, values are either stripped of leading characters -or space padded to make them fit the field width. -T} -\-Z\fIn\fP T{ -Zero fill attribute: if not combined with \fB\-L\fP, this is the -same as \fB\-R\fP, except zero padding is used instead of space padding. -T} -\-i\fIn\fP T{ -integer attribute: -\fIn\fP specifies the base to use when displaying the integer -(if not specified, the base given in the first assignment is used). -Parameters with this attribute may be assigned values containing -arithmetic expressions. -T} -\-U T{ -unsigned integer attribute: integers are printed as unsigned values -(only useful when combined with the \fB\-i\fP option). -This option is not in the original Korn shell. -T} -\-f T{ -Function mode: display or set functions and their attributes, instead of +.It Fl Z Ns Ar n +Zero fill attribute. If not combined with +.Fl L , +this is the same as +.Fl R , +except zero padding is used instead of space padding. +.It Fl i Ns Ar n +Integer attribute. +.Ar n +specifies the base to use when displaying the integer (if not specified, the +base given in the first assignment is used). Parameters with this attribute may +be assigned values containing arithmetic expressions. +.It Fl U +Unsigned integer attribute. Integers are printed as unsigned values (only +useful when combined with the +.Fl i +option). This option is not in the original Korn shell. +.It Fl f +Function mode. Display or set functions and their attributes, instead of parameters. -T} -\-l T{ -Lower case attribute: all upper case characters in values are converted to -lower case. -(In the original Korn shell, this parameter meant `long integer' when used -with the \fB\-i\fP option). -T} -\-p T{ -Print complete typeset commands that can be used to re-create the -attributes (but not the values) of parameters. -This is the default action (option exists for ksh93 compatability). -T} -\-r T{ -Readonly attribute: parameters with the this attribute may not be assigned to -or unset. -Once this attribute is set, it can not be turned off. -T} -\-t T{ -Tag attribute: has no meaning to the shell; provided for application use. -.sp -For functions, \fB\-t\fP is the trace attribute. -When functions with the trace attribute are executed, the \fBxtrace\fP (\fB\-x\fP) shell option is temporarily turned on. -T} -\-u T{ -Upper case attribute: all lower case characters in values are converted to -upper case. -(In the original Korn shell, this parameter meant `unsigned integer' when used -with the \fB\-i\fP option, which meant upper case letters would never be used -for bases greater than 10. See the \fB\-U\fP option). -.sp -For functions, \fB\-u\fP is the undefined attribute. See Functions above -for the implications of this. -T} -\-x T{ -Export attribute: parameters (or functions) are placed in the environment of -any executed commands. Exported functions are not implemented yet. -T} -.TE -.\"}}} -.\"{{{ ulimit [-acdfHlmnpsSt] [value] -.IP "\fBulimit\fP [\fB\-acdfHlmnpsStvw\fP] [\fIvalue\fP]" -Display or set process limits. -If no options are used, the file size limit (\fB\-f\fP) is assumed. -\fBvalue\fP, if specified, may be either be an arithmetic expression or the -word \fBunlimited\fP. -The limits affect the shell and any processes created by the shell after -a limit is imposed. -Note that some systems may not allow limits to be increased once they -are set. -Also note that the types of limits available are system dependent \- some -systems have only the \fB\-f\fP limit. -.RS -.IP \fB\-a\fP -Displays all limits; unless \fB\-H\fP is used, soft limits are displayed. -.IP \fB\-H\fP +.It Fl l +Lower case attribute. All upper case characters in values are converted to +lower case. (In the original Korn shell, this parameter meant +.Dq long integer +when used with the +.Fl i +option.) +.It Fl p +Print complete +.Ic typeset +commands that can be used to re-create the attributes (but not the values) or +parameters. This is the default action (option exists for ksh93 compatibility). +.It Fl r +Read-only attribute. Parameters with this attribute may not be assigned to or +unset. Once this attribute is set, it can not be turned off. +.It Fl t +Tag attribute. Has no meaning to the shell; provided for application use. +.Pp +For functions, +.Fl t +is the trace attribute. When functions with the trace attribute are executed, +the +.Ic xtrace +.Pq Fl x +shell option is temporarily turned on. +.It Fl u +Upper case attribute. All lower case characters in values are converted to +upper case. (In the original Korn shell, this parameter meant +.Dq unsigned integer +when used with the +.Fl i +option, which meant upper case letters would never be used for bases greater +than 10. See the +.Fl U +option.) +.Pp +For functions, +.Fl u +is the undefined attribute. See +.Sx Functions +above for the implications of this. +.It Fl x +Export attribute. Parameters (or functions) are placed in the environment of +any executed commands. Exported functions are not yet implemented. +.El +.It Xo Ic ulimit Op Fl acdfHlmnpsStvw +.Op Ar value +.Xc +Display or set process limits. If no options are used, the file size limit +.Pq Fl f +is assumed. +.Ar value , +if specified, may be either an arithmetic expression or the word +.Dq unlimited . +The limits affect the shell and any processes created by the shell after a +limit is imposed. Note that some systems may not allow limits to be increased +once they are set. Also note that the types of limits available are system +dependent -- some systems have only the +.Fl f +limit. +.Bl -tag -width 5n +.It Fl a +Displays all limits; unless +.Fl H +is used, soft limits are displayed. +.It Fl H Set the hard limit only (default is to set both hard and soft limits). -.IP \fB\-S\fP +.It Fl S Set the soft limit only (default is to set both hard and soft limits). -.IP \fB\-c\fP -Impose a size limit of \fIn\fP blocks on the size of core dumps. -.IP \fB\-d\fP -Impose a size limit of \fIn\fP kbytes on the size of the data area. -.IP \fB\-f\fP -Impose a size limit of \fIn\fP blocks on files written by the shell and -its child processes (files of any size may be read). -.IP \fB\-l\fP -Impose a limit of \fIn\fP kbytes on the amount of locked (wired) physical -memory. -.IP \fB\-m\fP -Impose a limit of \fIn\fP kbytes on the amount of physical memory used. -.IP \fB\-n\fP -Impose a limit of \fIn\fP file descriptors that can be open at once. -.IP \fB\-p\fP -Impose a limit of \fIn\fP processes that can be run by the user at any one -time. -.IP \fB\-s\fP -Impose a size limit of \fIn\fP kbytes on the size of the stack area. -.IP \fB\-t\fP -Impose a time limit of \fIn\fP cpu seconds to be used by each process. -.PP -As far as \fBulimit\fP is concerned, a block is 512 bytes. -.RE -.\"}}} -.\"{{{ umask [-S] [mask] -.IP "\fBumask\fP [\fB\-S\fP] [\fImask\fP]" -.RS -Display or set the file permission creation mask, or umask (see \fIumask\fP(2)). -If the \fB\-S\fP option is used, the mask displayed or set is symbolic, -otherwise it is an octal number. -.sp -Symbolic masks are like those used by \fIchmod\fP(1): -.RS -[\fBugoa\fP]{{\fB=+-\fP}{\fBrwx\fP}*}+[\fB,\fP...] -.RE -in which the first group of characters is the \fIwho\fP part, the second -group is the \fIop\fP part, and the last group is the \fIperm\fP part. -The \fIwho\fP part specifies which part of the umask is to be modified. -The letters mean: -.RS -.IP \fBu\fP -the user permissions -.IP \fBg\fP -the group permissions -.IP \fBo\fP -the other permissions (non-user, non-group) -.IP \fBa\fP -all permissions (user, group and other) -.RE -.sp -The \fIop\fP part indicates how the \fIwho\fP permissions are to be modified: -.RS -.IP \fB=\fP -set -.IP \fB+\fP -added to -.IP \fB\-\fP -removed from -.RE -.sp -The \fIperm\fP part specifies which permissions are to be set, added or removed: -.RS -.IP \fBr\fP -read permission -.IP \fBw\fP -write permission -.IP \fBx\fP -execute permission -.RE -.sp -When symbolic masks are used, they describe what permissions may -be made available (as opposed to octal masks in which a set bit means -the corresponding bit is to be cleared). -Example: `ug=rwx,o=' sets the mask so files will not be readable, writable -or executable by `others', and is equivalent (on most systems) to the octal -mask `07'. -.RE -.\"}}} -.\"{{{ unalias [-adt] name ... -.IP "\fBunalias\fP [\fB\-adt\fP] [\fIname1\fP ...]" -The aliases for the given names are removed. -If the \fB\-a\fP option is used, all aliases are removed. -If the \fB\-t\fP or \fB\-d\fP options are used, the indicated operations -are carried out on tracked or directory aliases, respectively. -.\"}}} -.\"{{{ unset [-fv] parameter ... -.IP "\fBunset\fP [\fB\-fv\fP] \fIparameter\fP ..." -Unset the named parameters (\fB\-v\fP, the default) or functions (\fB\-f\fP). -The exit status is non-zero if any of the parameters were already unset, -zero otherwise. -.\"}}} -.\"{{{ wait [job] -.IP "\fBwait\fP [\fIjob\fP]" -Wait for the specified job(s) to finish. -The exit status of wait is that of the last specified job: -if the last job is killed by a signal, the exit status is 128 + the -number of the signal (see \fBkill \-l\fP \fIexit-status\fP above); if the last -specified job can't be found (because it never existed, or had already -finished), the exit status of wait is 127. -See Job Control below for the format of \fIjob\fP. -\fBWait\fP will return if a signal for which a trap has been set is received, -or if a HUP, INT or QUIT signal is received. -.sp -If no jobs are specified, \fBwait\fP waits for all currently running jobs -(if any) to finish and exits with a zero status. -If job monitoring is enabled, the completion status of jobs is -printed (this is not the case when jobs are explicitly specified). -.\"}}} -.\"{{{ whence [-pv] [name ...] -.IP "\fBwhence\fP [\fB\-pv\fP] [name ...]" -For each name, the type of command is listed (reserved word, built-in, alias, -function, tracked alias or executable). -If the \fB\-p\fP option is used, a path search done even if \fIname\fP -is a reserved word, alias, \fIetc.\fP -Without the \fB\-v\fP option, \fBwhence\fP is similar to \fBcommand \-v\fP -except that \fBwhence\fP will find reserved words and won't print aliases -as alias commands; -with the \fB\-v\fP option, \fBwhence\fP is the same as \fBcommand \-V\fP. -Note that for \fBwhence\fP, the \fB\-p\fP option does not affect the search -path used, as it does for \fBcommand\fP. -If the type of one or more of the names could not be determined, the -exit status is non-zero. -.\"}}} -.\"}}} -.\"{{{ job control (and its built-in commands) -.SS "Job Control" -Job control refers to the shell's ability to monitor and control \fBjobs\fP, -which are processes or groups of processes created for commands or pipelines. -At a minimum, the shell keeps track of the status of the background -(\fIi.e.\fP, asynchronous) jobs that currently exist; this information can be -displayed using the \fBjobs\fP command. -If job control is fully enabled (using \fBset \-m\fP or -\fBset \-o monitor\fP), as it is for interactive shells, -the processes of a job are placed in their own process group, -foreground jobs can be stopped by typing the suspend character from the -terminal (normally ^Z), -jobs can be restarted in either the foreground -or background, using the \fBfg\fP and \fBbg\fP commands, respectively, -and the state of the terminal is saved or restored when a foreground +.It Fl c Ar n +Impose a size limit of +.Ar n +blocks on the size of core dumps. +.It Fl d Ar n +Impose a size limit of +.Ar n +kilobytes on the size of the data area. +.It Fl f Ar n +Impose a size limit of +.Ar n +blocks on files written by the shell and its child processes (files of any +size may be read). +.It Fl l Ar n +Impose a limit of +.Ar n +kilobytes on the amount of locked (wired) physical memory. +.It Fl m Ar n +Impose a limit of +.Ar n +kilobytes on the amount of physical memory used. +.It Fl n Ar n +Impose a limit of +.Ar n +file descriptors that can be open at once. +.It Fl p Ar n +Impose a limit of +.Ar n +processes that can be run by the user at any one time. +.It Fl s Ar n +Impose a size limit of +.Ar n +kilobytes on the size of the stack area. +.It Fl t Ar n +Impose a time limit of +.Ar n +CPU seconds to be used by each process. +.It Fl v Ar n +Impose a limit of +.Ar n +kbytes on the amount of virtual memory used; on some systems this is the +maximum allowable virtual address (in bytes, not kbytes). +.It Fl w Ar n +Impose a limit of +.Ar n +kbytes on the amount of swap space used. +.El +.Pp +As far as +.Ic ulimit +is concerned, a block is 512 bytes. +.It Xo Ic umask Op Fl S +.Op Ar mask +.Xc +Display or set the file permission creation mask, or umask (see +.Xr umask 2 ) . +If the +.Fl S +option is used, the mask displayed or set is symbolic, otherwise it is an +octal number. +.Pp +Symbolic masks are like those used by +.Xr chmod 1 . +When used, they describe what permissions may be made available (as opposed to +octal masks in which a set bit means the corresponding bit is to be cleared). +For example, +.Dq ug=rwx,o= +sets the mask so files with not be readable, writable or executable by +.Dq others , +and is equivalent (on most systems) to the octal mask +.Dq 007 . +.It Xo Ic unalias Op Fl adt +.Op Ar name1 ... +.Xc +The aliases for the given names are removed. If the +.Fl a +option is used, all aliases are removed. If the +.Fl t +or +.Fl d +options are used, the indicated operations are carried out on tracked or +directory aliases, respectively. +.It Xo Ic unset Op Fl fv +.Ar parameter ... +.Xc +Unset the named parameters +.Po +.Fl v , +the default +.Pc +or functions +.Pq Fl f . +The exit status is non-zero if any of the parameters were already unset, zero +otherwise. +.It Ic wait Op Ar job ... +Wait for the specified job(s) to finish. The exit status of +.Ic wait +is that of the last specified job; if the last job is killed by a signal, the +exit status is 128 + the number of the signal (see +.Ic kill -l Ar exit-status +above); if the last specified job can't be found (because it never existed, or +had already finished), the exit status of +.Ic wait +is 127. See +.Sx Job control +below for the format of +.Ar job . +.Ic wait +will return if a signal for which a trap has been set is received, or if a +.Dv HUP , +.Dv INT +or +.Dv QUIT +signal is received. +.Pp +If no jobs are specified, +.Ic wait +waits for all currently running jobs (if any) to finish and exits with a zero +status. If job monitoring is enabled, the completion status of jobs is printed +(this is not the case when jobs are explicitly specified). +.It Xo Ic whence Op Fl pv +.Op Ar name ... +.Xc +For each +.Ar name , +the type of command is listed (reserved word, built-in, alias, +function, tracked alias, or executable). If the +.Fl p +option is used, a path search is performed even if +.Ar name +is a reserved word, alias, etc. Without the +.Fl v +option, +.Ic whence +is similar to +.Ic command Fl v +except that +.Ic whence +will find reserved words and won't print aliases as alias commands. With the +.Fl v +option, +.Ic whence +is the same as +.Ic command Fl V . +Note that for +.Ic whence , +the +.Fl p +option does not affect the search path used, as it does for +.Ic command . +If the type of one or more of the names could not be determined, the exit +status is non-zero. +.El +.Ss Job control +Job control refers to the shell's ability to monitor and control jobs, which +are processes or groups of processes created for commands or pipelines. At a +minimum, the shell keeps track of the status of the background (i.e., +asynchronous) jobs that currently exist; this information can be displayed +using the +.Ic jobs +commands. If job control is fully enabled (using +.Ic set Fl m +or +.Ic set Fl o Ic monitor ) , +as it is for interactive shells, the processes of a job are placed in their +own process group. Foreground jobs can be stopped by typing the suspend +character from the terminal (normally ^Z), jobs can be restarted in either the +foreground or background using the +.Ic fg +and +.Ic bg +commands, and the state of the terminal is saved or restored when a foreground job is stopped or restarted, respectively. -.sp -Note that only commands that create processes (\fIe.g.\fP, -asynchronous commands, subshell commands, and non-built-in, -non-function commands) can be stopped; commands like \fBread\fP cannot be. -.sp -When a job is created, it is assigned a job-number. -For interactive shells, this number is printed inside \fB[\fP..\fB]\fP, -followed by the process-ids of the processes in the job when an asynchronous -command is run. -A job may be referred to in \fBbg\fP, \fBfg\fP, \fBjobs\fP, \fBkill\fP and -\fBwait\fP commands either by the process id of the last process in the -command pipeline (as stored in the \fB$!\fP parameter) or by prefixing the -job-number with a percent sign (\fB%\fP). +.Pp +Note that only commands that create processes (e.g., asynchronous commands, +subshell commands, and non-built-in, non-function commands) can be stopped; +commands like +.Ic read +cannot be. +.Pp +When a job is created, it is assigned a job number. For interactive shells, +this number is printed inside +.Dq \&[..\&] , +followed by the process IDs of the processes in the job when an asynchronous +command is run. A job may be referred to in +.Ic bg , +.Ic fg , +.Ic jobs , +.Ic kill , +and +.Ic wait +commands either by the process ID of the last process in the command pipeline +(as stored in the $! parameter) or by prefixing the job number with a percent +sign +.Pq Sq % . Other percent sequences can also be used to refer to jobs: -.sp -.TS -expand; -afB lw(4.5i). -%+ T{ +.Bl -tag -width 10n +.It Ic %\&+ The most recently stopped job, or, if there are no stopped jobs, the oldest running job. -T} -%%\fR, \fP% T{ -Same as \fB%+\fP. -T} -%\- T{ -The job that would be the \fB%+\fP job, if the later did not exist. -T} -%\fIn\fP T{ -The job with job-number \fIn\fP. -T} -%?\fIstring\fP T{ -The job containing the string \fIstring\fP (an error occurs if multiple jobs -are matched). -T} -%\fIstring\fP T{ -The job starting with string \fIstring\fP (an error occurs if multiple jobs -are matched). -T} -.TE -.sp -When a job changes state (\fIe.g.\fP, a background job finishes or foreground -job is stopped), the shell prints the following status information: -.RS -\fB[\fP\fInumber\fP\fB]\fP \fIflag status command\fP -.RE +.It Ic %% , % +Same as +.Ic %\&+ . +.It Ic %\&- +The job that would be the +.Ic %\&+ +job if the latter did not exist. +.It Ic % Ns Ar n +The job with job number +.Ar n . +.It Ic %\&? Ns Ar string +The job containing the string +.Ar string +(an error occurs if multiple jobs are matched). +.It Ic % Ns Ar string +The job starting with string +.Ar string +(an error occurs if multiple jobs are matched). +.El +.Pp +When a job changes state (e.g., a background job finishes or foreground job is +stopped), the shell prints the following status information: +.Pp +.Ic \&[ Ar number Ic \&] Ar flag status command +.Pp where -.IP "\ \fInumber\fP" -is the job-number of the job. -.IP "\ \fIflag\fP" -is \fB+\fP or \fB-\fP if the job is the \fB%+\fP or \fB%-\fP job, -respectively, or space if it is neither. -.IP "\ \fIstatus\fP" -indicates the current state of the job and can be -.RS -.IP "\fBRunning\fP" -the job has neither stopped or exited (note that running does not -necessarily mean consuming CPU time \(em the process could be blocked waiting -for some event). -.IP "\fBDone\fP [\fB(\fP\fInumber\fP\fB)\fP]" -the job exited. \fInumber\fP is the exit status of the job, which is -omitted if the status is zero. -.IP "\fBStopped\fP [\fB(\fP\fIsignal\fP\fB)\fP]" -the job was stopped by the indicated \fIsignal\fP (if no signal is given, -the job was stopped by SIGTSTP). -.IP "\fIsignal-description\fP [\fB(core dumped)\fP]" -the job was killed by a signal (\fIe.g.\fP, Memory\ fault, -Hangup, \fIetc.\fP \(em use -\fBkill \-l\fP for a list of signal descriptions). -The \fB(core\ dumped)\fP message indicates the process created a core file. -.RE -.IP "\ \fIcommand\fP" -is the command that created the process. -If there are multiple processes in the job, then each process will -have a line showing its \fIcommand\fP and possibly its \fIstatus\fP, +.Bl -tag -width "status" +.It Ar number +is the job number of the job. +.It Ar flag +is the +.Dq \&+ +or +.Dq \&- +character if the job is the +.Ic %\&+ or +.Ic %\&- +job, respectively, or space if it is neither. +.It Ar status +indicates the current state of the job and can be: +.Bl -tag -width "Running" +.It Cm Running +The job has neither stopped nor exited (note that running does not necessarily +mean consuming CPU time -- the process could be blocked waiting for some +event). +.It Cm Done Op Ar number +The job exited. +.Ar number +is the exit status of the job, which is omitted if the status is zero. +.It Cm Stopped Op Ar signal +The job was stopped by the indicated +.Ar signal +(if no signal is given, the job was stopped by +.Dv SIGTSTP ) . +.It Ar signal-description Op Dq core dumped +The job was killed by a signal (e.g., memory fault, hangup, etc.; use +.Ic kill -l +for a list of signal descriptions). The +.Dq core dumped +message indicates the process created a core file. +.El +.It Ar command +is the command that created the process. If there are multiple processes in +the job, each process will have a line showing its +.Ar command +and possibly its +.Ar status , if it is different from the status of the previous process. -.PP -When an attempt is made to exit the shell while there are jobs in -the stopped state, the shell warns the user that there are stopped jobs -and does not exit. -If another attempt is immediately made to exit the shell, the stopped -jobs are sent a \fBHUP\fP signal and the shell exits. -Similarly, if the \fBnohup\fP option is not set and there are running -jobs when an attempt is made to exit a login shell, the shell warns the -user and does not exit. -If another attempt is immediately made to exit the shell, the running -jobs are sent a \fBHUP\fP signal and the shell exits. -.\"}}} -.\"{{{ Emacs Interactive Input Line Editing -.SS "Emacs Interactive Input Line Editing" -When the \fBemacs\fP option is set, interactive input line editing is -enabled. \fBWarning\fP: This mode is slightly different from the emacs -mode in the original Korn shell and the 8th bit is stripped in emacs mode. -In this mode various editing commands (typically bound to one or more -control characters) cause immediate actions without waiting for a -new-line. Several editing commands are bound to particular control -characters when the shell is invoked; these bindings can be changed +.El +.Pp +When an attempt is made to exit the shell while there are jobs in the stopped +state, the shell warns the user that there are stopped jobs and does not exit. +If another attempt is immediately made to exit the shell, the stopped jobs are +sent a +.Dv HUP +signal and the shell exits. Similarly, if the +.Ic nohup +option is not set and there are running jobs when an attempt is made to exit +a login shell, the shell warns the user and does not exit. If another attempt +is immediately made to exit the shell, the running jobs are sent a +.Dv HUP +signal and the shell exits. +.Ss Emacs interactive input line editing +When the +.Ic emacs +option is set, interactive input line editing is enabled. Warning: This mode is +slightly different from the emacs mode in the original Korn shell and the 8th +bit is stripped in emacs mode. In this mode, various editing commands +(typically bound to one or more control characters) cause immediate actions +without waiting for a newline. Several editing commands are bound to particular +control characters when the shell is invoked; these binding can be changed using the following commands: -.\"{{{ bind -.IP \fBbind\fP +.Bl -tag -width Ds +.It Ic bind The current bindings are listed. -.\"}}} -.\"{{{ bind string=[editing-command] -.IP "\fBbind\fP \fIstring\fP\fB=\fP[\fIediting-command\fP]" -The specified editing command is bound to the given \fBstring\fP, which -should consist of a control character (which may be written using caret -notation \fB^\fP\fIX\fP), optionally preceded by one of the two prefix -characters. Future input of the \fIstring\fP will cause the editing -command to be immediately invoked. Note that although only two prefix -characters (usually ESC and ^X) are supported, some multi-character -sequences can be supported. The following binds the arrow keys on -an ANSI terminal, or xterm (these are in the default bindings). Of course -some escape sequences won't work out quite this nicely: -.sp -.RS -\fBbind '^[['=prefix\-2 -.br -bind '^XA'=up\-history -.br -bind '^XB'=down\-history -.br -bind '^XC'=forward\-char -.br -bind '^XD'=backward\-char\fP -.RE -.\"}}} -.\"{{{ bind -l -.IP "\fBbind \-l\fP" +.It Xo Ic bind +.Ar string Ns = Ns Op Ar editing-command +.Xc +The specified editing command is bound to the given +.Ar string , +which should consist of a control character (which may be written using caret +notation, i.e., ^X), optionally preceded by one of the two prefix characters. +Future input of the +.Ar string +will cause the editing command to be immediately invoked. Note that although +only two prefix characters (usually ESC and ^X) are supported, some +multi-character sequences can be supported. The following binds the arrow keys +on an ANSI terminal, or xterm (these are in the default bindings). Of course +some escape sequences won't work out quite this nicely. +.Pp +.Bl -item -compact +.It +.Ic bind '^[['=prefix-2 +.It +.Ic bind '^XA'=up-history +.It +.Ic bind '^XB'=down-history +.It +.Ic bind '^XC'=forward-char +.It +.Ic bind '^XD'=backward-char +.El +.It Ic bind Fl l Lists the names of the functions to which keys may be bound. -.\"}}} -.\"{{{ bind -m string=[substitute] -.IP "\fBbind \-m\fP \fIstring\fP\fB=\fP[\fIsubstitute\fP]" -The specified input \fIstring\fP will afterwards be immediately -replaced by the given \fIsubstitute\fP string, which may contain -editing commands. -.\"}}} -.PP -The following is a list of editing commands available. -Each description starts with the name of the command, -a \fIn\fP, if the command can be prefixed with a count, -and any keys the command is bound to by default (written using -caret notation, \fIe.g.\fP, ASCII ESC character is written as ^[). -A count prefix for a command is entered using the sequence -\fB^[\fP\fIn\fP, where \fIn\fP is a sequence of 1 or more digits; -unless otherwise specified, if a count is omitted, it defaults to 1. -Note that editing command names are -used only with the \fBbind\fP command. Furthermore, many editing -commands are useful only on terminals with a visible cursor. The -default bindings were chosen to resemble corresponding EMACS key -bindings. The users tty characters (\fIe.g.\fP, ERASE) are bound to +.It Xo Ic bind Fl m +.Sm off +.Ar string No = Op Ar substitute +.Sm on +.Xc +The specified input +.Ar string +will afterwards be immediately replaced by the given +.Ar substitute +string, which may contain editing commands. +.El +.Pp +The following is a list of available editing commands. Each description starts +with the name of the command, an +.Ar n +(if the command can be prefixed with a count), and any keys the command is +bound to by default (written using caret notation, i.e., ASCII ESC character is +written as ^[). A count prefix for a command is entered using the sequence +.Ic ^\&[ Ns Ar n , +where +.Ar n +is a sequence of 1 or more digits; unless otherwise specified, if a count is +omitted, it defaults to 1. Note that editing command names are used only with +the +.Ic bind +command. Furthermore, many editing commands are useful only on terminals with +a visible cursor. The default bindings were chosen to resemble corresponding +Emacs key bindings. The users' tty characters (e.g., ERASE) are bound to reasonable substitutes and override the default bindings. -.\"{{{ abort ^G -.IP "\fBabort ^G\fP" -Useful as a response to a request for a \fBsearch-history\fP pattern in -order to abort the search. -.\"}}} -.\"{{{ auto-insert n -.IP "\fBauto-insert\fP \fIn\fP" -Simply causes the character to appear as literal input. Most ordinary +.Bl -tag -width Ds +.It Ic abort ^G +Useful as a response to a request for a +.Ic search-history +pattern in order to about the search. +.It Ic auto-insert Ar n +Simply causes the character to appear as literal input. Most ordinary characters are bound to this. -.\"}}} -.\"{{{ backward-char n ^B -.IP "\fBbackward-char\fP \fIn\fP \fB^B\fP" -Moves the cursor backward \fIn\fP characters. -.\"}}} -.\"{{{ backward-word n ^[B -.IP "\fBbackward-word\fP \fIn\fP \fB^[B\fP" -Moves the cursor backward to the beginning of a word; words consist -of alphanumerics, underscore (_) and dollar ($). -.\"}}} -.\"{{{ beginning-of-history ^[< -.IP "\fBbeginning-of-history ^[<\fP" +.It Ic backward-char Ar n Ic ^B +Moves the cursor backward +.Ar n +characters. +.It Ic backward-word Ar n Ic ^[B +Moves the cursor backward to the beginning of the word; words consist of +alphanumerics, underscore +.Pq Sq _ +and dollar sign +.Pq Sq $ +characters. +.It Ic beginning-of-history ^[< Moves to the beginning of the history. -.\"}}} -.\"{{{ beginning-of-line ^A -.IP "\fBbeginning-of-line ^A\fP" +.It Ic beginning-of-line ^A Moves the cursor to the beginning of the edited input line. -.\"}}} -.\"{{{ capitalize-word n ^[c, ^[C -.IP "\fBcapitalize-word\fP \fIn\fP \fB^[c\fP, \fB^[C\fP" -Uppercase the first character in the next \fIn\fP words, -leaving the cursor past the end of the last word. -.\"}}} -.\"{{{ comment ^[# -If the current line does not begin with a comment character, one -is added at the beginning of the line and the line is entered (as if -return had been pressed), otherwise the existing comment characters -are removed and the cursor is placed at the beginning of the line. -.\"}}} -.\"{{{ complete ^[^[ -.IP "\fBcomplete ^[^[\fP" -Automatically completes as much as is unique of the command name -or the file name containing the cursor. If the entire remaining command -or file name is unique a space is printed after its completion, unless -it is a directory name in which case \fB/\fP is appended. If there is -no command or file name with the current partial word as its -prefix, a bell character is output (usually causing a audio beep). -.\"}}} -.\"{{{ complete-command ^X^[ -.IP "\fBcomplete-command ^X^[\fP" -Automatically completes as much as is unique of the command name -having the partial word up to the cursor as its prefix, as in the -\fBcomplete\fP command described above. -.\"}}} -.\"{{{ complete-file ^[^X -.IP "\fBcomplete-file ^[^X\fP" -Automatically completes as much as is unique of the file name having -the partial word up to the cursor as its prefix, as in the -\fBcomplete\fP command described above. -.\"}}} -.\"{{{ complete-list ^[= -.IP "\fBcomplete-list ^[=\fP" +.It Ic capitalize-word Ar n Ic ^[c , ^[C +Uppercase the first character in the next +.Ar n +words, leaving the cursor past the end of the last word. +.Pp +If the current line does not being with a comment character, one is added at +the beginning of the line and the line is entered (as if return had been +pressed), otherwise the existing comment characters are removed and the cursor +is placed at the beginning of the line. +.It Ic complete ^[^[ +Automatically completes as much as is unique of the command name or the file +name containing the cursor. If the entire remaining command or file name is +unique, a space is printed after its completion, unless it is a directory name +in which case +.Dq / +is appended. If there is no command or file name with the current partialword +as its prefix, a bell character is output (usually causing a beep to be +sounded). +.It Ic complete-command ^X^[ +Automatically completes as much as is unique of the command name having the +partial word up to the cursor as its prefix, as in the +.Ic complete +command above. +.It Ic complete-file ^[^X +Automatically completes as much as is unique of the file name having the +partial word up to the cursor as its prefix, as in the +.Ic complete +command described above. +.It Ic complete-list ^[= List the possible completions for the current word. -.\"}}} -.\"{{{ delete-char-backward n ERASE, ^?, ^H -.IP "\fBdelete-char-backward\fP \fIn\fP \fBERASE\fP, \fB^?\fP, \fB^H\fP" -Deletes \fIn\fP characters before the cursor. -.\"}}} -.\"{{{ delete-char-forward n -.IP "\fBdelete-char-forward\fP \fIn\fP" -Deletes \fIn\fP characters after the cursor. -.\"}}} -.\"{{{ delete-word-backward n ^[ERASE, ^[^?, ^[^H, ^[h -.IP "\fBdelete-word-backward\fP \fIn\fP \fB^[ERASE\fP, \fB^[^?\fP, \fB^[^H\fP, \fB^[h\fP" -Deletes \fIn\fP words before the cursor. -.\"}}} -.\"{{{ delete-word-forward n ^[d -.IP "\fBdelete-word-forward\fP \fIn\fP \fB^[d\fP" -Deletes characters after the cursor up to the end of \fIn\fP words. -.\"}}} -.\"{{{ down-history n ^N -.IP "\fBdown-history\fP \fIn\fP \fB^N\fP" -Scrolls the history buffer forward \fIn\fP lines (later). Each input line -originally starts just after the last entry in the history buffer, so -\fBdown-history\fP is not useful until either \fBsearch-history\fP or -\fBup-history\fP has been performed. -.\"}}} -.\"{{{ downcase-word n ^[L, ^[l -.IP "\fBdowncase-word\fP \fIn\fP \fB^[L\fP, \fB^[l\fP" -Lowercases the next \fIn\fP words. -.\"}}} -.\"{{{ end-of-history ^[> -.IP "\fBend-of-history ^[>\fP" +.It Xo Ic delete-char-backward Ar n Ic ERASE , +.Ic ^? , ^H +.Xc +Deletes +.Ar n +characters before the cursor. +.It Ic delete-char-forward Ar n +Deletes +.Ar n +characters after the cursor. +.It Xo Ic delete-word-backward Ar n Ic ^[ERASE , +.Ic ^[^? , ^[^H , ^[h +.Xc +Deletes +.Ar n +words before the cursor. +.It Ic delete-word-forward Ar n Ic ^[d +Deletes characters after the cursor up to the end of +.Ar n +words. +.It Ic down-history Ar n Ic ^N +Scrolls the history buffer forward +.Ar n +lines (later). Each input line originally starts just after the last entry +in the history buffer, so +.Ic down-history +is not useful until either +.Ic search-history +or +.Ic up-history +has been performed. +.It Ic downcase-word Ar n Ic ^[L , ^[l +Lowercases the next +.Ar n +words. +.It Ic end-of-history ^[> Moves to the end of the history. -.\"}}} -.\"{{{ end-of-line ^E -.IP "\fBend-of-line ^E\fP" +.It Ic end-of-line ^E Moves the cursor to the end of the input line. -.\"}}} -.\"{{{ eot ^_ -.IP "\fBeot ^_\fP" +.It Ic eot ^_ Acts as an end-of-file; this is useful because edit-mode input disables normal terminal input canonicalization. -.\"}}} -.\"{{{ eot-or-delete n ^D -.IP "\fBeot-or-delete\fP \fIn\fP \fB^D\fP" -Acts as eot if alone on a line; otherwise acts as delete-char-forward. -.\"}}} -.\"{{{ error -.IP "\fBerror\fP" +.It Ic eot-or-delete Ar n Ic ^D +Acts as +.Ic eot +if alone on a line; otherwise acts as +.Ic delete-char-forward . +.It Ic error Error (ring the bell). -.\"}}} -.\"{{{ exchange-point-and-mark ^X^X -.IP "\fBexchange-point-and-mark ^X^X\fP" -Places the cursor where the mark is, and sets the mark to where the -cursor was. -.\"}}} -.\"{{{ expand-file ^[* -.IP "\fBexpand-file ^[*\fP" -Appends a * to the current word and replaces the word with -the result of performing file globbing on the word. -If no files match the pattern, the bell is rung. -.\"}}} -.\"{{{ forward-char n ^F -.IP "\fBforward-char\fP \fIn\fP \fB^F\fP" -Moves the cursor forward \fIn\fP characters. -.\"}}} -.\"{{{ forward-word n ^[f -.IP "\fBforward-word\fP \fIn\fP \fB^[f\fP" -Moves the cursor forward to the end of the \fIn\fPth word. -.\"}}} -.\"{{{ goto-history n ^[g -.IP "\fBgoto-history\fP \fIn\fP \fB^[g\fP" -Goes to history number \fIn\fP. -.\"}}} -.\"{{{ kill-line KILL -.IP "\fBkill-line KILL\fP" +.It Ic exchange-point-and-mark ^X^X +Places the cursor where the mark is and sets the mark to where the cursor was. +.It Ic expand-file ^[\&* +Appends a +.Dq \&* +to the current word and replaces the word with the result of performing file +globbing on the word. If no files match the pattern, the bell is rung. +.It Ic forward-char Ar n Ic ^F +Moves the cursor forward +.Ar n +characters. +.It Ic forward-word Ar n Ic ^[f +Moves the cursor forward to the end of the +.Ar n Ns th +word. +.It Ic goto-history Ar n Ic ^[g +Goes to history number +.Ar n . +.It Ic kill-line KILL Deletes the entire input line. -.\"}}} -.\"{{{ kill-region ^W -.IP "\fBkill-region ^W\fP" +.It Ic kill-region ^W Deletes the input between the cursor and the mark. -.\"}}} -.\"{{{ kill-to-eol n ^K -.IP "\fBkill-to-eol\fP \fIn\fP \fB^K\fP" -Deletes the input from the cursor to the end of the line if \fIn\fP is -not specified, otherwise deletes characters between the cursor and -column \fIn\fP. -.\"}}} -.\"{{{ list ^[? -.IP "\fBlist ^[?\fP" -Prints a sorted, columnated list of command names or file names -(if any) that can complete the partial word containing the cursor. -Directory names have \fB/\fP appended to them. -.\"}}} -.\"{{{ list-command ^X? -.IP "\fBlist-command ^X?\fP" -Prints a sorted, columnated list of command names (if any) that -can complete the partial word containing the cursor. -.\"}}} -.\"{{{ list-file ^X^Y -.IP "\fBlist-file ^X^Y\fP" -Prints a sorted, columnated list of file names (if any) that can -complete the partial word containing the cursor. File type indicators -are appended as described under \fBlist\fP above. -.\"}}} -.\"{{{ newline ^J and ^M -.IP "\fBnewline ^J\fP, \fB^M\fP" -Causes the current input line to be processed by the shell. The -current cursor position may be anywhere on the line. -.\"}}} -.\"{{{ newline-and-next ^O -.IP "\fBnewline-and-next ^O\fP" -Causes the current input line to be processed by the shell, and -the next line from history becomes the current line. This is -only useful after an up-history or search-history. -.\"}}} -.\"{{{ no-op QUIT -.IP "\fBno-op QUIT\fP" +.It Ic kill-to-eol Ar n Ic ^K +Deletes the input from the cursor to the end of the line if +.Ar n +is not specified; otherwise deletes characters between the cursor and column +.Ar n . +.It Ic list ^[? +Prints a sorted, columnated list of command named or file names (if any) that +can complete the partial word containing the cursor. Directoary names have +.Dq / +appended to them. +.It Ic list-command ^X? +Prints a sorted, columnated list of command names (if any) that can complete +the partial word containg the cursor. +.It Ic list-file ^X^Y +Prints a sorted, comunated list of file names (if any) that can complete the +partial word containing the cursor. File type indicators are appended as +described under +.Ic list +above. +.It Ic newline ^J , ^M +Causes the current input line to be processed by the shell. The current cursor +position may be anywhere on the line. +.It Ic newline-and-next ^O +Causes the current input line to be processed by the shell, and the next line +from history becomes the current line. This is only useful after an +.Ic up-history +or +.ic search-history . +.It Ic no-op QUIT This does nothing. -.\"}}} -.\"{{{ prefix-1 ^[ -.IP "\fBprefix-1 ^[\fP" +.It Ic prefix-1 ^[ Introduces a 2-character command sequence. -.\"}}} -.\"{{{ prefix-2 ^X and ^[[ -.IP "\fBprefix-2 ^X\fP" -.IP "\fBprefix-2 ^[[\fP" +.It Ic prefix-2 ^X +.It Ic prefix-2 ^[[ Introduces a 2-character command sequence. -.\"}}} -.\"{{{ prev-hist-word ^[. ^[_ -.IP "\fBprev-hist-word\fP \fIn\fP \fB^[.\fP, \fB^[_\fP" -The last (\fIn\fPth) word of the previous command is inserted at the cursor. -.\"}}} -.\"{{{ quote ^^ -.IP "\fBquote ^^\fP" -The following character is taken literally rather than as an editing -command. -.\"}}} -.\"{{{ redraw ^L -.IP "\fBredraw ^L\fP" +.It Ic prev-hist-word Ar n Ic ^[\&. , ^{_ +The last +.Pq Ar n Ns th +word of the previous command is inserted at the cursor. +.It Ic quote ^^ +The following character is taken literally rather than as an editing command. +.It Ic redrew ^L Reprints the prompt string and the current input line. -.\"}}} -.\"{{{ search-character-backward n ^[^] -.IP "\fBsearch-character-backward\fP \fIn\fP \fB^[^]\fP" -Search backward in the current line for the \fIn\fPth occurance of the -next character typed. -.\"}}} -.\"{{{ search-character-forward n ^] -.IP "\fBsearch-character-forward\fP \fIn\fP \fB^]\fP" -Search forward in the current line for the \fIn\fPth occurance of the -next character typed. -.\"}}} -.\"{{{ search-history ^R -.IP "\fBsearch-history ^R\fP" -Enter incremental search mode. The internal history list is searched -backwards for commands matching the input. An initial \fB^\fP in the -search string anchors the search. The abort key will leave search mode. -Other commands will be executed after leaving search mode. Successive -\fBsearch-history\fP commands continue searching backward to the next -previous occurrence of the pattern. The history buffer retains only a -finite number of lines; the oldest are discarded as necessary. -.\"}}} -.\"{{{ set-mark-command ^[<space> -.IP "\fBset-mark-command ^[\fP<space>" +.It Ic search-character-backward Ar n Ic ^[^] +Search backward in the current line for the +.Ar n Ns th +occurrence of the next character typed. +.It Ic search-character-forward Ar n Ic ^] +Search forward in the current line for the +.Ar n Ns th +occurrence of the next character typed. +.It Ic search-history ^R +Enter incremental search mode. The internal history list is searched +backwards for commands matching the input. An initial +.Dq ^ +in the search string anchors the search. The abort key will leave search mode. +Other commands will be executed after leaving search mode. Successive +.Ic search-history +commands continue searching backward to the next previous occurrence of the +pattern. The history buffer retains only a finite number of lines; the oldest +are discarded as necessary. +.It Ic set-mark-command ^[ Ns No <space> Set the mark at the cursor position. -.\"}}} -.\"{{{ stuff -.IP "\fBstuff\fP" -On systems supporting it, pushes the bound character back onto the -terminal input where it may receive special processing by the terminal -handler. This is useful for the BRL \fB^T\fP mini-systat feature, for -example. -.\"}}} -.\"{{{ stuff-reset -.IP "\fBstuff-reset\fP" -Acts like \fBstuff\fP, then aborts input the same as an interrupt. -.\"}}} -.\"{{{ transport-chars ^T -.IP "\fBtranspose-chars ^T\fP" -If at the end of line, or if the \fBgmacs\fP option is set, -this exchanges the two previous characters; otherwise, it -exchanges the previous and current characters and moves the cursor -one character to the right. -.\"}}} -.\"{{{ up-history n ^P -.IP "\fBup-history\fP \fIn\fP \fB^P\fP" -Scrolls the history buffer backward \fIn\fP lines (earlier). -.\"}}} -.\"{{{ upcase-word n ^[U, ^[u -.IP "\fBupcase-word\fP \fIn\fP \fB^[U\fP, \fB^[u\fP" -Uppercases the next \fIn\fP words. -.\"}}} -.\"{{{ version ^V -.IP "\fBversion ^V\fP" -Display the version of ksh. The current edit buffer is restored as soon -as any key is pressed (the key is then processed, unless it is a space). -.\"}}} -.\"{{{ yank ^Y -.IP "\fByank ^Y\fP" +.It Ic stuff +On systems supporting it, puhses the bound character back onto the terminal +input where it may receive special processing by the terminal handler. This +is useful for the BRL ^T mini-systat feature, for example. +.It Ic stuff-reset +Acts like +.Ic stuff , +then aborts input the same as an interrupt. +.It Ic transpose-chars ^T +If at the end of line, or if the +.Ic gmacs +option is set, this exchanges the two previous characters; otherwise, it +exchanges the previous and current characters and moves the cursor one +character to the right. +.It Ic up-history Ar n Ic ^P +Scrolls the history buffer backward +.Ar n +lines (earlier). +.It Ic upcase-word Ar n Ic ^[U , ^[u +Uppercase the next +.Ar n +words. +.It Ic version ^V +Display the version of ksh. The current edit buffer is restored as soon as any +key is pressed (the key is then processed, unless it is a space). +.It Ic yank ^Y Inserts the most recently killed text string at the current cursor position. -.\"}}} -.\"{{{ yank-pop ^[y -.IP "\fByank-pop ^[y\fP" -Immediately after a \fByank\fP, replaces the inserted text string with -the next previous killed text string. -.\"}}} -.\"}}} -.\"{{{ Vi Interactive Input Line Editing -.\"{{{ introduction -.SS "Vi Interactive Input Line Editing" -The vi command line editor in ksh has basically the same commands as the -vi editor (see \fIvi\fP(1)), with the following exceptions: -.nr P2 \n(PD -.IP \ \ \(bu -you start out in insert mode, -.IP \ \ \(bu -there are file name and command completion commands -(\fB=\fP, \fB\e\fP, \fB*\fP, \fB^X\fP, \fB^E\fP, \fB^F\fP and, -optionally, \fB<tab>\fP), -.IP \ \ \(bu -the \fB_\fP command is different (in ksh it is the last argument command, -in vi it goes to the start of the current line), -.IP \ \ \(bu -the \fB/\fP and \fBG\fP commands move in the opposite direction as the \fBj\fP -command -.IP \ \ \(bu -and commands which don't make sense in a single line editor are not available -(\fIe.g.\fP, screen movement commands, ex \fB:\fP commands, \fIetc.\fP). -.nr PD \n(P2 -.LP -Note that the \fB^X\fP stands for control-X; also \fB<esc>\fP, \fB<space>\fP -and \fB<tab>\fP are used for escape, space and tab, respectively (no kidding). -.\"}}} -.\"{{{ modes -.PP -Like vi, there are two modes: insert mode and command mode. -In insert mode, most characters are simply put in the buffer at the -current cursor position as they are typed, however, some characters -are treated specially. -In particular, the following characters are taken from current tty settings -(see \fIstty\fP(1)) and have their usual meaning (normal values are in -parentheses): -kill (\fB^U\fP), erase (\fB^?\fP), werase (\fB^W\fP), eof (\fB^D\fP), -intr (\fB^C\fP) and quit (\fB^\e\fP). -In addition to the above, the following characters are also treated -specially in insert mode: -.TS -expand; -afB lw(4.5i). -^H T{ -erases previous character -T} -^V T{ -literal next: the next character typed is not treated specially (can be -used to insert the characters being described here) -T} -^J ^M T{ -end of line: the current line is read, parsed and executed by the shell -T} -<esc> T{ -puts the editor in command mode (see below) -T} -^E T{ -command and file name enumeration (see below) -T} -^F T{ -command and file name completion (see below). -If used twice in a row, the list of possible completions is displayed; -if used a third time, the completion is undone. -T} -^X T{ -command and file name expansion (see below) -T} -<tab> T{ -optional file name and command completion (see \fB^F\fP above), enabled with -\fBset \-o vi-tabcomplete\fP -T} -.TE -.\"}}} -.\"{{{ display -.PP -If a line is longer that the screen width (see \fBCOLUMNS\fP parameter), -a \fB>\fP, \fB+\fP or \fB<\fP character is displayed in the last column -indicating that there are more characters after, before and after, or -before the current position, respectively. -The line is scrolled horizontally as necessary. -.\"}}} -.\"{{{ command mode -.PP -In command mode, each character is interpreted as a command. -Characters that don't correspond to commands, are illegal combinations of -commands or are commands that can't be carried out all cause beeps. -In the following command descriptions, a \fIn\fP indicates the -command may be prefixed by a number (\fIe.g.\fP, \fB10l\fP moves right 10 -characters); if no number prefix is used, \fIn\fP is assumed to be 1 -unless otherwise specified. -The term `current position' refers to the position between the cursor -and the character preceding the cursor. -A `word' is a sequence of letters, digits and underscore characters or a -sequence of non-letter, non-digit, non-underscore, non-white-space characters -(\fIe.g.\fP, ab2*&^ contains two words) and a `big-word' is a sequence of -non-white-space characters. -.\"{{{ Special ksh vi commands -.IP "Special ksh vi commands" +.It Ic yank-pop ^[y +Immediately after a +.Ic yank , +replaces the inserted text string with the next previously killed text string. +.El +.Ss Vi interactive input line editing +The vi command line editor in ksh has basically the same commands as the vi +editor (see +.Xr vi 1 ) , +with the following exceptions: +.Bl -bullet +.It +You start out in insert mode. +.It +There are file name and command completion commands +.Po +.Ic = , \e , \&* , ^X , +.Ic ^E , ^F , +and, optionally, +.Ic <tab> +.Pc . +.It +The +.Ic _ +command is different (in ksh it is the last argument command, in vi it goes to +the start of the current line). +.It +The +.Ic / +and +.Ic G +commands move in the opposite direction as the +.Ic j +command. +.it +Commands which don't make sense in a single line editor are not available +(e.g., screen movement command, ex-style +.Ic \&: +commands, etc.). +.El +.Pp +Note that the ^X stands for control-X; also <esc>, <space> and <tab> are used +for escape, space, and tab, respectively (no kidding). +.Pp +Like vi, there are two modes -- +.Dq insert +mode and +.Dq command +mode. In insert mode, most characters are simply put in the buffer at the +current cursor position as they are typed, however, some characters are +treated specially. In particular, the following characters are taken from +current tty settings (see +.Xr tty 1 ) +and have their usual meaning (normal values are in parentheses): kill (^U), +erase (^?), werase (^W), eof (^D), intr (^C), and quit (^\e). In addition to +the above, the following characters are also treated specially in insert mode: +.Bl -tag -width 10n +.It Ic ^H +Erases previous character. +.It Ic ^V +Liternal next. The next character typed is not treated specially (can be used +to insert the characters being described here). +.It Ic ^J ^M +End of line. The current line is read, parsed and executed by the shell. +.It Ic <esc> +Puts the editor in command mode (see below). +.It Ic ^E +Command and file name enumeration (see below). +.It Ic ^F +Command and file name completion (see below). If used twice in a row, the +list of possible completions is displayed; if used a third time, the completion +is undone. +.It Ic ^X +Command and file name expansion (see below). +.It Ic <tab> +Optional file name and command completion (see +.Ic ^F +above), enabled with +.Ic set Fl o Ic vi-tabcomplete . +.El +.Pp +If a line is longer than the screen width (see +.Dv COLUMNS +parameter), a +.Dq \&> , +.Dq \&+ +or +.Dq \&< +character is displayed in the last column indicating that there are more +characters after, before and after, or before the current position, +respectively. The line is scrolled horizontally as necessary. +.Pp +In command mode, each character is interpreted as a command. Characters that +don't correspond to commands, are illegal combinations of commands, or are +commands that can't be carried out all cause beeps. In the following command +descriptions, an +.Ar n +indicates the command may be prefixed by a number (e.g., +.Ic 10l +moves right 10 characters); if no number prefix is used, +.Ar n +is assumed to be 1 unless otherwise specified. The term +.Dq current position +refers to the position between the cursor and the character preceding the +cursor. A +.Dq word +is a sequence of letters, digits and underscore characters or a sequence of +non-letter, non-digit, non-underscore, non-whitespace characters (e.g., +.Dq ab2\&*\&&^ +contains two words) and a +.Dq big-word +is a sequence of non-whitespace characters. +.Pp +Special ksh vi commands +.Pp The following commands are not in, or are different from, the normal vi file editor: -.RS -.IP "\fIn\fP\fB_\fP" -insert a space followed by the \fIn\fPth big-word from the last command in the -history at the current position and enter insert mode; if \fIn\fP is not -specified, the last word is inserted. -.IP "\fB#\fP" -insert the comment character (\fB#\fP) at the start of the current line and -return the line to the shell (equivalent to \fBI#^J\fP). -.IP "\fIn\fP\fBg\fP" -like \fBG\fP, except if \fIn\fP is not specified, it goes to the most recent -remembered line. -.IP "\fIn\fP\fBv\fP" -edit line \fIn\fP using the vi editor; -if \fIn\fP is not specified, the current line is edited. -The actual command executed is -`\fBfc \-e ${VISUAL:-${EDITOR:-vi}}\fP \fIn\fP'. -.IP "\fB*\fP and \fB^X\fP" -command or file name expansion is applied to the current big-word -(with an appended *, if the word contains no file globing characters) - the -big-word is replaced with the resulting words. -If the current big-word is the first on the line (or follows one -of the following characters: \fB;\fP, \fB|\fP, \fB&\fP, \fB(\fP, \fB)\fP) -and does not contain a slash (\fB/\fP) then command expansion is done, -otherwise file name expansion is done. -Command expansion will match the big-word against all aliases, functions -and built-in commands as well as any executable files found by searching -the directories in the \fBPATH\fP parameter. -File name expansion matches the big-word against the files in the -current directory. -After expansion, the cursor is placed just past the last word and the editor -is in insert mode. -.IP "\fIn\fP\fB\e\fP, \fIn\fP\fB^F\fP, \fIn\fP\fB<tab>\fP and \fIn\fP\fB<esc>\fP" -command/file name completion: -replace the current big-word with the longest unique -match obtained after performing command/file name expansion. -\fB<tab>\fP is only recognized if the \fBvi-tabcomplete\fP option is set, -while \fB<esc>\fP is only recognized if the \fBvi-esccomplete\fP option -is set (see \fBset \-o\fP). -If \fIn\fP is specified, the \fIn\fPth possible -completion is selected (as reported by the command/file name enumeration -command). -.IP "\fB=\fP and \fB^E\fP" -command/file name enumeration: list all the commands or files that match -the current big-word. -.IP "\fB^V\fP" -display the version of pdksh; it is displayed until another key is pressed -(this key is ignored). -.IP "\fB@\fP\fIc\fP" -macro expansion: execute the commands found in the alias _\fIc\fP. -.RE -.\"}}} -.\"{{{ Intra-line movement commands -.IP "Intra-line movement commands" -.RS -.IP "\fIn\fP\fBh\fP and \fIn\fP\fB^H\fP" -move left \fIn\fP characters. -.IP "\fIn\fP\fBl\fP and \fIn\fP\fB<space>\fP" -move right \fIn\fP characters. -.IP "\fB0\fP" -move to column 0. -.IP "\fB^\fP" -move to the first non white-space character. -.IP "\fIn\fP\fB|\fP" -move to column \fIn\fP. -.IP "\fB$\fP" -move to the last character. -.IP "\fIn\fP\fBb\fP" -move back \fIn\fP words. -.IP "\fIn\fP\fBB\fP" -move back \fIn\fP big-words. -.IP "\fIn\fP\fBe\fP" -move forward to the end the word, \fIn\fP times. -.IP "\fIn\fP\fBE\fP" -move forward to the end the big-word, \fIn\fP times. -.IP "\fIn\fP\fBw\fP" -move forward \fIn\fP words. -.IP "\fIn\fP\fBW\fP" -move forward \fIn\fP big-words. -.IP "\fB%\fP" -find match: the editor looks forward for the nearest parenthesis, -bracket or brace and then moves the to the matching parenthesis, bracket or -brace. -.IP "\fIn\fP\fBf\fP\fIc\fP" -move forward to the \fIn\fPth occurrence of the character \fIc\fP. -.IP "\fIn\fP\fBF\fP\fIc\fP" -move backward to the \fIn\fPth occurrence of the character \fIc\fP. -.IP "\fIn\fP\fBt\fP\fIc\fP" -move forward to just before the \fIn\fPth occurrence of the character \fIc\fP. -.IP "\fIn\fP\fBT\fP\fIc\fP" -move backward to just before the \fIn\fPth occurrence of the character \fIc\fP. -.IP "\fIn\fP\fB;\fP" -repeats the last \fBf\fP, \fBF\fP, \fBt\fP or \fBT\fP command. -.IP "\fIn\fP\fB,\fP" -repeats the last \fBf\fP, \fBF\fP, \fBt\fP or \fBT\fP command, but moves -in the opposite direction. -.RE -.\"}}} -.\"{{{ Inter-line movement commands -.IP "Inter-line movement commands" -.RS -.IP "\fIn\fP\fBj\fP and \fIn\fP\fB+\fP and \fIn\fP\fB^N\fP" -move to the \fIn\fPth next line in the history. -.IP "\fIn\fP\fBk\fP and \fIn\fP\fB-\fP and \fIn\fP\fB^P\fP" -move to the \fIn\fPth previous line in the history. -.IP "\fIn\fP\fBG\fP" -move to line \fIn\fP in the history; if \fIn\fP is not specified, the -number first remembered line is used. -.IP "\fIn\fP\fBg\fP" -like \fBG\fP, except if \fIn\fP is not specified, it goes to the most recent -remembered line. -.IP "\fIn\fP\fB/\fP\fIstring\fP" -search backward through the history for the \fIn\fPth line containing -\fIstring\fP; if \fIstring\fP starts with \fB^\fP, the remainder of the -string must appear at the start of the history line for it to match. -.IP "\fIn\fP\fB?\fP\fIstring\fP" -same as \fB/\fP, except it searches forward through the history. -.IP "\fIn\fP\fBn\fP" -search for the \fIn\fPth occurrence of the last search string; the -direction of the search is the same as the last search. -.IP "\fIn\fP\fBN\fP" -search for the \fIn\fPth occurrence of the last search string; the -direction of the search is the opposite of the last search. -.RE -.\"}}} -.\"{{{ Edit commands -.IP "Edit commands" -.RS -.IP "\fIn\fP\fBa\fP" -append text \fIn\fP times: goes into insert mode just after the current -position. -The append is only replicated if command mode is re-entered (\fIi.e.\fP, -<esc> is used). -.IP "\fIn\fP\fBA\fP" -same as \fBa\fP, except it appends at the end of the line. -.IP "\fIn\fP\fBi\fP" -insert text \fIn\fP times: goes into insert mode at the current -position. -The insertion is only replicated if command mode is re-entered (\fIi.e.\fP, -<esc> is used). -.IP "\fIn\fP\fBI\fP" -same as \fBi\fP, except the insertion is done just before the first non-blank -character. -.IP "\fIn\fP\fBs\fP" -substitute the next \fIn\fP characters (\fIi.e.\fP, delete the characters -and go into insert mode). -.IP "\fBS\fP" -substitute whole line: all characters from the first non-blank character -to the end of line are deleted and insert mode is entered. -.IP "\fIn\fP\fBc\fP\fImove-cmd\fP" -change from the current position to the position resulting from \fIn\fP -\fImove-cmd\fPs (\fIi.e.\fP, delete the indicated region and go into insert -mode); -if \fImove-cmd\fP is \fBc\fP, the line starting from the first non-blank -character is changed. -.IP "\fBC\fP" -change from the current position to the end of the line (\fIi.e.\fP, delete to -the end of the line and go into insert mode). -.IP "\fIn\fP\fBx\fP" -delete the next \fIn\fP characters. -.IP "\fIn\fP\fBX\fP" -delete the previous \fIn\fP characters. -.IP "\fBD\fP" -delete to the end of the line. -.IP "\fIn\fP\fBd\fP\fImove-cmd\fP" -delete from the current position to the position resulting from -\fIn\fP \fImove-cmd\fPs; -\fImove-cmd\fP is a movement command (see above) or \fBd\fP, in which case -the current line is deleted. -.IP "\fIn\fP\fBr\fP\fIc\fP" -replace the next \fIn\fP characters with the character \fIc\fP. -.IP "\fIn\fP\fBR\fP" -replace: enter insert mode but overwrite existing characters instead of -inserting before existing characters. The replacement is repeated \fIn\fP +.Bl -tag -width 10n +.It Ar n Ns _ +Insert a space followed by the +.Ar n Ns th +big-word from the last command in the history at the current position and enter +insert mode; if +.Ar n +is not specified, the last word is inserted. +.It Ic \&# +Insert the comment character +.Pq Sq # +at the start of the current line and return the line to the shell (equivalent +to +.Ic \&I#^J ) . +.It Ar n Ns Ic g +Like +.Ic G , +except if +.Ar n +is not specified, it goes to the most recent remembered line. +.It Ic Ar n Ns Ic v +Edit line +.Ar n +using the vi editor; if +.Ar n +is not specified, the current line is edited. The actual command executed is +.Ic fc Fl e Ic ${VISUAL;-${EDITOR:-vi}} Ar n . +.It Ic \&* No and Ic ^X +Command or file name expansion is applied to the current big-word (with an +appended +.Dq \&* , +if the word contains no file globbing characters) -- the big-word is replaced +with the resulting words. If the current big-word is the first on the line (or +follows one of the following characters: +.Dq \&; , +.Dq \&| , +.Dq \&& , +.Dq \&( , +or +.Dq \&) ) +and does not contain a slash +.Pq Sq / +then the command expansion is done; otherwise file name expansion is done. +Command expansion will match the big-word against all aliases, functions and +built-in commands as well as any executable files found by searching the +directories in the +.Ev PATH +parameter. File name expansion matches the big-word against the files in the +current directory. After expansion, the cursor is places just past the last +word and the editor is in insert mode. +.It n\e,\ n^F,\ n<tab>,\ and\ n<esc> +Command/file name completion. Replace the current big-word with the +longest unique match obtained after performing command and file name expansion. +.Ic <tab> +is only recognized if the +.Ic vi-tabcomplete +option is set, while +.Ic <esc> +is only recognized if the +.Ic vi-esccomplete +option is set (see +.Ic set Fl o ) . +If +.Ar n +is specified, the +.Ar n Ns th +possible completion is selected (as reported by the command/file name +enumeration command). +.It Ic \&= No and Ic ^E +Command/file name enumeration. List all the commands or files that match the +current big-word. +.It Ic ^V +Display the version of +.Nm pdksh ; +it is displayed until another key is pressed (this key is ignored). +.It Ic @ Ns Ar c +Macro expansion. Execute the commands found in the alias +.Ar c . +.El +.Pp +Intra-line movement commands: +.Bl -tag -width Ds +.It Xo Ar n Ns Ic h No and +.Ar n Ns Ic ^H +.Xc +Move left +.Ar n +characters. +.It Xo Ar n Ns Ic l No and +.Ar n Ns Ic <space> +.Xc +Move right +.Ar n +characters. +.It Ic \&0 +Move to column 0. +.It Ic ^ +Move to the first non-whitespace character. +.It Ar n Ns Ic \&| +Move to column +.Ar n . +.It Ic $ +Move to the last character. +.It Ar n Ns Ic b +Move back +.Ar n +words. +.It Ar n Ns Ic B +Move back +.Ar n +big-words. +.It Ar n Ns Ic e +Move forward to the end of the word, +.Ar n +times. +.It Ar n Ns Ic E +Move forward to the end of the big-word, +.Ar n +times. +.It Ar n Ns Ic w +Move forward +.Ar n +words. +.It Ar n Ns Ic W +Move forward +.Ar n +big-words. +.It Ic % +Find match. The editor looks forward for the nearest parenthesis, bracket or +brace and then moves the cursor to the matching parenthesis, bracket or brace. +.It Ar n Ns Ic f Ns Ar c +Move forward to the +.Ar n Ns th +occurrence of the character +.Ar c . +.It Ar n Ns Ic F Ns Ar c +Move backward to the +.Ar n Ns th +occurrence of the character +.Ar c . +.It Ar n Ns Ic t Ns Ar c +Move forward to just before the +.Ar n Ns th +occurrence of the character +.Ar c . +.It Ar n Ns Ic T Ns Ar c +Move backward to just before the +.Ar n Ns th +occurrence of the character +.Ar c . +.It Ar n Ns Ic \&; +Repeats the last +.Ic f , F , t +or +.Ic T +command. +.It Ar n Ns Ic \&, +Repeats the last +.Ic f , F , t +or +.Ic T +command, but moves in the opposite direction. +.El +.Pp +Inter-line movement commands: +.Bl -tag -width Ds +.It nj,\ n+\ and\ n^N +Move to the +.Ar n Ns th +next line in the history. +.It nk,\ n-\ and\ n^P +Move to the +.Ar n Ns th +previous line in the history. +.It Ar n Ns Ic G +Move to line +.Ar n +in the history; if +.Ar n +is not specified, the number of the first remembered line is used. +.It Ar n Ns Ic g +Like +.Ic G , +except if +.Ar n +is not specified, it goes to the most recent remembered line. +.It Ar n Ns Ic / Ns Ar string +Search backward through the history for the +.Ar n Ns th +line containing +.Ar string ; +if +.Ar string +starts with +.Dq ^ , +the remainder of the string must appear at the start of the history line for +it to match. +.It Ar n Ns Ic \&? Ns Ar string +Same as +.Ic / , +except it searches forward through the history. +.It Ar n Ns Ic n +Search for the +.Ar n Ns th +occurrence of the last search string; the directory of the search is the same +as the last search. +.It Ar n Ns Ic N +Search for the +.Ar n Ns th +occurrence of the last search string; the directory of the search is the +opposite of the last search. +.El +.Pp +Edit commands +.Bl -tag -width Ds +.It Ar n Ns Ic a +Append text +.Ar n +times; goes into insert mode just after the current position. The append is +only replicated if command mode is re-entered (i.e., <esc> is used). +.It Ar n Ns Ic A +Same as +.Ic a , +except it appends at the end of the line. +.It Ar n Ns Ic i +Insert text +.Ar n +times; goes into insert mode at the current position. The insertion is only +replicated if command mode is re-entered (i.e., <esc> is used). +.It Ar n Ns Ic I +Same as +.Ic i , +except the insertion is done just before the first non-blank character. +.It Ar n Ns Ic s +Substitute the next +.Ar n +characters (i.e., delete the characters and go into insert mode). +.It Ic S +Substitute whole line. All characters from the first non-blank character to the +end of the line are deleted and insert mode is entered. +.It Ar n Ns Ic c Ns Ar move-cmd +Change from the current position to the position resulting from +.Ar n move-cmd Ns s +(i.e., delete the indicated region and go into insert mode); if +.Ar move-cmd +is +.Ic c , +the line starting from the first non-blank character is changed. +.It Ic C +Change from the current position to the end of the line (i.e., delete to the +end of the line and go into insert mode). +.It Ar n Ns Ic x +Delete the next +.Ar n +characters. +.It Ar n Ns Ic X +Delete the previous +.Ar n +characters. +.It Ic D +Delete to the end of the line. +.It Ar n Ns Ic d Ns Ar move-cmd +Delete from the current position to the position resulting from +.Ar n move-cmd Ns s ; +.Ar move-cmd +is a movement command (see above) or +.Ic d , +in which case the current line is deleted. +.It Ar n Ns Ic r Ns Ar c +Replace the next +.Ar n +characters with the character +.Ar c . +.It Ar n Ns Ic R +Replace. Enter insert mode but overwrite existing characters instead of +inserting before existing characters. The replacement is repeated +.Ar n +times. +.It Ar n Ns Ic \&~ +Change the case of the next +.Ar n +characters. +.It Ar n Ns Ic y Ns Ar move-cmd +Yank from the current position to the position resulting from +.Ar n move-cmd Ns s +into the yank buffer; if +.Ar move-cmd +is +.Ic y , +the whole line is yanked. +.It Ic Y +Yank from the current position to the end of the line. +.It Ar n Ns Ic p +Paste the contents of the yank buffer just after the current position, +.Ar n +times. +.It Ar n Ns Ic P +Same as +.Ic p , +except the buffer is pasted at the current position. +.El +.Pp +Miscellaneous vi commands +.Pp +.Bl -tag -width Ds +.It Ic ^J No and Ic ^M +The current line is read, parsed and executed by the shell. +.It Ic ^L No and Ic ^R +Redraw the current line. +.It Ar n Ns Ic \&. +Redo the last edit command +.Ar n times. -.IP "\fIn\fP\fB~\fP" -change the case of the next \fIn\fP characters. -.IP "\fIn\fP\fBy\fP\fImove-cmd\fP" -yank from the current position to the position resulting from \fIn\fP -\fImove-cmd\fPs into the yank buffer; if \fImove-cmd\fP is \fBy\fP, the -whole line is yanked. -.IP "\fBY\fP" -yank from the current position to the end of the line. -.IP "\fIn\fP\fBp\fP" -paste the contents of the yank buffer just after the current position, -\fIn\fP times. -.IP "\fIn\fP\fBP\fP" -same as \fBp\fP, except the buffer is pasted at the current position. -.RE -.\"}}} -.\"{{{ Miscellaneous vi commands -.IP "Miscellaneous vi commands" -.RS -.IP "\fB^J\fP and \fB^M\fP" -the current line is read, parsed and executed by the shell. -.IP "\fB^L\fP and \fB^R\fP" -redraw the current line. -.IP "\fIn\fP\fB.\fP" -redo the last edit command \fIn\fP times. -.IP "\fBu\fP" -undo the last edit command. -.IP "\fBU\fP" -undo all changes that have been made to the current line. -.IP "\fIintr\fP and \fIquit\fP" -the interrupt and quit terminal characters cause the current line to -be deleted and a new prompt to be printed. -.RE -.\"Has all vi commands except: -.\" movement: { } [[ ]] ^E ^Y ^U ^D ^F ^B H L M () -.\" tag commands: ^T ^] -.\" mark commands: m ` ' -.\" named-buffer commands: " @ -.\" file/shell/ex-commands: Q ZZ ^^ : ! & -.\" multi-line change commands: o O J -.\" shift commands: << >> -.\" status command: ^G -.\"}}} -.\"}}} -.\"}}} -.\"}}} -.\"{{{ Files -.SH FILES -~/.profile -.br -/etc/profile -.br -/etc/suid_profile -.\"}}} -.\"{{{ Bugs -.SH BUGS -Any bugs in pdksh should be reported to pdksh@cs.mun.ca. Please -include the version of pdksh (echo $KSH_VERSION shows it), the machine, -operating system and compiler you are using and a description of how to -repeat the bug (a small shell script that demonstrates the bug is -best). The following, if relevant (if you are not sure, include them), -can also helpful: options you are using (both options.h options and set -\-o options) and a copy of your config.h (the file generated by the -configure script). New versions of pdksh can be obtained from -ftp://ftp.cs.mun.ca/pub/pdksh/. -.\"}}} -.\"{{{ Authors -.SH AUTHORS +.It Ic u +Undo the last edit command. +.It Ic U +Undo all changes that have been made to the current line. +.It Ar intr No and Ar quit +The interrupt and quit terminal characters cause the current line to be +deleted and a new prompt to be printed. +.Sh FILES +.Bl -tag -width "/etc/suid_profile" -compact +.It Pa ~/.profile +.It Pa /etc/profile +.It Pa /etc/suid_profile +.El +.Sh SEE ALSO +.Xr awk 1 , +.Xr csh 1 , +.Xr ed 1 , +.Xr getconf 1 , +.Xr getopt 1 , +.Xr sed 1 , +.Xr sh 1 , +.Xr stty 1 , +.Xr vi 1 , +.Xr dup 2 , +.Xr execve 2 , +.Xr getgid 2 , +.Xr getuid 2 , +.Xr open 2 , +.Xr pipe 2 , +.Xr wait 2 , +.Xr getopt 3 , +.Xr rand 3 , +.Xr signal 3 , +.Xr system 3 , +.Xr environ 5 +.Pp +.Rs +.%A Morris Bolsky and David Korn +.%T "The KornShell Command and Programming Language" +.%D 1983 +.%O "ISBN 0-13-516972-0" +.Re +.Rs +.%A Stephen G. Kochan and Patrick H. Wood +.%T "UNIX Shell Programming" +.%O "Hayden" +.Re +.Rs +.%A "IEEE Inc." +.%T "IEEE Standard for Information Technology - Portable Operating System Interface (POSIX) - Part 2: Shell and Utilities" +.%D 1993 +.%O "ISBN 1-55937-266-9" +.Re +.Sh BUGS +Any bugs in +.Nm pdksh +should be reported to pdksh@cs.mun.ca. Please include the version of +.Nm pdksh +.Po +.Ic echo $KSH_VERSION +shows it +.Pc , +the machine, operating system and compiler you are using and a description of +how to repeat the bug (a small shell script that demonstrates the bug is best). +The following, if relevant (if you are not sure, include them), can also be +helpful: options you are using (both +.Pa options.h +and +.Ic set Fl o Ic options ) +and a copy of your +.Pa config.h +(the file generated by the +.Pa configure +script). New version of +.Nm pdksh +can be obtained from ftp://ftp.cs.mun.ca/pub/pdksh. +.Sh AUTHORS This shell is based on the public domain 7th edition Bourne shell clone by -Charles Forsyth and parts of the BRL shell by Doug A.\& Gwyn, Doug Kingston, -Ron Natalie, Arnold Robbins, Lou Salkind and others. The first release -of pdksh was created by Eric Gisin, and it was subsequently maintained by -John R.\& MacMillan (chance!john@sq.sq.com), and -Simon J.\& Gerraty (sjg@zen.void.oz.au). The current maintainer is -Michael Rendell (michael@cs.mun.ca). -The CONTRIBUTORS file in the source distribution contains a more complete -list of people and their part in the shell's development. -.\"}}} -.\"{{{ See also -.SH "SEE ALSO" -awk(1), -sh(1), -csh(1), ed(1), getconf(1), getopt(1), sed(1), stty(1), vi(1), -dup(2), execve(2), getgid(2), getuid(2), open(2), pipe(2), wait(2), -getopt(3), rand(3), signal(3), system(3), -environ(5) -.PP -.IR "The KornShell Command and Programming Language" , -Morris Bolsky and David Korn, 1989, ISBN 0-13-516972-0. -.PP -.\" XXX ISBN missing -.IR "UNIX Shell Programming" , -Stephen G.\& Kochan, Patrick H.\& Wood, Hayden. -.PP -.IR "IEEE Standard for information Technology \- Portable Operating System Interface (POSIX) \- Part 2: Shell and Utilities" , -IEEE Inc, 1993, ISBN 1-55937-255-9. -.\"}}} +Charles Forsyth and parts of the BRL shell by Doug A. Gwyn, Doug Kingston, +Ron Natalie, Arnold Robbins, Lou Salkind, and others. The first release of +.Nm pdksh +was created by Eric Gisin, and it was subsequently maintained by John R. +MacMillan (change!john@sq.sq.com) and Simon J. Gerraty (sjg@zen.void.oz.au). +The current maintainer is Michael Rendell (michael@cs.mun.ca). The +.Pa CONTRIBUTORS +file in the source distribution contains a more complete list of people and +their part in the shell's development. |