initial import of NetBSD tree

2 files changed, 3739 insertions, 0 deletions

diff --git a/usr.bin/make/PSD.doc/Makefile b/usr.bin/make/PSD.doc/Makefile
new file mode 100644
index 00000000000..8e1f1fa0705
--- /dev/null
+++ b/usr.bin/make/PSD.doc/Makefile
@@ -0,0 +1,8 @@
+#	$NetBSD: Makefile,v 1.2 1995/06/14 15:20:23 christos Exp $
+#	@(#)Makefile	8.1 (Berkeley) 8/14/93
+
+DIR=	psd/12.make
+SRCS=	tutorial.ms
+MACROS=	-ms
+
+.include <bsd.doc.mk>
diff --git a/usr.bin/make/PSD.doc/tutorial.ms b/usr.bin/make/PSD.doc/tutorial.ms
new file mode 100644
index 00000000000..84237218a5e
--- /dev/null
+++ b/usr.bin/make/PSD.doc/tutorial.ms
@@ -0,0 +1,3731 @@
+.\"	$NetBSD: tutorial.ms,v 1.2 1995/06/14 15:20:31 christos Exp $
+.\" Copyright (c) 1988, 1989 by Adam de Boor
+.\" Copyright (c) 1989 by Berkeley Softworks
+.\" Copyright (c) 1988, 1989, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Adam de Boor.
+.\"
+.\" 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.
+.\"
+.\"	@(#)tutorial.ms	8.1 (Berkeley) 8/18/93
+.\"
+.EH 'PSD:12-%''PMake \*- A Tutorial'
+.OH 'PMake \*- A Tutorial''PSD:12-%'
+.\" xH is a macro to provide numbered headers that are automatically stuffed
+.\" into a table-of-contents, properly indented, etc. If the first argument
+.\" is numeric, it is taken as the depth for numbering (as for .NH), else
+.\" the default (1) is assumed.
+.\"
+.\" @P The initial paragraph distance.
+.\" @Q The piece of section number to increment (or 0 if none given)
+.\" @R Section header.
+.\" @S Indent for toc entry
+.\" @T Argument to NH (can't use @Q b/c giving 0 to NH resets the counter)
+.de xH
+.NH \\$1
+\\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
+.nr PD .1v
+.XS \\n%
+.ta 0.6i
+\\*(SN	\\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
+.XE
+.nr PD .3v
+..
+.\" CW is used to place a string in fixed-width or switch to a
+.\" fixed-width font.
+.\" C is a typewriter font for a laserwriter. Use something else if
+.\" you don't have one...
+.de CW
+.ie !\\n(.$ .ft C
+.el \&\\$3\fC\\$1\fP\\$2
+..
+.\" Anything I put in a display I want to be in fixed-width
+.am DS
+.CW
+..
+.\" The stuff in .No produces a little stop sign in the left margin
+.\" that says NOTE in it. Unfortunately, it does cause a break, but
+.\" hey. Can't have everything. In case you're wondering how I came
+.\" up with such weird commands, they came from running grn on a
+.\" gremlin file...
+.de No
+.br
+.ne 0.5i
+.po -0.5i
+.br
+.mk 
+.nr g3 \\n(.f
+.nr g4 \\n(.s
+.sp -1
+.\" .st cf
+\D's -1u'\D't 5u'
+.sp -1
+\h'50u'\D'l 71u 0u'\D'l 50u 50u'\D'l 0u 71u'\D'l -50u 50u'\D'l -71u 0u'\D'l -50u -50u'\D'l 0u -71u'\D'l 50u -50u'
+.sp -1
+\D't 3u'
+.sp -1
+.sp 7u
+\h'53u'\D'p 14 68u 0u 46u 46u 0u 68u -46u 46u -68u 0u -47u -46u 0u -68u 47u -46u'
+.sp -1
+.ft R
+.ps 6
+.nr g8 \\n(.d
+.ds g9 "NOTE
+.sp 74u
+\h'85u'\v'0.85n'\h-\w\\*(g9u/2u\&\\*(g9
+.sp |\\n(g8u
+.sp 166u
+\D't 3u'\D's -1u'
+.br
+.po
+.rt 
+.ft \\n(g3
+.ps \\n(g4
+..
+.de Bp
+.ie !\\n(.$ .IP \(bu 2
+.el .IP "\&" 2
+..
+.po +.3i
+.TL
+PMake \*- A Tutorial
+.AU
+Adam de Boor
+.AI
+Berkeley Softworks
+2150 Shattuck Ave, Penthouse
+Berkeley, CA 94704
+adam@bsw.uu.net
+\&...!uunet!bsw!adam
+.FS
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appears in all copies.
+The University of California, Berkeley Softworks, and Adam de Boor make no
+representations about the suitability of this software for any
+purpose.  It is provided "as is" without express or implied warranty.
+.FE
+.PP
+.xH 1 Introduction
+.LP
+PMake is a program for creating other programs, or anything else you
+can think of for it to do.  The basic idea behind PMake is that, for
+any given system, be it a program or a document or whatever, there
+will be some files that depend on the state of other files (on when
+they were last modified). PMake takes these dependencies, which you
+must specify, and uses them to build whatever it is you want it to
+build.
+.LP
+PMake is almost fully-compatible with Make, with which you may already
+be familiar. PMake's most important feature is its ability to run
+several different jobs at once, making the creation of systems
+considerably faster. It also has a great deal more functionality than
+Make. Throughout the text, whenever something is mentioned that is an
+important difference between PMake and Make (i.e.  something that will
+cause a makefile to fail if you don't do something about it), or is
+simply important, it will be flagged with a little sign in the left
+margin, like this:
+.No
+.LP
+This tutorial is divided into three main sections corresponding to basic,
+intermediate and advanced PMake usage. If you already know Make well,
+you will only need to skim chapter 2 (there are some aspects of
+PMake that I consider basic to its use that didn't exist in Make).
+Things in chapter 3 make life much easier, while those in chapter 4
+are strictly for those who know what they are doing. Chapter 5 has
+definitions for the jargon I use and chapter 6 contains possible
+solutions to the problems presented throughout the tutorial.
+.xH 1 The Basics of PMake
+.LP
+PMake takes as input a file that tells a) which files depend on which
+other files to be complete and b) what to do about files that are
+``out-of-date.'' This file is known as a ``makefile'' and is usually
+.Ix 0 def makefile
+kept in the top-most directory of the system to be built. While you
+can call the makefile anything you want, PMake will look for
+.CW Makefile
+and
+.CW makefile
+(in that order) in the current directory if you don't tell it
+otherwise.
+.Ix 0 def makefile default
+To specify a different makefile, use the
+.B \-f
+flag (e.g.
+.CW "pmake -f program.mk" ''). ``
+.Ix 0 ref flags -f
+.Ix 0 ref makefile other
+.LP
+A makefile has four different types of lines in it:
+.RS
+.IP \(bu 2
+File dependency specifications
+.IP \(bu 2
+Creation commands
+.IP \(bu 2
+Variable assignments
+.IP \(bu 2
+Comments, include statements and conditional directives
+.RE
+.LP
+Any line may be continued over multiple lines by ending it with a
+backslash.
+.Ix 0 def "continuation line"
+The backslash, following newline and any initial whitespace
+on the following line are compressed into a single space before the
+input line is examined by PMake.
+.xH 2 Dependency Lines
+.LP
+As mentioned in the introduction, in any system, there are
+dependencies between the files that make up the system.  For instance,
+in a program made up of several C source files and one header file,
+the C files will need to be re-compiled should the header file be
+changed. For a document of several chapters and one macro file, the
+chapters will need to be reprocessed if any of the macros changes.
+.Ix 0 def "dependency"
+These are dependencies and are specified by means of dependency lines in
+the makefile.
+.LP
+.Ix 0 def "dependency line"
+On a dependency line, there are targets and sources, separated by a
+one- or two-character operator.
+The targets ``depend'' on the sources and are usually created from
+them.
+.Ix 0 def target
+.Ix 0 def source
+.Ix 0 ref operator
+Any number of targets and sources may be specified on a dependency line.
+All the targets in the line are made to depend on all the sources.
+Targets and sources need not be actual files, but every source must be
+either an actual file or another target in the makefile.
+If you run out of room, use a backslash at the end of the line to continue onto
+the next one.
+.LP
+Any file may be a target and any file may be a source, but the
+relationship between the two (or however many) is determined by the
+``operator'' that separates them.
+.Ix 0 def operator
+Three types of operators exist: one specifies that the datedness of a
+target is determined by the state of its sources, while another
+specifies other files (the sources) that need to be dealt with before
+the target can be re-created. The third operator is very similar to
+the first, with the additional condition that the target is
+out-of-date if it has no sources. These operations are represented by
+the colon, the exclamation point and the double-colon, respectively, and are
+mutually exclusive. Their exact semantics are as follows:
+.IP ":"
+.Ix 0 def operator colon
+.Ix 0 def :
+If a colon is used, a target on the line is considered to be
+``out-of-date'' (and in need of creation) if 
+.RS
+.IP \(bu 2
+any of the sources has been modified more recently than the target, or
+.IP \(bu 2
+the target doesn't exist.
+.RE
+.Ix 0 def out-of-date
+.IP "\&"
+Under this operation, steps will be taken to re-create the target only
+if it is found to be out-of-date by using these two rules.
+.IP "!"
+.Ix 0 def operator force
+.Ix 0 def !
+If an exclamation point is used, the target will always be re-created,
+but this will not happen until all of its sources have been examined
+and re-created, if necessary.
+.IP "::"
+.Ix 0 def operator double-colon
+.Ix 0 def ::
+If a double-colon is used, a target is out-of-date if:
+.RS
+.IP \(bu 2
+any of the sources has been modified more recently than the target, or
+.IP \(bu 2
+the target doesn't exist, or
+.IP \(bu 2
+the target has no sources.
+.RE
+.IP "\&"
+If the target is out-of-date according to these rules, it will be re-created.
+This operator also does something else to the targets, but I'll go
+into that in the next section (``Shell Commands'').
+.LP
+Enough words, now for an example. Take that C program I mentioned
+earlier. Say there are three C files
+.CW a.c , (
+.CW b.c
+and
+.CW  c.c )
+each of which
+includes the file
+.CW defs.h .
+The dependencies between the files could then be expressed as follows:
+.DS
+program         : a.o b.o c.o
+a.o b.o c.o     : defs.h
+a.o             : a.c
+b.o             : b.c
+c.o             : c.c
+.DE
+.LP
+You may be wondering at this point, where
+.CW a.o ,
+.CW b.o
+and
+.CW c.o
+came in and why
+.I they
+depend on
+.CW defs.h
+and the C files don't. The reason is quite simple:
+.CW program
+cannot be made by linking together .c files \*- it must be
+made from .o files. Likewise, if you change
+.CW defs.h ,
+it isn't the .c files that need to be re-created, it's the .o files.
+If you think of dependencies in these terms \*- which files (targets)
+need to be created from which files (sources) \*- you should have no problems.
+.LP
+An important thing to notice about the above example, is that all the
+\&.o files appear as targets on more than one line. This is perfectly
+all right: the target is made to depend on all the sources mentioned
+on all the dependency lines. E.g.
+.CW a.o
+depends on both
+.CW defs.h
+and
+.CW a.c .
+.Ix 0 ref dependency
+.No
+.LP
+The order of the dependency lines in the makefile is
+important: the first target on the first dependency line in the
+makefile will be the one that gets made if you don't say otherwise.
+That's why
+.CW program
+comes first in the example makefile, above.
+.LP
+Both targets and sources may contain the standard C-Shell wildcard
+characters
+.CW { , (
+.CW } ,
+.CW * ,
+.CW ? ,
+.CW [ ,
+and
+.CW ] ),
+but the non-curly-brace ones may only appear in the final component
+(the file portion) of the target or source. The characters mean the
+following things:
+.IP \fB{}\fP
+These enclose a comma-separated list of options and cause the pattern
+to be expanded once for each element of the list. Each expansion
+contains a different element. For example, 
+.CW src/{whiffle,beep,fish}.c
+expands to the three words
+.CW src/whiffle.c ,
+.CW src/beep.c ,
+and 
+.CW src/fish.c .
+These braces may be nested and, unlike the other wildcard characters,
+the resulting words need not be actual files. All other wildcard
+characters are expanded using the files that exist when PMake is
+started.
+.IP \fB*\fP
+This matches zero or more characters of any sort. 
+.CW src/*.c
+will expand to the same three words as above as long as 
+.CW src
+contains those three files (and no other files that end in 
+.CW .c ).
+.IP \fB?\fP
+Matches any single character.
+.IP \fB[]\fP
+This is known as a character class and contains either a list of
+single characters, or a series of character ranges 
+.CW a-z , (
+for example means all characters between a and z), or both. It matches
+any single character contained in the list. E.g.
+.CW [A-Za-z]
+will match all letters, while
+.CW [0123456789]
+will match all numbers.
+.xH 2 Shell Commands
+.LP
+``Isn't that nice,'' you say to yourself, ``but how are files
+actually `re-created,' as he likes to spell it?''
+The re-creation is accomplished by commands you place in the makefile.
+These commands are passed to the Bourne shell (better known as
+``/bin/sh'') to be executed and are
+.Ix 0 ref shell
+.Ix 0 ref re-creation
+.Ix 0 ref update
+expected to do what's necessary to update the target file (PMake
+doesn't actually check to see if the target was created. It just
+assumes it's there).
+.Ix 0 ref target
+.LP
+Shell commands in a makefile look a lot like shell commands you would
+type at a terminal, with one important exception: each command in a
+makefile
+.I must
+be preceded by at least one tab.
+.LP
+Each target has associated with it a shell script made up of
+one or more of these shell commands. The creation script for a target
+should immediately follow the dependency line for that target. While
+any given target may appear on more than one dependency line, only one
+of these dependency lines may be followed by a creation script, unless
+the `::' operator was used on the dependency line.
+.Ix 0 ref operator double-colon
+.Ix 0 ref ::
+.No
+.LP
+If the double-colon was used, each dependency line for the target
+may be followed by a shell script. That script will only be executed
+if the target on the associated dependency line is out-of-date with
+respect to the sources on that line, according to the rules I gave
+earlier.
+I'll give you a good example of this later on.
+.LP
+To expand on the earlier makefile, you might add commands as follows:
+.DS
+program         : a.o b.o c.o
+        cc a.o b.o c.o \-o program
+a.o b.o c.o     : defs.h
+a.o             : a.c
+        cc \-c a.c
+b.o             : b.c
+        cc \-c b.c
+c.o             : c.c
+        cc \-c c.c
+.DE
+.LP
+Something you should remember when writing a makefile is, the
+commands will be executed if the
+.I target
+on the dependency line is out-of-date, not the sources.
+.Ix 0 ref target
+.Ix 0 ref source
+.Ix 0 ref out-of-date
+In this example, the command
+.CW "cc \-c a.c" '' ``
+will be executed if
+.CW a.o
+is out-of-date. Because of the `:' operator,
+.Ix 0 ref :
+.Ix 0 ref operator colon
+this means that should
+.CW a.c
+.I or
+.CW defs.h
+have been modified more recently than
+.CW a.o ,
+the command will be executed
+.CW a.o "\&" (
+will be considered out-of-date).
+.Ix 0 ref out-of-date
+.LP
+Remember how I said the only difference between a makefile shell
+command and a regular shell command was the leading tab? I lied. There
+is another way in which makefile commands differ from regular ones.
+The first two characters after the initial whitespace are treated
+specially.
+If they are any combination of `@' and `\-', they cause PMake to do
+different things.
+.LP
+In most cases, shell commands are printed before they're
+actually executed. This is to keep you informed of what's going on. If
+an `@' appears, however, this echoing is suppressed. In the case of an
+.CW echo
+command, say
+.CW "echo Linking index" ,'' ``
+it would be
+rather silly to see
+.DS
+echo Linking index
+Linking index
+.DE
+.LP
+so PMake allows you to place an `@' before the command
+.CW "@echo Linking index" '') (``
+to prevent the command from being printed.
+.LP
+The other special character is the `\-'. In case you didn't know,
+shell commands finish with a certain ``exit status.'' This status is
+made available by the operating system to whatever program invoked the
+command. Normally this status will be 0 if everything went ok and
+non-zero if something went wrong. For this reason, PMake will consider
+an error to have occurred if one of the shells it invokes returns a non-zero
+status. When it detects an error, PMake's usual action is to abort
+whatever it's doing and exit with a non-zero status itself (any other
+targets that were being created will continue being made, but nothing
+new will be started. PMake will exit after the last job finishes).
+This behavior can be altered, however, by placing a `\-' at the front
+of a command
+.CW "\-mv index index.old" ''), (``
+certain command-line arguments,
+or doing other things, to be detailed later. In such
+a case, the non-zero status is simply ignored and PMake keeps chugging
+along.
+.No
+.LP
+Because all the commands are given to a single shell to execute, such
+things as setting shell variables, changing directories, etc., last
+beyond the command in which they are found. This also allows shell
+compound commands (like
+.CW for
+loops) to be entered in a natural manner.
+Since this could cause problems for some makefiles that depend on
+each command being executed by a single shell, PMake has a
+.B \-B
+.Ix 0 ref compatibility
+.Ix 0 ref flags -B
+flag (it stands for backwards-compatible) that forces each command to
+be given to a separate shell. It also does several other things, all
+of which I discourage since they are now old-fashioned.\|.\|.\|.
+.No
+.LP
+A target's shell script is fed to the shell on its (the shell's) input stream.
+This means that any commands, such as
+.CW ci
+that need to get input from the terminal won't work right \*- they'll
+get the shell's input, something they probably won't find to their
+liking. A simple way around this is to give a command like this:
+.DS
+ci $(SRCS) < /dev/tty
+.DE
+This would force the program's input to come from the terminal. If you
+can't do this for some reason, your only other alternative is to use
+PMake in its fullest compatibility mode. See 
+.B Compatibility
+in chapter 4.
+.Ix 0 ref compatibility
+.LP
+.xH 2 Variables
+.LP
+PMake, like Make before it, has the ability to save text in variables
+to be recalled later at your convenience. Variables in PMake are used
+much like variables in the shell and, by tradition, consist of
+all upper-case letters (you don't
+.I have
+to use all upper-case letters.
+In fact there's nothing to stop you from calling a variable
+.CW @^&$%$ .
+Just tradition). Variables are assigned-to using lines of the form
+.Ix 0 def variable assignment
+.DS
+VARIABLE = value
+.DE
+.Ix 0 def variable assignment
+appended-to by
+.DS
+VARIABLE += value
+.DE
+.Ix 0 def variable appending
+.Ix 0 def variable assignment appended
+.Ix 0 def +=
+conditionally assigned-to (if the variable isn't already defined) by
+.DS
+VARIABLE ?= value
+.DE
+.Ix 0 def variable assignment conditional
+.Ix 0 def ?=
+and assigned-to with expansion (i.e. the value is expanded (see below)
+before being assigned to the variable\*-useful for placing a value at
+the beginning of a variable, or other things) by
+.DS
+VARIABLE := value
+.DE
+.Ix 0 def variable assignment expanded
+.Ix 0 def :=
+.LP
+Any whitespace before
+.I value
+is stripped off. When appending, a space is placed between the old
+value and the stuff being appended.
+.LP
+The final way a variable may be assigned to is using
+.DS
+VARIABLE != shell-command
+.DE
+.Ix 0 def variable assignment shell-output
+.Ix 0 def !=
+In this case, 
+.I shell-command
+has all its variables expanded (see below) and is passed off to a
+shell to execute. The output of the shell is then placed in the
+variable. Any newlines (other than the final one) are replaced by
+spaces before the assignment is made. This is typically used to find
+the current directory via a line like:
+.DS
+CWD             != pwd
+.DE
+.LP
+.B Note:
+this is intended to be used to execute commands that produce small amounts
+of output (e.g. ``pwd''). The implementation is less than intelligent and will
+likely freeze if you execute something that produces thousands of
+bytes of output (8 Kb is the limit on many UNIX systems).
+.LP
+The value of a variable may be retrieved by enclosing the variable
+name in parentheses or curly braces and preceeding the whole thing
+with a dollar sign.
+.LP
+For example, to set the variable CFLAGS to the string
+.CW "\-I/sprite/src/lib/libc \-O" ,'' ``
+you would place a line
+.DS
+CFLAGS = \-I/sprite/src/lib/libc \-O
+.DE
+in the makefile and use the word
+.CW "$(CFLAGS)"
+wherever you would like the string
+.CW "\-I/sprite/src/lib/libc \-O"
+to appear. This is called variable expansion.
+.Ix 0 def variable expansion
+.No
+.LP
+Unlike Make, PMake will not expand a variable unless it knows
+the variable exists. E.g. if you have a
+.CW "${i}"
+in a shell command and you have not assigned a value to the variable
+.CW i 
+(the empty string is considered a value, by the way), where Make would have
+substituted the empty string, PMake will leave the
+.CW "${i}"
+alone.
+To keep PMake from substituting for a variable it knows, precede the
+dollar sign with another dollar sign.
+(e.g. to pass
+.CW "${HOME}"
+to the shell, use
+.CW "$${HOME}" ).
+This causes PMake, in effect, to expand the
+.CW $
+macro, which expands to a single
+.CW $ .
+For compatibility, Make's style of variable expansion will be used
+if you invoke PMake with any of the compatibility flags (\c
+.B \-V ,
+.B \-B
+or
+.B \-M .
+The
+.B \-V
+flag alters just the variable expansion).
+.Ix 0 ref flags -V
+.Ix 0 ref flags -B
+.Ix 0 ref flags -M
+.Ix 0 ref compatibility
+.LP
+.Ix 0 ref variable expansion
+There are two different times at which variable expansion occurs:
+When parsing a dependency line, the expansion occurs immediately
+upon reading the line. If any variable used on a dependency line is
+undefined, PMake will print a message and exit.
+Variables in shell commands are expanded when the command is
+executed.
+Variables used inside another variable are expanded whenever the outer
+variable is expanded (the expansion of an inner variable has no effect
+on the outer variable. I.e. if the outer variable is used on a dependency
+line and in a shell command, and the inner variable changes value
+between when the dependency line is read and the shell command is
+executed, two different values will be substituted for the outer
+variable).
+.Ix 0 def variable types
+.LP
+Variables come in four flavors, though they are all expanded the same
+and all look about the same. They are (in order of expanding scope):
+.RS
+.IP \(bu 2
+Local variables.
+.Ix 0 ref variable local
+.IP \(bu 2
+Command-line variables.
+.Ix 0 ref variable command-line
+.IP \(bu 2
+Global variables.
+.Ix 0 ref variable global
+.IP \(bu 2
+Environment variables.
+.Ix 0 ref variable environment
+.RE
+.LP
+The classification of variables doesn't matter much, except that the
+classes are searched from the top (local) to the bottom (environment)
+when looking up a variable. The first one found wins.
+.xH 3 Local Variables
+.LP
+.Ix 0 def variable local
+Each target can have as many as seven local variables. These are
+variables that are only ``visible'' within that target's shell script
+and contain such things as the target's name, all of its sources (from
+all its dependency lines), those sources that were out-of-date, etc.
+Four local variables are defined for all targets. They are:
+.RS
+.IP ".TARGET"
+.Ix 0 def variable local .TARGET
+.Ix 0 def .TARGET
+The name of the target.
+.IP ".OODATE"
+.Ix 0 def variable local .OODATE
+.Ix 0 def .OODATE
+The list of the sources for the target that were considered out-of-date.
+The order in the list is not guaranteed to be the same as the order in
+which the dependencies were given.
+.IP ".ALLSRC"
+.Ix 0 def variable local .ALLSRC
+.Ix 0 def .ALLSRC
+The list of all sources for this target in the order in which they
+were given.
+.IP ".PREFIX"
+.Ix 0 def variable local .PREFIX
+.Ix 0 def .PREFIX
+The target without its suffix and without any leading path. E.g. for
+the target
+.CW ../../lib/compat/fsRead.c ,
+this variable would contain
+.CW fsRead .
+.RE
+.LP
+Three other local variables are set only for certain targets under
+special circumstances. These are the ``.IMPSRC,''
+.Ix 0 ref variable local .IMPSRC
+.Ix 0 ref .IMPSRC
+``.ARCHIVE,''
+.Ix 0 ref variable local .ARCHIVE
+.Ix 0 ref .ARCHIVE
+and ``.MEMBER''
+.Ix 0 ref variable local .MEMBER
+.Ix 0 ref .MEMBER
+variables. When they are set and how they are used is described later.
+.LP
+Four of these variables may be used in sources as well as in shell
+scripts.
+.Ix 0 def "dynamic source"
+.Ix 0 def source dynamic
+These are ``.TARGET'', ``.PREFIX'', ``.ARCHIVE'' and ``.MEMBER''. The
+variables in the sources are expanded once for each target on the
+dependency line, providing what is known as a ``dynamic source,''
+.Rd 0
+allowing you to specify several dependency lines at once. For example,
+.DS
+$(OBJS)         : $(.PREFIX).c
+.DE
+will create a dependency between each object file and its
+corresponding C source file.
+.xH 3 Command-line Variables
+.LP
+.Ix 0 def variable command-line
+Command-line variables are set when PMake is first invoked by giving a
+variable assignment as one of the arguments. For example,
+.DS
+pmake "CFLAGS = -I/sprite/src/lib/libc -O"
+.DE
+would make 
+.CW CFLAGS
+be a command-line variable with the given value. Any assignments to
+.CW CFLAGS
+in the makefile will have no effect, because once it
+is set, there is (almost) nothing you can do to change a command-line
+variable (the search order, you see). Command-line variables may be
+set using any of the four assignment operators, though only
+.CW =
+and
+.CW ?=
+behave as you would expect them to, mostly because assignments to
+command-line variables are performed before the makefile is read, thus
+the values set in the makefile are unavailable at the time.
+.CW +=
+.Ix 0 ref +=
+.Ix 0 ref variable assignment appended
+is the same as
+.CW = ,
+because the old value of the variable is sought only in the scope in
+which the assignment is taking place (for reasons of efficiency that I
+won't get into here).
+.CW :=
+and
+.CW ?=
+.Ix 0 ref :=
+.Ix 0 ref ?=
+.Ix 0 ref variable assignment expanded
+.Ix 0 ref variable assignment conditional
+will work if the only variables used are in the environment.
+.CW !=
+is sort of pointless to use from the command line, since the same
+effect can no doubt be accomplished using the shell's own command
+substitution mechanisms (backquotes and all that).
+.xH 3 Global Variables
+.LP
+.Ix 0 def variable global
+Global variables are those set or appended-to in the makefile.
+There are two classes of global variables: those you set and those PMake sets.
+As I said before, the ones you set can have any name you want them to have,
+except they may not contain a colon or an exclamation point.
+The variables PMake sets (almost) always begin with a
+period and always contain upper-case letters, only. The variables are
+as follows:
+.RS
+.IP .PMAKE
+.Ix 0 def variable global .PMAKE
+.Ix 0 def .PMAKE
+.Ix 0 def variable global MAKE
+.Ix 0 def MAKE
+The name by which PMake was invoked is stored in this variable. For
+compatibility, the name is also stored in the MAKE variable.
+.IP .MAKEFLAGS
+.Ix 0 def variable global .MAKEFLAGS
+.Ix 0 def .MAKEFLAGS variable
+.Ix 0 def variable global MFLAGS
+.Ix 0 def MFLAGS
+All the relevant flags with which PMake was invoked. This does not
+include such things as
+.B \-f
+or variable assignments. Again for compatibility, this value is stored
+in the MFLAGS variable as well.
+.RE
+.LP
+Two other variables, ``.INCLUDES'' and ``.LIBS,'' are covered in the
+section on special targets in chapter 3.
+.Ix 0 ref variable global .INCLUDES
+.Ix 0 ref variable global .LIBS
+.LP
+Global variables may be deleted using lines of the form:
+.Ix 0 def #undef
+.Ix 0 def variable deletion
+.DS
+#undef \fIvariable\fP
+.DE
+The
+.CW # ' `
+must be the first character on the line. Note that this may only be
+done on global variables.
+.xH 3 Environment Variables
+.LP
+.Ix 0 def variable environment
+Environment variables are passed by the shell that invoked PMake and
+are given by PMake to each shell it invokes. They are expanded like
+any other variable, but they cannot be altered in any way.
+.LP
+One special environment variable,
+.CW PMAKE ,
+.Ix 0 def variable environment PMAKE
+is examined by PMake for command-line flags, variable assignments,
+etc., it should always use. This variable is examined before the
+actual arguments to PMake are. In addition, all flags given to PMake,
+either through the
+.CW PMAKE
+variable or on the command line, are placed in this environment
+variable and exported to each shell PMake executes. Thus recursive
+invocations of PMake automatically receive the same flags as the
+top-most one.
+.LP
+Using all these variables, you can compress the sample makefile even more:
+.DS
+OBJS            = a.o b.o c.o
+program         : $(OBJS)
+        cc $(.ALLSRC) \-o $(.TARGET)
+$(OBJS)         : defs.h
+a.o             : a.c
+        cc \-c a.c
+b.o             : b.c
+        cc \-c b.c
+c.o             : c.c
+        cc \-c c.c
+.DE
+.Ix 0 ref variable local .ALLSRC
+.Ix 0 ref .ALLSRC
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref .TARGET
+.Rd 3
+.xH 2 Comments
+.LP
+.Ix 0 def comments
+Comments in a makefile start with a `#' character and extend to the
+end of the line. They may appear
+anywhere you want them, except in a shell command (though the shell
+will treat it as a comment, too). If, for some reason, you need to use the `#'
+in a variable or on a dependency line, put a backslash in front of it.
+PMake will compress the two into a single `#' (Note: this isn't true
+if PMake is operating in full-compatibility mode).
+.Ix 0 ref flags -M
+.Ix 0 ref compatibility
+.xH 2 Parallelism
+.No
+.LP
+PMake was specifically designed to re-create several targets at once,
+when possible. You do not have to do anything special to cause this to
+happen (unless PMake was configured to not act in parallel, in which
+case you will have to make use of the
+.B \-L
+and
+.B \-J
+flags (see below)),
+.Ix 0 ref flags -L
+.Ix 0 ref flags -J
+but you do have to be careful at times.
+.LP
+There are several problems you are likely to encounter. One is
+that some makefiles (and programs) are written in such a way that it is
+impossible for two targets to be made at once. The program
+.CW xstr ,
+for example,
+always modifies the files
+.CW strings
+and
+.CW x.c .
+There is no way to change it. Thus you cannot run two of them at once
+without something being trashed. Similarly, if you have commands
+in the makefile that always send output to the same file, you will not
+be able to make more than one target at once unless you change the
+file you use. You can, for instance, add a
+.CW $$$$
+to the end of the file name to tack on the process ID of the shell
+executing the command (each
+.CW $$
+expands to a single
+.CW $ ,
+thus giving you the shell variable
+.CW $$ ).
+Since only one shell is used for all the
+commands, you'll get the same file name for each command in the
+script.
+.LP
+The other problem comes from improperly-specified dependencies that
+worked in Make because of its sequential, depth-first way of examining
+them. While I don't want to go into depth on how PMake
+works (look in chapter 4 if you're interested), I will warn you that
+files in two different ``levels'' of the dependency tree may be
+examined in a different order in PMake than they were in Make. For
+example, given the makefile
+.DS
+a               : b c
+b               : d
+.DE
+PMake will examine the targets in the order
+.CW c ,
+.CW d ,
+.CW b ,
+.CW a .
+If the makefile's author expected PMake to abort before making
+.CW c
+if an error occurred while making
+.CW b ,
+or if
+.CW b
+needed to exist before
+.CW c
+was made,
+s/he will be sorely disappointed. The dependencies are
+incomplete, since in both these cases,
+.CW c
+would depend on
+.CW b .
+So watch out.
+.LP
+Another problem you may face is that, while PMake is set up to handle the
+output from multiple jobs in a graceful fashion, the same is not so for input.
+It has no way to regulate input to different jobs,
+so if you use the redirection from
+.CW /dev/tty
+I mentioned earlier, you must be careful not to run two of the jobs at once.
+.xH 2 Writing and Debugging a Makefile
+.LP
+Now you know most of what's in a makefile, what do you do next? There
+are two choices: (1) use one of the uncommonly-available makefile
+generators or (2) write your own makefile (I leave out the third choice of
+ignoring PMake and doing everything by hand as being beyond the bounds
+of common sense).
+.LP
+When faced with the writing of a makefile, it is usually best to start
+from first principles: just what
+.I are
+you trying to do? What do you want the makefile finally to produce?
+.LP
+To begin with a somewhat traditional example, let's say you need to
+write a makefile to create a program,
+.CW expr ,
+that takes standard infix expressions and converts them to prefix form (for
+no readily apparent reason). You've got three source files, in C, that
+make up the program:
+.CW main.c ,
+.CW parse.c ,
+and
+.CW output.c .
+Harking back to my pithy advice about dependency lines, you write the
+first line of the file:
+.DS
+expr            : main.o parse.o output.o
+.DE
+because you remember
+.CW expr
+is made from
+.CW .o
+files, not
+.CW .c
+files. Similarly for the
+.CW .o
+files you produce the lines:
+.DS
+main.o          : main.c
+parse.o         : parse.c
+output.o        : output.c
+main.o parse.o output.o : defs.h
+.DE
+.LP
+Great. You've now got the dependencies specified. What you need now is
+commands. These commands, remember, must produce the target on the
+dependency line, usually by using the sources you've listed.
+You remember about local variables? Good, so it should come
+to you as no surprise when you write
+.DS
+expr            : main.o parse.o output.o
+        cc -o $(.TARGET) $(.ALLSRC)
+.DE
+Why use the variables? If your program grows to produce postfix
+expressions too (which, of course, requires a name change or two), it
+is one fewer place you have to change the file. You cannot do this for
+the object files, however, because they depend on their corresponding
+source files
+.I and
+.CW defs.h ,
+thus if you said
+.DS
+	cc -c $(.ALLSRC)
+.DE
+you'd get (for
+.CW main.o ):
+.DS
+	cc -c main.c defs.h
+.DE
+which is wrong. So you round out the makefile with these lines:
+.DS
+main.o          : main.c
+        cc -c main.c
+parse.o         : parse.c
+        cc -c parse.c
+output.o        : output.c
+        cc -c output.c
+.DE
+.LP
+The makefile is now complete and will, in fact, create the program you
+want it to without unnecessary compilations or excessive typing on
+your part. There are two things wrong with it, however (aside from it
+being altogether too long, something I'll address in chapter 3):
+.IP 1)
+The string
+.CW "main.o parse.o output.o" '' ``
+is repeated twice, necessitating two changes when you add postfix
+(you were planning on that, weren't you?). This is in direct violation
+of de Boor's First Rule of writing makefiles:
+.QP
+.I
+Anything that needs to be written more than once
+should be placed in a variable.
+.IP "\&"
+I cannot emphasize this enough as being very important to the
+maintenance of a makefile and its program.
+.IP 2)
+There is no way to alter the way compilations are performed short of
+editing the makefile and making the change in all places. This is evil
+and violates de Boor's Second Rule, which follows directly from the
+first:
+.QP
+.I
+Any flags or programs used inside a makefile should be placed in a variable so
+they may be changed, temporarily or permanently, with the greatest ease.
+.LP
+The makefile should more properly read:
+.DS
+OBJS            = main.o parse.o output.o
+expr            : $(OBJS)
+        $(CC) $(CFLAGS) -o $(.TARGET) $(.ALLSRC)
+main.o          : main.c
+        $(CC) $(CFLAGS) -c main.c
+parse.o         : parse.c
+        $(CC) $(CFLAGS) -c parse.c
+output.o        : output.c
+        $(CC) $(CFLAGS) -c output.c
+$(OBJS)         : defs.h
+.DE
+Alternatively, if you like the idea of dynamic sources mentioned in
+section 2.3.1,
+.Rm 0 2.3.1
+.Rd 4
+.Ix 0 ref "dynamic source"
+.Ix 0 ref source dynamic
+you could write it like this:
+.DS
+OBJS            = main.o parse.o output.o
+expr            : $(OBJS)
+        $(CC) $(CFLAGS) -o $(.TARGET) $(.ALLSRC)
+$(OBJS)         : $(.PREFIX).c defs.h
+        $(CC) $(CFLAGS) -c $(.PREFIX).c
+.DE
+These two rules and examples lead to de Boor's First Corollary:
+.QP
+.I
+Variables are your friends.
+.LP
+Once you've written the makefile comes the sometimes-difficult task of
+.Ix 0 ref debugging
+making sure the darn thing works. Your most helpful tool to make sure
+the makefile is at least syntactically correct is the
+.B \-n
+.Ix 0 ref flags -n
+flag, which allows you to see if PMake will choke on the makefile. The
+second thing the
+.B \-n
+flag lets you do is see what PMake would do without it actually doing
+it, thus you can make sure the right commands would be executed were
+you to give PMake its head.
+.LP
+When you find your makefile isn't behaving as you hoped, the first
+question that comes to mind (after ``What time is it, anyway?'') is
+``Why not?'' In answering this, two flags will serve you well:
+.CW "-d m" '' ``
+.Ix 0 ref flags -d
+and
+.CW "-p 2" .'' ``
+.Ix 0 ref flags -p
+The first causes PMake to tell you as it examines each target in the
+makefile and indicate why it is deciding whatever it is deciding. You
+can then use the information printed for other targets to see where
+you went wrong. The
+.CW "-p 2" '' ``
+flag makes PMake print out its internal state when it is done,
+allowing you to see that you forgot to make that one chapter depend on
+that file of macros you just got a new version of. The output from
+.CW "-p 2" '' ``
+is intended to resemble closely a real makefile, but with additional
+information provided and with variables expanded in those commands
+PMake actually printed or executed.
+.LP
+Something to be especially careful about is circular dependencies.
+.Ix 0 def dependency circular
+E.g.
+.DS
+a		: b
+b		: c d
+d		: a
+.DE
+In this case, because of how PMake works,
+.CW c
+is the only thing PMake will examine, because
+.CW d
+and
+.CW a
+will effectively fall off the edge of the universe, making it
+impossible to examine
+.CW b
+(or them, for that matter).
+PMake will tell you (if run in its normal mode) all the targets
+involved in any cycle it looked at (i.e. if you have two cycles in the
+graph (naughty, naughty), but only try to make a target in one of
+them, PMake will only tell you about that one. You'll have to try to
+make the other to find the second cycle). When run as Make, it will
+only print the first target in the cycle.
+.xH 2 Invoking PMake
+.LP
+.Ix 0 ref flags
+.Ix 0 ref arguments
+.Ix 0 ref usage
+PMake comes with a wide variety of flags to choose from.
+They may appear in any order, interspersed with command-line variable
+assignments and targets to create.
+The flags are as follows:
+.IP "\fB\-d\fP \fIwhat\fP"
+.Ix 0 def flags -d
+.Ix 0 ref debugging
+This causes PMake to spew out debugging information that
+may prove useful to you. If you can't
+figure out why PMake is doing what it's doing, you might try using
+this flag. The
+.I what
+parameter is a string of single characters that tell PMake what
+aspects you are interested in. Most of what I describe will make
+little sense to you, unless you've dealt with Make before. Just
+remember where this table is and come back to it as you read on.
+The characters and the information they produce are as follows:
+.RS
+.IP a
+Archive searching and caching.
+.IP c
+Conditional evaluation.
+.IP d
+The searching and caching of directories.
+.IP j
+Various snippets of information related to the running of the multiple
+shells. Not particularly interesting.
+.IP m
+The making of each target: what target is being examined; when it was
+last modified; whether it is out-of-date; etc.
+.IP p
+Makefile parsing.
+.IP r
+Remote execution.
+.IP s
+The application of suffix-transformation rules. (See chapter 3)
+.IP t
+The maintenance of the list of targets.
+.IP v
+Variable assignment.
+.RE
+.IP "\&"
+Of these all, the
+.CW m
+and
+.CW s
+letters will be most useful to you.
+If the
+.B \-d
+is the final argument or the argument from which it would get these
+key letters (see below for a note about which argument would be used)
+begins with a
+.B \- ,
+all of these debugging flags will be set, resulting in massive amounts
+of output.
+.IP "\fB\-f\fP \fImakefile\fP"
+.Ix 0 def flags -f
+Specify a makefile to read different from the standard makefiles
+.CW Makefile "\&" (
+or
+.CW makefile ).
+.Ix 0 ref makefile default
+.Ix 0 ref makefile other
+If
+.I makefile
+is ``\-'', PMake uses the standard input. This is useful for making
+quick and dirty makefiles.\|.\|.
+.Ix 0 ref makefile "quick and dirty"
+.IP \fB\-h\fP
+.Ix 0 def flags -h
+Prints out a summary of the various flags PMake accepts. It can also
+be used to find out what level of concurrency was compiled into the
+version of PMake you are using (look at
+.B \-J
+and
+.B \-L )
+and various other information on how PMake was configured.
+.Ix 0 ref configuration
+.Ix 0 ref makefile system
+.IP \fB\-i\fP
+.Ix 0 def flags -i
+If you give this flag, PMake will ignore non-zero status returned
+by any of its shells. It's like placing a `\-' before all the commands
+in the makefile.
+.IP \fB\-k\fP
+.Ix 0 def flags -k
+This is similar to
+.B \-i
+in that it allows PMake to continue when it sees an error, but unlike
+.B \-i ,
+where PMake continues blithely as if nothing went wrong,
+.B \-k
+causes it to recognize the error and only continue work on those
+things that don't depend on the target, either directly or indirectly (through
+depending on something that depends on it), whose creation returned the error.
+The `k' is for ``keep going''.\|.\|.
+.Ix 0 ref target
+.IP \fB\-l\fP
+.Ix 0 def flags -l
+PMake has the ability to lock a directory against other
+people executing it in the same directory (by means of a file called
+``LOCK.make'' that it creates and checks for in the directory). This
+is a Good Thing because two people doing the same thing in the same place
+can be disastrous for the final product (too many cooks and all that).
+Whether this locking is the default is up to your system
+administrator. If locking is on,
+.B \-l
+will turn it off, and vice versa. Note that this locking will not
+prevent \fIyou\fP from invoking PMake twice in the same place \*- if
+you own the lock file, PMake will warn you about it but continue to execute.
+.IP \fB\-n\fP
+.Ix 0 def flags -n
+This flag tells PMake not to execute the commands needed to update the
+out-of-date targets in the makefile. Rather, PMake will simply print
+the commands it would have executed and exit. This is particularly
+useful for checking the correctness of a makefile. If PMake doesn't do
+what you expect it to, it's a good chance the makefile is wrong.
+.IP "\fB\-p\fP \fInumber\fP"
+.Ix 0 def flags -p
+.Ix 0 ref debugging
+This causes PMake to print its input in a reasonable form, though
+not necessarily one that would make immediate sense to anyone but me. The
+.I number
+is a bitwise-or of 1 and 2 where 1 means it should print the input
+before doing any processing and 2 says it should print it after
+everything has been re-created. Thus
+.CW "\-p 3"
+would print it twice\*-once before processing and once after (you
+might find the difference between the two interesting). This is mostly
+useful to me, but you may find it informative in some bizarre circumstances.
+.IP \fB\-q\fP
+.Ix 0 def flags -q
+If you give PMake this flag, it will not try to re-create anything. It
+will just see if anything is out-of-date and exit non-zero if so.
+.IP \fB\-r\fP
+.Ix 0 def flags -r
+When PMake starts up, it reads a default makefile that tells it what
+sort of system it's on and gives it some idea of what to do if you
+don't tell it anything. I'll tell you about it in chapter 3. If you
+give this flag, PMake won't read the default makefile.
+.IP \fB\-s\fP
+.Ix 0 def flags -s
+This causes PMake to not print commands before they're executed. It
+is the equivalent of putting an `@' before every command in the
+makefile.
+.IP \fB\-t\fP
+.Ix 0 def flags -t
+Rather than try to re-create a target, PMake will simply ``touch'' it
+so as to make it appear up-to-date. If the target didn't exist before,
+it will when PMake finishes, but if the target did exist, it will
+appear to have been updated.
+.IP \fB\-v\fP
+.Ix 0 def flags -v
+This is a mixed-compatibility flag intended to mimic the System V
+version of Make. It is the same as giving
+.B \-B ,
+and
+.B \-V
+as well as turning off directory locking. Targets can still be created
+in parallel, however. This is the mode PMake will enter if it is
+invoked either as
+.CW smake '' ``
+or
+.CW vmake ''. ``
+.IP \fB\-x\fP
+.Ix 0 def flags -x
+This tells PMake it's ok to export jobs to other machines, if they're
+available. It is used when running in Make mode, as exporting in this
+mode tends to make things run slower than if the commands were just
+executed locally.
+.IP \fB\-B\fP
+.Ix 0 ref compatibility
+.Ix 0 def flags -B
+Forces PMake to be as backwards-compatible with Make as possible while
+still being itself.
+This includes:
+.RS
+.IP \(bu 2
+Executing one shell per shell command
+.IP \(bu 2
+Expanding anything that looks even vaguely like a variable, with the
+empty string replacing any variable PMake doesn't know.
+.IP \(bu 2
+Refusing to allow you to escape a `#' with a backslash.
+.IP \(bu 2
+Permitting undefined variables on dependency lines and conditionals
+(see below). Normally this causes PMake to abort.
+.RE
+.IP \fB\-C\fP
+.Ix 0 def flags -C
+This nullifies any and all compatibility mode flags you may have given
+or implied up to the time the
+.B \-C
+is encountered. It is useful mostly in a makefile that you wrote for PMake
+to avoid bad things happening when someone runs PMake as
+.CW make '' ``
+or has things set in the environment that tell it to be compatible.
+.B \-C
+is
+.I not
+placed in the
+.CW PMAKE
+environment variable or the
+.CW .MAKEFLAGS
+or
+.CW MFLAGS
+global variables.
+.Ix 0 ref variable environment PMAKE
+.Ix 0 ref variable global .MAKEFLAGS
+.Ix 0 ref variable global MFLAGS
+.Ix 0 ref .MAKEFLAGS variable
+.Ix 0 ref MFLAGS
+.IP "\fB\-D\fP \fIvariable\fP"
+.Ix 0 def flags -D
+Allows you to define a variable to have 
+.CW 1 '' ``
+as its value.  The variable is a global variable, not a command-line
+variable. This is useful mostly for people who are used to the C
+compiler arguments and those using conditionals, which I'll get into
+in section 4.3
+.Rm 1 4.3
+.IP "\fB\-I\fP \fIdirectory\fP"
+.Ix 0 def flags -I
+Tells PMake another place to search for included makefiles. Yet
+another thing to be explained in chapter 3 (section 3.2, to be
+precise).
+.Rm 2 3.2
+.IP "\fB\-J\fP \fInumber\fP"
+.Ix 0 def flags -J
+Gives the absolute maximum number of targets to create at once on both
+local and remote machines.
+.IP "\fB\-L\fP \fInumber\fP"
+.Ix 0 def flags -L
+This specifies the maximum number of targets to create on the local
+machine at once. This may be 0, though you should be wary of doing
+this, as PMake may hang until a remote machine becomes available, if
+one is not available when it is started.
+.IP \fB\-M\fP
+.Ix 0 ref compatibility
+.Ix 0 def flags -M
+This is the flag that provides absolute, complete, full compatibility
+with Make. It still allows you to use all but a few of the features of
+PMake, but it is non-parallel. This is the mode PMake enters if you
+call it
+.CW make .'' ``
+.IP \fB\-P\fP
+.Ix 0 def flags -P
+.Ix 0 ref "output control"
+When creating targets in parallel, several shells are executing at
+once, each wanting to write its own two cent's-worth to the screen.
+This output must be captured by PMake in some way in order to prevent
+the screen from being filled with garbage even more indecipherable
+than you usually see. PMake has two ways of doing this, one of which
+provides for much cleaner output and a clear separation between the
+output of different jobs, the other of which provides a more immediate
+response so one can tell what is really happpening. The former is done
+by notifying you when the creation of a target starts, capturing the
+output and transferring it to the screen all at once when the job
+finishes. The latter is done by catching the output of the shell (and
+its children) and buffering it until an entire line is received, then
+printing that line preceded by an indication of which job produced
+the output. Since I prefer this second method, it is the one used by
+default. The first method will be used if you give the
+.B \-P
+flag to PMake.
+.IP \fB\-V\fP
+.Ix 0 def flags -V
+As mentioned before, the
+.B \-V
+flag tells PMake to use Make's style of expanding variables,
+substituting the empty string for any variable it doesn't know.
+.IP \fB\-W\fP
+.Ix 0 def flags -W
+There are several times when PMake will print a message at you that is
+only a warning, i.e. it can continue to work in spite of your having
+done something silly (such as forgotten a leading tab for a shell
+command). Sometimes you are well aware of silly things you have done
+and would like PMake to stop bothering you. This flag tells it to shut
+up about anything non-fatal.
+.IP \fB\-X\fP
+.Ix 0 def flags -X
+This flag causes PMake to not attempt to export any jobs to another
+machine.
+.LP
+Several flags may follow a single `\-'. Those flags that require
+arguments take them from successive parameters. E.g.
+.DS
+pmake -fDnI server.mk DEBUG /chip2/X/server/include
+.DE
+will cause PMake to read
+.CW server.mk
+as the input makefile, define the variable
+.CW DEBUG
+as a global variable and look for included makefiles in the directory
+.CW /chip2/X/server/include .
+.xH 2 Summary
+.LP
+A makefile is made of four types of lines:
+.RS
+.IP \(bu 2
+Dependency lines
+.IP \(bu 2
+Creation commands
+.IP \(bu 2
+Variable assignments
+.IP \(bu 2
+Comments, include statements and conditional directives
+.RE
+.LP
+A dependency line is a list of one or more targets, an operator
+.CW : ', (`
+.CW :: ', `
+or
+.CW ! '), `
+and a list of zero or more sources. Sources may contain wildcards and
+certain local variables.
+.LP
+A creation command is a regular shell command preceded by a tab. In
+addition, if the first two characters after the tab (and other
+whitespace) are a combination of
+.CW @ ' `
+or
+.CW - ', `
+PMake will cause the command to not be printed (if the character is
+.CW @ ') `
+or errors from it to be ignored (if
+.CW - '). `
+A blank line, dependency line or variable assignment terminates a
+creation script. There may be only one creation script for each target
+with a
+.CW : ' `
+or
+.CW ! ' `
+operator.
+.LP
+Variables are places to store text. They may be unconditionally
+assigned-to using the
+.CW = ' `
+.Ix 0 ref =
+.Ix 0 ref variable assignment
+operator, appended-to using the
+.CW += ' `
+.Ix 0 ref +=
+.Ix 0 ref variable assignment appended
+operator, conditionally (if the variable is undefined) assigned-to
+with the
+.CW ?= ' `
+.Ix 0 ref ?=
+.Ix 0 ref variable assignment conditional
+operator, and assigned-to with variable expansion with the
+.CW := ' `
+.Ix 0 ref :=
+.Ix 0 ref variable assignment expanded
+operator. The output of a shell command may be assigned to a variable
+using the
+.CW != ' `
+.Ix 0 ref !=
+.Ix 0 ref variable assignment shell-output
+operator.  Variables may be expanded (their value inserted) by enclosing
+their name in parentheses or curly braces, prceeded by a dollar sign.
+A dollar sign may be escaped with another dollar sign. Variables are
+not expanded if PMake doesn't know about them. There are seven local
+variables:
+.CW .TARGET ,
+.CW .ALLSRC ,
+.CW .OODATE ,
+.CW .PREFIX ,
+.CW .IMPSRC ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER .
+Four of them
+.CW .TARGET , (
+.CW .PREFIX ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER )
+may be used to specify ``dynamic sources.''
+.Ix 0 ref "dynamic source"
+.Ix 0 ref source dynamic
+Variables are good. Know them. Love them. Live them.
+.LP
+Debugging of makefiles is best accomplished using the
+.B \-n ,
+.B "\-d m" ,
+and
+.B "\-p 2"
+flags.
+.xH 2 Exercises
+.ce
+\s+4\fBTBA\fP\s0
+.xH 1 Short-cuts and Other Nice Things
+.LP
+Based on what I've told you so far, you may have gotten the impression
+that PMake is just a way of storing away commands and making sure you
+don't forget to compile something. Good. That's just what it is.
+However, the ways I've described have been inelegant, at best, and
+painful, at worst.
+This chapter contains things that make the
+writing of makefiles easier and the makefiles themselves shorter and
+easier to modify (and, occasionally, simpler). In this chapter, I
+assume you are somewhat more
+familiar with Sprite (or UNIX, if that's what you're using) than I did
+in chapter 2, just so you're on your toes.
+So without further ado...
+.xH 2 Transformation Rules
+.LP
+As you know, a file's name consists of two parts: a base name, which
+gives some hint as to the contents of the file, and a suffix, which
+usually indicates the format of the file.
+Over the years, as
+.UX
+has developed,
+naming conventions, with regard to suffixes, have also developed that have
+become almost as incontrovertible as Law. E.g. a file ending in
+.CW .c
+is assumed to contain C source code; one with a
+.CW .o
+suffix is assumed to be a compiled, relocatable object file that may
+be linked into any program; a file with a
+.CW .ms
+suffix is usually a text file to be processed by Troff with the \-ms
+macro package, and so on.
+One of the best aspects of both Make and PMake comes from their
+understanding of how the suffix of a file pertains to its contents and
+their ability to do things with a file based soley on its suffix. This
+ability comes from something known as a transformation rule. A
+transformation rule specifies how to change a file with one suffix
+into a file with another suffix.
+.LP
+A transformation rule looks much like a dependency line, except the
+target is made of two known suffixes stuck together. Suffixes are made
+known to PMake by placing them as sources on a dependency line whose
+target is the special target
+.CW .SUFFIXES .
+E.g.
+.DS
+\&.SUFFIXES       : .o .c
+\&.c.o            :
+        $(CC) $(CFLAGS) -c $(.IMPSRC)
+.DE
+The creation script attached to the target is used to transform a file with
+the first suffix (in this case,
+.CW .c )
+into a file with the second suffix (here,
+.CW .o ).
+In addition, the target inherits whatever attributes have been applied
+to the transformation rule.
+The simple rule given above says that to transform a C source file
+into an object file, you compile it using
+.CW cc
+with the
+.CW \-c
+flag.
+This rule is taken straight from the system makefile. Many
+transformation rules (and suffixes) are defined there, and I refer you
+to it for more examples (type
+.CW "pmake -h" '' ``
+to find out where it is).
+.LP
+There are several things to note about the transformation rule given
+above:
+.RS
+.IP 1)
+The
+.CW .IMPSRC 
+variable.
+.Ix 0 def variable local .IMPSRC
+.Ix 0 def .IMPSRC
+This variable is set to the ``implied source'' (the file from which
+the target is being created; the one with the first suffix), which, in this
+case, is the .c file.
+.IP 2)
+The
+.CW CFLAGS
+variable. Almost all of the transformation rules in the system
+makefile are set up using variables that you can alter in your
+makefile to tailor the rule to your needs. In this case, if you want
+all your C files to be compiled with the
+.B \-g
+flag, to provide information for
+.CW dbx ,
+you would set the
+.CW CFLAGS
+variable to contain
+.CW -g
+.CW "CFLAGS = -g" '') (``
+and PMake would take care of the rest.
+.RE
+.LP
+To give you a quick example, the makefile in 2.3.4 
+.Rm 3 2.3.4
+could be changed to this:
+.DS
+OBJS            = a.o b.o c.o
+program         : $(OBJS)
+        $(CC) -o $(.TARGET) $(.ALLSRC)
+$(OBJS)         : defs.h
+.DE
+The transformation rule I gave above takes the place of the 6 lines\**
+.FS
+This is also somewhat cleaner, I think, than the dynamic source
+solution presented in 2.6
+.FE
+.Rm 4 2.6
+.DS
+a.o             : a.c
+        cc -c a.c
+b.o             : b.c
+        cc -c b.c
+c.o             : c.c
+        cc -c c.c
+.DE
+.LP
+Now you may be wondering about the dependency between the
+.CW .o
+and
+.CW .c
+files \*- it's not mentioned anywhere in the new makefile. This is
+because it isn't needed: one of the effects of applying a
+transformation rule is the target comes to depend on the implied
+source. That's why it's called the implied
+.I source .
+.LP
+For a more detailed example. Say you have a makefile like this:
+.DS
+a.out           : a.o b.o
+        $(CC) $(.ALLSRC)
+.DE
+and a directory set up like this:
+.DS
+total 4
+-rw-rw-r--  1 deboor         34 Sep  7 00:43 Makefile
+-rw-rw-r--  1 deboor        119 Oct  3 19:39 a.c
+-rw-rw-r--  1 deboor        201 Sep  7 00:43 a.o
+-rw-rw-r--  1 deboor         69 Sep  7 00:43 b.c
+.DE
+While just typing
+.CW pmake '' ``
+will do the right thing, it's much more informative to type
+.CW "pmake -d s" ''. ``
+This will show you what PMake is up to as it processes the files. In
+this case, PMake prints the following:
+.DS
+Suff_FindDeps (a.out)
+	using existing source a.o
+	applying .o -> .out to "a.o"
+Suff_FindDeps (a.o)
+	trying a.c...got it
+	applying .c -> .o to "a.c"
+Suff_FindDeps (b.o)
+	trying b.c...got it
+	applying .c -> .o to "b.c"
+Suff_FindDeps (a.c)
+	trying a.y...not there
+	trying a.l...not there
+	trying a.c,v...not there
+	trying a.y,v...not there
+	trying a.l,v...not there
+Suff_FindDeps (b.c)
+	trying b.y...not there
+	trying b.l...not there
+	trying b.c,v...not there
+	trying b.y,v...not there
+	trying b.l,v...not there
+--- a.o ---
+cc  -c a.c
+--- b.o ---
+cc  -c b.c
+--- a.out ---
+cc a.o b.o
+.DE
+.LP
+.CW Suff_FindDeps
+is the name of a function in PMake that is called to check for implied
+sources for a target using transformation rules.
+The transformations it tries are, naturally
+enough, limited to the ones that have been defined (a transformation
+may be defined multiple times, by the way, but only the most recent
+one will be used). You will notice, however, that there is a definite
+order to the suffixes that are tried. This order is set by the
+relative positions of the suffixes on the
+.CW .SUFFIXES
+line \*- the earlier a suffix appears, the earlier it is checked as
+the source of a transformation. Once a suffix has been defined, the
+only way to change its position in the pecking order is to remove all
+the suffixes (by having a
+.CW .SUFFIXES
+dependency line with no sources) and redefine them in the order you
+want. (Previously-defined transformation rules will be automatically
+redefined as the suffixes they involve are re-entered.)
+.LP
+Another way to affect the search order is to make the dependency
+explicit. In the above example,
+.CW a.out
+depends on
+.CW a.o
+and
+.CW b.o .
+Since a transformation exists from
+.CW .o
+to
+.CW .out ,
+PMake uses that, as indicated by the
+.CW "using existing source a.o" '' ``
+message.
+.LP
+The search for a transformation starts from the suffix of the target
+and continues through all the defined transformations, in the order
+dictated by the suffix ranking, until an existing file with the same
+base (the target name minus the suffix and any leading directories) is
+found. At that point, one or more transformation rules will have been
+found to change the one existing file into the target.
+.LP
+For example, ignoring what's in the system makefile for now, say you
+have a makefile like this:
+.DS
+\&.SUFFIXES       : .out .o .c .y .l
+\&.l.c            :
+        lex $(.IMPSRC)
+        mv lex.yy.c $(.TARGET)
+\&.y.c            :
+        yacc $(.IMPSRC)
+        mv y.tab.c $(.TARGET)
+\&.c.o            :
+        cc -c $(.IMPSRC)
+\&.o.out          :
+        cc -o $(.TARGET) $(.IMPSRC)
+.DE
+and the single file
+.CW jive.l .
+If you were to type
+.CW "pmake -rd ms jive.out" ,'' ``
+you would get the following output for
+.CW jive.out :
+.DS
+Suff_FindDeps (jive.out)
+	trying jive.o...not there
+	trying jive.c...not there
+	trying jive.y...not there
+	trying jive.l...got it
+	applying .l -> .c to "jive.l"
+	applying .c -> .o to "jive.c"
+	applying .o -> .out to "jive.o"
+.DE
+and this is why: PMake starts with the target
+.CW jive.out ,
+figures out its suffix
+.CW .out ) (
+and looks for things it can transform to a
+.CW .out
+file. In this case, it only finds
+.CW .o ,
+so it looks for the file
+.CW jive.o .
+It fails to find it, so it looks for transformations into a
+.CW .o
+file. Again it has only one choice:
+.CW .c .
+So it looks for
+.CW jive.c
+and, as you know, fails to find it. At this point it has two choices:
+it can create the
+.CW .c
+file from either a
+.CW .y
+file or a
+.CW .l
+file. Since
+.CW .y
+came first on the
+.CW .SUFFIXES
+line, it checks for
+.CW jive.y
+first, but can't find it, so it looks for
+.CW jive.l
+and, lo and behold, there it is.
+At this point, it has defined a transformation path as follows:
+.CW .l
+\(->
+.CW .c
+\(->
+.CW .o
+\(->
+.CW .out
+and applies the transformation rules accordingly. For completeness,
+and to give you a better idea of what PMake actually did with this
+three-step transformation, this is what PMake printed for the rest of
+the process:
+.DS
+Suff_FindDeps (jive.o)
+	using existing source jive.c
+	applying .c -> .o to "jive.c"
+Suff_FindDeps (jive.c)
+	using existing source jive.l
+	applying .l -> .c to "jive.l"
+Suff_FindDeps (jive.l)
+Examining jive.l...modified 17:16:01 Oct 4, 1987...up-to-date
+Examining jive.c...non-existent...out-of-date
+--- jive.c ---
+lex jive.l
+\&.\|.\|. meaningless lex output deleted .\|.\|.
+mv lex.yy.c jive.c
+Examining jive.o...non-existent...out-of-date
+--- jive.o ---
+cc -c jive.c
+Examining jive.out...non-existent...out-of-date
+--- jive.out ---
+cc -o jive.out jive.o
+.DE
+.LP
+One final question remains: what does PMake do with targets that have
+no known suffix? PMake simply pretends it actually has a known suffix
+and searches for transformations accordingly.
+The suffix it chooses is the source for the
+.CW .NULL
+.Ix 0 ref .NULL
+target mentioned later. In the system makefile, 
+.CW .out
+is chosen as the ``null suffix''
+.Ix 0 def suffix null
+.Ix 0 def "null suffix"
+because most people use PMake to create programs. You are, however,
+free and welcome to change it to a suffix of your own choosing.
+The null suffix is ignored, however, when PMake is in compatibility
+mode (see chapter 4).
+.xH 2 Including Other Makefiles
+.Ix 0 def makefile inclusion
+.Rd 2
+.LP
+Just as for programs, it is often useful to extract certain parts of a
+makefile into another file and just include it in other makefiles
+somehow. Many compilers allow you say something like
+.DS
+#include "defs.h"
+.DE
+to include the contents of
+.CW defs.h
+in the source file. PMake allows you to do the same thing for
+makefiles, with the added ability to use variables in the filenames.
+An include directive in a makefile looks either like this:
+.DS
+#include <file>
+.DE
+or this
+.DS
+#include "file"
+.DE
+The difference between the two is where PMake searches for the file:
+the first way, PMake will look for
+the file only in the system makefile directory (to find out what that
+directory is, give PMake the
+.B \-h
+flag).
+.Ix 0 ref flags -h
+For files in double-quotes, the search is more complex:
+.RS
+.IP 1)
+The directory of the makefile that's including the file.
+.IP 2)
+The current directory (the one in which you invoked PMake).
+.IP 3)
+The directories given by you using
+.B \-I
+flags, in the order in which you gave them.
+.IP 4)
+Directories given by
+.CW .PATH
+dependency lines (see chapter 4).
+.IP 5)
+The system makefile directory.
+.RE
+.LP
+in that order.
+.LP
+You are free to use PMake variables in the filename\*-PMake will
+expand them before searching for the file. You must specify the
+searching method with either angle brackets or double-quotes
+.I outside
+of a variable expansion. I.e. the following
+.DS
+SYSTEM	= <command.mk>
+
+#include $(SYSTEM)
+.DE
+won't work.
+.xH 2 Saving Commands
+.LP
+.Ix 0 def ...
+There may come a time when you will want to save certain commands to
+be executed when everything else is done. For instance: you're
+making several different libraries at one time and you want to create the
+members in parallel. Problem is,
+.CW ranlib
+is another one of those programs that can't be run more than once in
+the same directory at the same time (each one creates a file called
+.CW __.SYMDEF
+into which it stuffs information for the linker to use. Two of them
+running at once will overwrite each other's file and the result will
+be garbage for both parties). You might want a way to save the ranlib
+commands til the end so they can be run one after the other, thus
+keeping them from trashing each other's file. PMake allows you to do
+this by inserting an ellipsis (``.\|.\|.'') as a command between
+commands to be run at once and those to be run later.
+.LP
+So for the
+.CW ranlib
+case above, you might do this:
+.Rd 5
+.DS
+lib1.a          : $(LIB1OBJS)
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+
+lib2.a          : $(LIB2OBJS)
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+This would save both
+.DS
+ranlib $(.TARGET)
+.DE
+commands until the end, when they would run one after the other
+(using the correct value for the
+.CW .TARGET
+variable, of course).
+.LP
+Commands saved in this manner are only executed if PMake manages to
+re-create everything without an error.
+.xH 2 Target Attributes
+.LP
+PMake allows you to give attributes to targets by means of special
+sources. Like everything else PMake uses, these sources begin with a
+period and are made up of all upper-case letters. There are various
+reasons for using them, and I will try to give examples for most of
+them. Others you'll have to find uses for yourself. Think of it as ``an
+exercise for the reader.'' By placing one (or more) of these as a source on a
+dependency line, you are ``marking the target(s) with that
+attribute.'' That's just the way I phrase it, so you know.
+.LP
+Any attributes given as sources for a transformation rule are applied
+to the target of the transformation rule when the rule is applied.
+.Ix 0 def attributes
+.Ix 0 ref source
+.Ix 0 ref target
+.nr pw 12
+.IP .DONTCARE \n(pw
+.Ix 0 def attributes .DONTCARE
+.Ix 0 def .DONTCARE
+If a target is marked with this attribute and PMake can't figure out
+how to create it, it will ignore this fact and assume the file isn't
+really needed or actually exists and PMake just can't find it. This may prove
+wrong, but the error will be noted later on, not when PMake tries to create
+the target so marked. This attribute also prevents PMake from
+attempting to touch the target if it is given the
+.B \-t
+flag.
+.Ix 0 ref flags -t
+.IP .EXEC \n(pw
+.Ix 0 def attributes .EXEC
+.Ix 0 def .EXEC
+This attribute causes its shell script to be executed while having no
+effect on targets that depend on it. This makes the target into a sort
+of subroutine.  An example. Say you have some LISP files that need to
+be compiled and loaded into a LISP process. To do this, you echo LISP
+commands into a file and execute a LISP with this file as its input
+when everything's done. Say also that you have to load other files
+from another system before you can compile your files and further,
+that you don't want to go through the loading and dumping unless one
+of
+.I your
+files has changed. Your makefile might look a little bit
+like this (remember, this is an educational example, and don't worry
+about the
+.CW COMPILE
+rule, all will soon become clear, grasshopper):
+.DS
+system          : init a.fasl b.fasl c.fasl
+        for i in $(.ALLSRC);
+        do
+                echo -n '(load "' >> input
+                echo -n ${i} >> input
+                echo '")' >> input
+        done
+        echo '(dump "$(.TARGET)")' >> input
+        lisp < input
+
+a.fasl          : a.l init COMPILE
+b.fasl          : b.l init COMPILE
+c.fasl          : c.l init COMPILE
+COMPILE         : .USE
+        echo '(compile "$(.ALLSRC)")' >> input
+init            : .EXEC
+        echo '(load-system)' > input
+.DE
+.Ix 0 ref .USE
+.Ix 0 ref attributes .USE
+.Ix 0 ref variable local .ALLSRC
+.IP "\&"
+.CW .EXEC
+sources, don't appear in the local variables of targets that depend on
+them (nor are they touched if PMake is given the
+.B \-t
+flag).
+.Ix 0 ref flags -t
+Note that all the rules, not just that for
+.CW system ,
+include
+.CW init
+as a source. This is because none of the other targets can be made
+until
+.CW init
+has been made, thus they depend on it.
+.IP .EXPORT \n(pw
+.Ix 0 def attributes .EXPORT
+.Ix 0 def .EXPORT
+This is used to mark those targets whose creation should be sent to
+another machine if at all possible. This may be used by some
+exportation schemes if the exportation is expensive. You should ask
+your system administrator if it is necessary.
+.IP .EXPORTSAME \n(pw
+.Ix 0 def attributes .EXPORTSAME
+.Ix 0 def .EXPORTSAME
+Tells the export system that the job should be exported to a machine
+of the same architecture as the current one. Certain operations (e.g.
+running text through
+.CW nroff )
+can be performed the same on any architecture (CPU and
+operating system type), while others (e.g. compiling a program with
+.CW cc )
+must be performed on a machine with the same architecture. Not all
+export systems will support this attribute.
+.IP .IGNORE \n(pw
+.Ix 0 def attributes .IGNORE
+.Ix 0 def .IGNORE attribute
+Giving a target the
+.CW .IGNORE
+attribute causes PMake to ignore errors from any of the target's commands, as
+if they all had `\-' before them.
+.IP .INVISIBLE \n(pw
+.Ix 0 def attributes .INVISIBLE
+.Ix 0 def .INVISIBLE
+This allows you to specify one target as a source for another without
+the one affecting the other's local variables. Useful if, say, you
+have a makefile that creates two programs, one of which is used to
+create the other, so it must exist before the other is created. You
+could say
+.DS
+prog1           : $(PROG1OBJS) prog2 MAKEINSTALL
+prog2           : $(PROG2OBJS) .INVISIBLE MAKEINSTALL
+.DE
+where
+.CW MAKEINSTALL
+is some complex .USE rule (see below) that depends on the
+.Ix 0 ref .USE
+.CW .ALLSRC
+variable containing the right things. Without the
+.CW .INVISIBLE
+attribute for
+.CW prog2 ,
+the
+.CW MAKEINSTALL
+rule couldn't be applied. This is not as useful as it should be, and
+the semantics may change (or the whole thing go away) in the
+not-too-distant future.
+.IP .JOIN \n(pw
+.Ix 0 def attributes .JOIN
+.Ix 0 def .JOIN
+This is another way to avoid performing some operations in parallel
+while permitting everything else to be done so. Specifically it
+forces the target's shell script to be executed only if one or more of the
+sources was out-of-date. In addition, the target's name,
+in both its
+.CW .TARGET
+variable and all the local variables of any target that depends on it,
+is replaced by the value of its
+.CW .ALLSRC
+variable.
+As an example, suppose you have a program that has four libraries that
+compile in the same directory along with, and at the same time as, the
+program. You again have the problem with
+.CW ranlib
+that I mentioned earlier, only this time it's more severe: you
+can't just put the ranlib off to the end since the program
+will need those libraries before it can be re-created. You can do
+something like this:
+.DS
+program         : $(OBJS) libraries
+        cc -o $(.TARGET) $(.ALLSRC)
+
+libraries       : lib1.a lib2.a lib3.a lib4.a .JOIN
+        ranlib $(.OODATE)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+.Ix 0 ref variable local .OODATE
+.Ix 0 ref .TARGET
+.Ix 0 ref .ALLSRC
+.Ix 0 ref .OODATE
+In this case, PMake will re-create the
+.CW $(OBJS)
+as necessary, along with
+.CW lib1.a ,
+.CW lib2.a ,
+.CW lib3.a
+and
+.CW lib4.a .
+It will then execute
+.CW ranlib
+on any library that was changed and set
+.CW program 's
+.CW .ALLSRC
+variable to contain what's in
+.CW $(OBJS)
+followed by
+.CW "lib1.a lib2.a lib3.a lib4.a" .'' ``
+In case you're wondering, it's called
+.CW .JOIN
+because it joins together different threads of the ``input graph'' at
+the target marked with the attribute.
+Another aspect of the .JOIN attribute is it keeps the target from
+being created if the
+.B \-t
+flag was given.
+.Ix 0 ref flags -t
+.IP .MAKE \n(pw
+.Ix 0 def attributes .MAKE
+.Ix 0 def .MAKE
+The
+.CW .MAKE
+attribute marks its target as being a recursive invocation of PMake.
+This forces PMake to execute the script associated with the target (if
+it's out-of-date) even if you gave the
+.B \-n
+or
+.B \-t
+flag. By doing this, you can start at the top of a system and type
+.DS
+pmake -n
+.DE
+and have it descend the directory tree (if your makefiles are set up
+correctly), printing what it would have executed if you hadn't
+included the
+.B \-n
+flag.
+.IP .NOEXPORT \n(pw
+.Ix 0 def attributes .NOEXPORT
+.Ix 0 def .NOEXPORT attribute
+If possible, PMake will attempt to export the creation of all targets to
+another machine (this depends on how PMake was configured). Sometimes,
+the creation is so simple, it is pointless to send it to another
+machine. If you give the target the
+.CW .NOEXPORT
+attribute, it will be run locally, even if you've given PMake the
+.B "\-L 0"
+flag.
+.IP .NOTMAIN \n(pw
+.Ix 0 def attributes .NOTMAIN
+.Ix 0 def .NOTMAIN
+Normally, if you do not specify a target to make in any other way,
+PMake will take the first target on the first dependency line of a
+makefile as the target to create. That target is known as the ``Main
+Target'' and is labeled as such if you print the dependencies out
+using the
+.B \-p
+flag.
+.Ix 0 ref flags -p
+Giving a target this attribute tells PMake that the target is
+definitely
+.I not
+the Main Target.
+This allows you to place targets in an included makefile and
+have PMake create something else by default.
+.IP .PRECIOUS \n(pw
+.Ix 0 def attributes .PRECIOUS
+.Ix 0 def .PRECIOUS attribute
+When PMake is interrupted (you type control-C at the keyboard), it
+will attempt to clean up after itself by removing any half-made
+targets. If a target has the
+.CW .PRECIOUS
+attribute, however, PMake will leave it alone. An additional side
+effect of the `::' operator is to mark the targets as
+.CW .PRECIOUS .
+.Ix 0 ref operator double-colon
+.Ix 0 ref ::
+.IP .SILENT \n(pw
+.Ix 0 def attributes .SILENT
+.Ix 0 def .SILENT attribute
+Marking a target with this attribute keeps its commands from being
+printed when they're executed, just as if they had an `@' in front of them.
+.IP .USE \n(pw
+.Ix 0 def attributes .USE
+.Ix 0 def .USE
+By giving a target this attribute, you turn it into PMake's equivalent
+of a macro. When the target is used as a source for another target,
+the other target acquires the commands, sources and attributes (except
+.CW .USE )
+of the source.
+If the target already has commands, the
+.CW .USE
+target's commands are added to the end. If more than one .USE-marked
+source is given to a target, the rules are applied sequentially.
+.IP "\&" \n(pw
+The typical .USE rule (as I call them) will use the sources of the
+target to which it is applied (as stored in the
+.CW .ALLSRC
+variable for the target) as its ``arguments,'' if you will.
+For example, you probably noticed that the commands for creating
+.CW lib1.a
+and
+.CW lib2.a
+in the example in section 3.3
+.Rm 5 3.3
+were exactly the same. You can use the
+.CW .USE
+attribute to eliminate the repetition, like so:
+.DS
+lib1.a          : $(LIB1OBJS) MAKELIB
+lib2.a          : $(LIB2OBJS) MAKELIB
+
+MAKELIB         : .USE
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+.IP "\&" \n(pw
+Several system makefiles (not to be confused with The System Makefile)
+make use of these  .USE rules to make your
+life easier (they're in the default, system makefile directory...take a look).
+Note that the .USE rule source itself
+.CW MAKELIB ) (
+does not appear in any of the targets's local variables.
+There is no limit to the number of times I could use the
+.CW MAKELIB
+rule. If there were more libraries, I could continue with
+.CW "lib3.a : $(LIB3OBJS) MAKELIB" '' ``
+and so on and so forth.
+.xH 2 Special Targets
+.LP
+As there were in Make, so there are certain targets that have special
+meaning to PMake. When you use one on a dependency line, it is the
+only target that may appear on the left-hand-side of the operator.
+.Ix 0 ref target
+.Ix 0 ref operator
+As for the attributes and variables, all the special targets
+begin with a period and consist of upper-case letters only.
+I won't describe them all in detail because some of them are rather
+complex and I'll describe them in more detail than you'll want in
+chapter 4.
+The targets are as follows:
+.nr pw 10
+.IP .BEGIN \n(pw
+.Ix 0 def .BEGIN
+Any commands attached to this target are executed before anything else
+is done. You can use it for any initialization that needs doing.
+.IP .DEFAULT \n(pw
+.Ix 0 def .DEFAULT
+This is sort of a .USE rule for any target (that was used only as a
+source) that PMake can't figure out any other way to create. It's only
+``sort of'' a .USE rule because only the shell script attached to the
+.CW .DEFAULT
+target is used. The
+.CW .IMPSRC
+variable of a target that inherits
+.CW .DEFAULT 's
+commands is set to the target's own name.
+.Ix 0 ref .IMPSRC
+.Ix 0 ref variable local .IMPSRC
+.IP .END \n(pw
+.Ix 0 def .END
+This serves a function similar to
+.CW .BEGIN ,
+in that commands attached to it are executed once everything has been
+re-created (so long as no errors occurred). It also serves the extra
+function of being a place on which PMake can hang commands you put off
+to the end. Thus the script for this target will be executed before
+any of the commands you save with the ``.\|.\|.''.
+.Ix 0 ref ...
+.IP .EXPORT \n(pw
+The sources for this target are passed to the exportation system compiled
+into PMake. Some systems will use these sources to configure
+themselves. You should ask your system administrator about this.
+.IP .IGNORE \n(pw
+.Ix 0 def .IGNORE target
+.Ix 0 ref .IGNORE attribute
+.Ix 0 ref attributes .IGNORE
+This target marks each of its sources with the
+.CW .IGNORE
+attribute. If you don't give it any sources, then it is like
+giving the
+.B \-i
+flag when you invoke PMake \*- errors are ignored for all commands.
+.Ix 0 ref flags -i
+.IP .INCLUDES \n(pw
+.Ix 0 def .INCLUDES target
+.Ix 0 def variable global .INCLUDES
+.Ix 0 def .INCLUDES variable
+The sources for this target are taken to be suffixes that indicate a
+file that can be included in a program source file.
+The suffix must have already been declared with
+.CW .SUFFIXES
+(see below).
+Any suffix so marked will have the directories on its search path
+(see
+.CW .PATH ,
+below) placed in the
+.CW .INCLUDES
+variable, each preceded by a
+.B \-I
+flag. This variable can then be used as an argument for the compiler
+in the normal fashion. The
+.CW .h
+suffix is already marked in this way in the system makefile.
+.Ix 0 ref makefile system
+E.g. if you have
+.DS
+\&.SUFFIXES       : .bitmap
+\&.PATH.bitmap    : /usr/local/X/lib/bitmaps
+\&.INCLUDES       : .bitmap
+.DE
+PMake will place
+.CW "-I/usr/local/X/lib/bitmaps" '' ``
+in the
+.CW .INCLUDES
+variable and you can then say
+.DS
+cc $(.INCLUDES) -c xprogram.c
+.DE
+(Note: the
+.CW .INCLUDES
+variable is not actually filled in until the entire makefile has been read.)
+.IP .INTERRUPT \n(pw
+.Ix 0 def .INTERRUPT
+When PMake is interrupted,
+it will execute the commands in the script for this target, if it
+exists.
+.IP .LIBS \n(pw
+.Ix 0 def .LIBS target
+.Ix 0 def .LIBS variable
+.Ix 0 def variable global .LIBS
+This does for libraries what
+.CW .INCLUDES
+does for include files, except the flag used is
+.B \-L ,
+as required by those linkers that allow you to tell them where to find
+libraries. The variable used is
+.CW .LIBS .
+Be forewarned that PMake may not have been compiled to do this if the
+linker on your system doesn't accept the
+.B \-L
+flag, though the
+.CW .LIBS
+variable will always be defined once the makefile has been read.
+.IP .MAIN \n(pw
+.Ix 0 def .MAIN
+If you didn't give a target (or targets) to create when you invoked
+PMake, it will take the sources of this target as the targets to
+create.
+.IP .MAKEFLAGS \n(pw
+.Ix 0 def .MAKEFLAGS target
+This target provides a way for you to always specify flags for PMake
+when the makefile is used. The flags are just as they would be typed
+to the shell (except you can't use shell variables unless they're in
+the environment),
+though the
+.B \-f
+and
+.B \-r
+flags have no effect.
+.IP .NULL \n(pw
+.Ix 0 def .NULL
+.Ix 0 ref suffix null
+.Ix 0 ref "null suffix"
+This allows you to specify what suffix PMake should pretend a file has
+if, in fact, it has no known suffix. Only one suffix may be so
+designated. The last source on the dependency line is the suffix that
+is used (you should, however, only give one suffix.\|.\|.).
+.IP .PATH \n(pw
+.Ix 0 def .PATH
+If you give sources for this target, PMake will take them as
+directories in which to search for files it cannot find in the current
+directory. If you give no sources, it will clear out any directories
+added to the search path before. Since the effects of this all get
+very complex, I'll leave it til chapter four to give you a complete
+explanation.
+.IP .PATH\fIsuffix\fP \n(pw
+.Ix 0 ref .PATH
+This does a similar thing to
+.CW .PATH ,
+but it does it only for files with the given suffix. The suffix must
+have been defined already. Look at
+.B "Search Paths"
+(section 4.1)
+.Rm 6 4.1
+for more information.
+.IP .PRECIOUS \n(pw
+.Ix 0 def .PRECIOUS target
+.Ix 0 ref .PRECIOUS attribute
+.Ix 0 ref attributes .PRECIOUS
+Similar to
+.CW .IGNORE ,
+this gives the
+.CW .PRECIOUS
+attribute to each source on the dependency line, unless there are no
+sources, in which case the
+.CW .PRECIOUS
+attribute is given to every target in the file.
+.IP .RECURSIVE \n(pw
+.Ix 0 def .RECURSIVE
+.Ix 0 ref attributes .MAKE
+.Ix 0 ref .MAKE
+This target applies the
+.CW .MAKE
+attribute to all its sources. It does nothing if you don't give it any sources.
+.IP .SHELL \n(pw
+.Ix 0 def .SHELL
+PMake is not constrained to only using the Bourne shell to execute
+the commands you put in the makefile. You can tell it some other shell
+to use with this target. Check out
+.B "A Shell is a Shell is a Shell"
+(section 4.4)
+.Rm 7 4.4
+for more information.
+.IP .SILENT \n(pw
+.Ix 0 def .SILENT target
+.Ix 0 ref .SILENT attribute
+.Ix 0 ref attributes .SILENT
+When you use
+.CW .SILENT
+as a target, it applies the
+.CW .SILENT
+attribute to each of its sources. If there are no sources on the
+dependency line, then it is as if you gave PMake the
+.B \-s
+flag and no commands will be echoed.
+.IP .SUFFIXES \n(pw
+.Ix 0 def .SUFFIXES
+This is used to give new file suffixes for PMake to handle. Each
+source is a suffix PMake should recognize. If you give a
+.CW .SUFFIXES
+dependency line with no sources, PMake will forget about all the
+suffixes it knew (this also nukes the null suffix).
+For those targets that need to have suffixes defined, this is how you do it.
+.LP
+In addition to these targets, a line of the form
+.DS
+\fIattribute\fP : \fIsources\fP
+.DE
+applies the
+.I attribute
+to all the targets listed as
+.I sources .
+.xH 2 Modifying Variable Expansion
+.LP
+.Ix 0 def variable expansion modified
+.Ix 0 ref variable expansion
+.Ix 0 def variable modifiers
+Variables need not always be expanded verbatim. PMake defines several
+modifiers that may be applied to a variable's value before it is
+expanded. You apply a modifier by placing it after the variable name
+with a colon between the two, like so:
+.DS
+${\fIVARIABLE\fP:\fImodifier\fP}
+.DE
+Each modifier is a single character followed by something specific to
+the modifier itself.
+You may apply as many modifiers as you want \*- each one is applied to
+the result of the previous and is separated from the previous by
+another colon.
+.LP
+There are seven ways to modify a variable's expansion, most of which
+come from the C shell variable modification characters:
+.RS
+.IP "M\fIpattern\fP"
+.Ix 0 def :M
+.Ix 0 def modifier match
+This is used to select only those words (a word is a series of
+characters that are neither spaces nor tabs) that match the given
+.I pattern .
+The pattern is a wildcard pattern like that used by the shell, where
+.CW *
+means 0 or more characters of any sort;
+.CW ?
+is any single character;
+.CW [abcd]
+matches any single character that is either `a', `b', `c' or `d'
+(there may be any number of characters between the brackets);
+.CW [0-9]
+matches any single character that is between `0' and `9' (i.e. any
+digit. This form may be freely mixed with the other bracket form), and
+`\\' is used to escape any of the characters `*', `?', `[' or `:',
+leaving them as regular characters to match themselves in a word.
+For example, the system makefile
+.CW <makedepend.mk>
+uses
+.CW "$(CFLAGS:M-[ID]*)" '' ``
+to extract all the
+.CW \-I
+and
+.CW \-D
+flags that would be passed to the C compiler. This allows it to
+properly locate include files and generate the correct dependencies.
+.IP "N\fIpattern\fP"
+.Ix 0 def :N
+.Ix 0 def modifier nomatch
+This is identical to
+.CW :M
+except it substitutes all words that don't match the given pattern.
+.IP "S/\fIsearch-string\fP/\fIreplacement-string\fP/[g]"
+.Ix 0 def :S
+.Ix 0 def modifier substitute
+Causes the first occurrence of
+.I search-string
+in the variable to be replaced by
+.I replacement-string ,
+unless the
+.CW g
+flag is given at the end, in which case all occurences of the string
+are replaced. The substitution is performed on each word in the
+variable in turn. If 
+.I search-string
+begins with a
+.CW ^ ,
+the string must match starting at the beginning of the word. If
+.I search-string
+ends with a
+.CW $ ,
+the string must match to the end of the word (these two may be
+combined to force an exact match). If a backslash preceeds these two
+characters, however, they lose their special meaning. Variable
+expansion also occurs in the normal fashion inside both the
+.I search-string
+and the
+.I replacement-string ,
+.B except
+that a backslash is used to prevent the expansion of a
+.CW $ ,
+not another dollar sign, as is usual.
+Note that
+.I search-string
+is just a string, not a pattern, so none of the usual
+regular-expression/wildcard characters have any special meaning save
+.CW ^
+and
+.CW $ .
+In the replacement string,
+the
+.CW &
+character is replaced by the
+.I search-string
+unless it is preceded by a backslash.
+You are allowed to use any character except
+colon or exclamation point to separate the two strings. This so-called
+delimiter character may be placed in either string by preceeding it
+with a backslash.
+.IP T
+.Ix 0 def :T
+.Ix 0 def modifier tail
+Replaces each word in the variable expansion by its last
+component (its ``tail''). For example, given
+.DS
+OBJS = ../lib/a.o b /usr/lib/libm.a
+TAILS = $(OBJS:T)
+.DE
+the variable
+.CW TAILS
+would expand to
+.CW "a.o b libm.a" .'' ``
+.IP H
+.Ix 0 def :H
+.Ix 0 def modifier head
+This is similar to
+.CW :T ,
+except that every word is replaced by everything but the tail (the
+``head''). Using the same definition of
+.CW OBJS ,
+the string
+.CW "$(OBJS:H)" '' ``
+would expand to
+.CW "../lib /usr/lib" .'' ``
+Note that the final slash on the heads is removed and
+anything without a head is replaced by the empty string.
+.IP E
+.Ix 0 def :E
+.Ix 0 def modifier extension
+.Ix 0 def modifier suffix
+.Ix 0 ref suffix "variable modifier"
+.CW :E
+replaces each word by its suffix (``extension''). So
+.CW "$(OBJS:E)" '' ``
+would give you
+.CW ".o .a" .'' ``
+.IP R
+.Ix 0 def :R
+.Ix 0 def modifier root
+.Ix 0 def modifier base
+This replaces each word by everything but the suffix (the ``root'' of
+the word).
+.CW "$(OBJS:R)" '' ``
+expands to ``
+.CW "../lib/a b /usr/lib/libm" .''
+.RE
+.LP
+In addition, the System V style of substitution is also supported.
+This looks like:
+.DS
+$(\fIVARIABLE\fP:\fIsearch-string\fP=\fIreplacement\fP)
+.DE
+It must be the last modifier in the chain. The search is anchored at
+the end of each word, so only suffixes or whole words may be replaced.
+.xH 2 More on Debugging
+.xH 2 More Exercises
+.IP (3.1)
+You've got a set programs, each of which is created from its own
+assembly-language source file (suffix
+.CW .asm ).
+Each program can be assembled into two versions, one with error-checking
+code assembled in and one without. You could assemble them into files
+with different suffixes
+.CW .eobj \& (
+and
+.CW .obj ,
+for instance), but your linker only understands files that end in
+.CW .obj .
+To top it all off, the final executables
+.I must
+have the suffix
+.CW .exe .
+How can you still use transformation rules to make your life easier
+(Hint: assume the error-checking versions have
+.CW ec
+tacked onto their prefix)?
+.IP (3.2)
+Assume, for a moment or two, you want to perform a sort of
+``indirection'' by placing the name of a variable into another one,
+then you want to get the value of the first by expanding the second
+somehow. Unfortunately, PMake doesn't allow constructs like
+.DS I
+$($(FOO))
+.DE
+What do you do? Hint: no further variable expansion is performed after
+modifiers are applied, thus if you cause a $ to occur in the
+expansion, that's what will be in the result.
+.xH 1 PMake for Gods
+.LP
+This chapter is devoted to those facilities in PMake that allow you to
+do a great deal in a makefile with very little work, as well as do
+some things you couldn't do in Make without a great deal of work (and
+perhaps the use of other programs). The problem with these features,
+is they must be handled with care, or you will end up with a mess.
+.LP
+Once more, I assume a greater familiarity with
+.UX
+or Sprite than I did in the previous two chapters.
+.xH 2 Search Paths
+.Rd 6
+.LP
+PMake supports the dispersal of files into multiple directories by
+allowing you to specify places to look for sources with
+.CW .PATH
+targets in the makefile. The directories you give as sources for these
+targets make up a ``search path.'' Only those files used exclusively
+as sources are actually sought on a search path, the assumption being
+that anything listed as a target in the makefile can be created by the
+makefile and thus should be in the current directory.
+.LP
+There are two types of search paths
+in PMake: one is used for all types of files (including included
+makefiles) and is specified with a plain
+.CW .PATH
+target (e.g.
+.CW ".PATH : RCS" ''), ``
+while the other is specific to a certain type of file, as indicated by
+the file's suffix. A specific search path is indicated by immediately following
+the
+.CW .PATH
+with the suffix of the file. For instance
+.DS
+\&.PATH.h         : /sprite/lib/include /sprite/att/lib/include
+.DE
+would tell PMake to look in the directories
+.CW /sprite/lib/include
+and
+.CW /sprite/att/lib/include
+for any files whose suffix is
+.CW .h .
+.LP
+The current directory is always consulted first to see if a file
+exists. Only if it cannot be found there are the directories in the
+specific search path, followed by those in the general search path,
+consulted.
+.LP
+A search path is also used when expanding wildcard characters. If the
+pattern has a recognizable suffix on it, the path for that suffix will
+be used for the expansion. Otherwise the default search path is employed.
+.LP
+When a file is found in some directory other than the current one, all
+local variables that would have contained the target's name
+.CW .ALLSRC , (
+and
+.CW .IMPSRC )
+will instead contain the path to the file, as found by PMake.
+Thus if you have a file
+.CW ../lib/mumble.c
+and a makefile
+.DS
+\&.PATH.c         : ../lib
+mumble          : mumble.c
+        $(CC) -o $(.TARGET) $(.ALLSRC)
+.DE
+the command executed to create
+.CW mumble
+would be
+.CW "cc -o mumble ../lib/mumble.c" .'' ``
+(As an aside, the command in this case isn't strictly necessary, since
+it will be found using transformation rules if it isn't given. This is because
+.CW .out
+is the null suffix by default and a transformation exists from
+.CW .c
+to
+.CW .out .
+Just thought I'd throw that in.)
+.LP
+If a file exists in two directories on the same search path, the file
+in the first directory on the path will be the one PMake uses. So if
+you have a large system spread over many directories, it would behoove
+you to follow a naming convention that avoids such conflicts.
+.LP
+Something you should know about the way search paths are implemented
+is that each directory is read, and its contents cached, exactly once
+\&\*- when it is first encountered \*- so any changes to the
+directories while PMake is running will not be noted when searching
+for implicit sources, nor will they be found when PMake attempts to
+discover when the file was last modified, unless the file was created in the
+current directory. While people have suggested that PMake should read
+the directories each time, my experience suggests that the caching seldom
+causes problems. In addition, not caching the directories slows things
+down enormously because of PMake's attempts to apply transformation
+rules through non-existent files \*- the number of extra file-system
+searches is truly staggering, especially if many files without
+suffixes are used and the null suffix isn't changed from
+.CW .out .
+.xH 2 Archives and Libraries
+.LP
+.UX
+and Sprite allow you to merge files into an archive using the
+.CW ar
+command. Further, if the files are relocatable object files, you can
+run
+.CW ranlib
+on the archive and get yourself a library that you can link into any
+program you want. The main problem with archives is they double the
+space you need to store the archived files, since there's one copy in
+the archive and one copy out by itself. The problem with libraries is
+you usually think of them as
+.CW -lm
+rather than
+.CW /usr/lib/libm.a
+and the linker thinks they're out-of-date if you so much as look at
+them.
+.LP
+PMake solves the problem with archives by allowing you to tell it to
+examine the files in the archives (so you can remove the individual
+files without having to regenerate them later). To handle the problem
+with libraries, PMake adds an additional way of deciding if a library
+is out-of-date:
+.IP \(bu 2
+If the table of contents is older than the library, or is missing, the
+library is out-of-date.
+.LP
+A library is any target that looks like
+.CW \-l name'' ``
+or that ends in a suffix that was marked as a library using the
+.CW .LIBS
+target.
+.CW .a
+is so marked in the system makefile.
+.LP
+Members of an archive are specified as
+``\fIarchive\fP(\fImember\fP[ \fImember\fP...])''.
+Thus
+.CW libdix.a(window.o) '' ``'
+specifies the file
+.CW window.o
+in the archive
+.CW libdix.a .
+You may also use wildcards to specify the members of the archive. Just
+remember that most the wildcard characters will only find 
+.I existing
+files.
+.LP
+A file that is a member of an archive is treated specially. If the
+file doesn't exist, but it is in the archive, the modification time
+recorded in the archive is used for the file when determining if the
+file is out-of-date. When figuring out how to make an archived member target
+(not the file itself, but the file in the archive \*- the
+\fIarchive\fP(\fImember\fP) target), special care is
+taken with the transformation rules, as follows:
+.IP \(bu 2
+\&\fIarchive\fP(\fImember\fP) is made to depend on \fImember\fP.
+.IP \(bu 2
+The transformation from the \fImember\fP's suffix to the
+\fIarchive\fP's suffix is applied to the \fIarchive\fP(\fImember\fP) target.
+.IP \(bu 2
+The \fIarchive\fP(\fImember\fP)'s
+.CW .TARGET
+variable is set to the name of the \fImember\fP if \fImember\fP is
+actually a target, or the path to the member file if \fImember\fP is
+only a source.
+.IP \(bu 2
+The
+.CW .ARCHIVE
+variable for the \fIarchive\fP(\fImember\fP) target is set to the name
+of the \fIarchive\fP.
+.Ix 0 def variable local .ARCHIVE
+.Ix 0 def .ARCHIVE
+.IP \(bu 2
+The
+.CW .MEMBER
+variable is set to the actual string inside the parentheses. In most
+cases, this will be the same as the
+.CW .TARGET
+variable.
+.Ix 0 def variable local .MEMBER
+.Ix 0 def .MEMBER
+.IP \(bu 2
+The \fIarchive\fP(\fImember\fP)'s place in the local variables of the
+targets that depend on it is taken by the value of its
+.CW .TARGET
+variable.
+.LP
+Thus, a program library could be created with the following makefile:
+.DS
+\&.o.a            :
+        ...
+        rm -f $(.TARGET:T)
+OBJS            = obj1.o obj2.o obj3.o
+libprog.a       : libprog.a($(OBJS))
+        ar cru $(.TARGET) $(.OODATE)
+        ranlib $(.TARGET)
+.DE
+This will cause the three object files to be compiled (if the
+corresponding source files were modified after the object file or, if
+that doesn't exist, the archived object file), the out-of-date ones
+archived in
+.CW libprog.a ,
+a table of contents placed in the archive and the newly-archived
+object files to be removed.
+.LP
+All this is used in the 
+.CW makelib.mk
+system makefile to create a single library with ease. This makefile
+looks like this:
+.DS
+.SM
+#
+# Rules for making libraries. The object files that make up the library are
+# removed once they are archived.
+#
+# To make several libararies in parallel, you should define the variable
+# "many_libraries". This will serialize the invocations of ranlib.
+#
+# To use, do something like this:
+#
+# OBJECTS = <files in the library>
+#
+# fish.a: fish.a($(OBJECTS)) MAKELIB
+#
+#
+
+#ifndef _MAKELIB_MK
+_MAKELIB_MK	=
+
+#include	<po.mk>
+
+\&.po.a .o.a	:
+	...
+	rm -f $(.MEMBER)
+
+ARFLAGS		?= crl
+
+#
+# Re-archive the out-of-date members and recreate the library's table of
+# contents using ranlib. If many_libraries is defined, put the ranlib off
+# til the end so many libraries can be made at once.
+#
+MAKELIB		: .USE .PRECIOUS
+	ar $(ARFLAGS) $(.TARGET) $(.OODATE)
+#ifndef no_ranlib
+# ifdef many_libraries
+	...
+# endif many_libraries
+	ranlib $(.TARGET)
+#endif no_ranlib
+
+#endif _MAKELIB_MK
+.DE
+.xH 2 On the Condition...
+.Rd 1
+.LP
+Like the C compiler before it, PMake allows you to configure the makefile,
+based on the current environment, using conditional statements. A
+conditional looks like this:
+.DS
+#if \fIboolean expression\fP
+\fIlines\fP
+#elif \fIanother boolean expression\fP
+\fImore lines\fP
+#else
+\fIstill more lines\fP
+#endif
+.DE
+They may be nested to a maximum depth of 30 and may occur anywhere
+(except in a comment, of course). The
+.CW # '' ``
+must the very first character on the line.
+.LP
+Each
+.I "boolean expression"
+is made up of terms that look like function calls, the standard C
+boolean operators
+.CW && ,
+.CW || ,
+and
+.CW ! ,
+and the standard relational operators
+.CW == ,
+.CW != ,
+.CW > ,
+.CW >= ,
+.CW < ,
+and
+.CW <= ,
+with
+.CW ==
+and
+.CW !=
+being overloaded to allow string comparisons as well.
+.CW &&
+represents logical AND;
+.CW ||
+is logical OR and
+.CW !
+is logical NOT.  The arithmetic and string operators take precedence
+over all three of these operators, while NOT takes precedence over
+AND, which takes precedence over OR.  This precedence may be
+overridden with parentheses, and an expression may be parenthesized to
+your heart's content.  Each term looks like a call on one of four
+functions:
+.nr pw 9
+.Ix 0 def make
+.Ix 0 def conditional make
+.Ix 0 def if make
+.IP make \n(pw
+The syntax is
+.CW make( \fItarget\fP\c
+.CW )
+where
+.I target
+is a target in the makefile. This is true if the given target was
+specified on the command line, or as the source for a
+.CW .MAIN
+target (note that the sources for
+.CW .MAIN
+are only used if no targets were given on the command line).
+.IP defined \n(pw
+.Ix 0 def defined
+.Ix 0 def conditional defined
+.Ix 0 def if defined
+The syntax is
+.CW defined( \fIvariable\fP\c
+.CW )
+and is true if
+.I variable
+is defined. Certain variables are defined in the system makefile that
+identify the system on which PMake is being run.
+.IP exists \n(pw
+.Ix 0 def exists
+.Ix 0 def conditional exists
+.Ix 0 def if exists
+The syntax is
+.CW exists( \fIfile\fP\c
+.CW )
+and is true if the file can be found on the global search path (i.e.
+that defined by
+.CW .PATH
+targets, not by
+.CW .PATH \fIsuffix\fP
+targets).
+.IP empty \n(pw
+.Ix 0 def empty
+.Ix 0 def conditional empty
+.Ix 0 def if empty
+This syntax is much like the others, except the string inside the
+parentheses is of the same form as you would put between parentheses
+when expanding a variable, complete with modifiers and everything. The
+function returns true if the resulting string is empty (NOTE: an undefined
+variable in this context will cause at the very least a warning
+message about a malformed conditional, and at the worst will cause the
+process to stop once it has read the makefile. If you want to check
+for a variable being defined or empty, use the expression
+.CW !defined( \fIvar\fP\c ``
+.CW ") || empty(" \fIvar\fP\c
+.CW ) ''
+as the definition of
+.CW ||
+will prevent the
+.CW empty()
+from being evaluated and causing an error, if the variable is
+undefined). This can be used to see if a variable contains a given
+word, for example:
+.DS
+#if !empty(\fIvar\fP:M\fIword\fP)
+.DE
+.LP
+The arithmetic and string operators may only be used to test the value
+of a variable. The lefthand side must contain the variable expansion,
+while the righthand side contains either a string, enclosed in
+double-quotes, or a number. The standard C numeric conventions (except
+for specifying an octal number) apply to both sides. E.g.
+.DS
+#if $(OS) == 4.3
+
+#if $(MACHINE) == "sun3"
+
+#if $(LOAD_ADDR) < 0xc000
+.DE
+are all valid conditionals. In addition, the numeric value of a
+variable can be tested as a boolean as follows:
+.DS
+#if $(LOAD)
+.DE
+would see if
+.CW LOAD
+contains a non-zero value and
+.DS
+#if !$(LOAD)
+.DE
+would test if
+.CW LOAD
+contains a zero value.
+.LP
+In addition to the bare
+.CW #if ,'' ``
+there are other forms that apply one of the first two functions to each
+term. They are as follows:
+.DS
+	ifdef	\fRdefined\fP
+	ifndef	\fR!defined\fP
+	ifmake	\fRmake\fP
+	ifnmake	\fR!make\fP
+.DE
+There are also the ``else if'' forms:
+.CW elif ,
+.CW elifdef ,
+.CW elifndef ,
+.CW elifmake ,
+and
+.CW elifnmake .
+.LP
+For instance, if you wish to create two versions of a program, one of which
+is optimized (the production version) and the other of which is for debugging
+(has symbols for dbx), you have two choices: you can create two
+makefiles, one of which uses the
+.CW \-g
+flag for the compilation, while the other uses the
+.CW \-O
+flag, or you can use another target (call it
+.CW debug )
+to create the debug version. The construct below will take care of
+this for you. I have also made it so defining the variable
+.CW DEBUG
+(say with
+.CW "pmake -D DEBUG" )
+will also cause the debug version to be made.
+.DS
+#if defined(DEBUG) || make(debug)
+CFLAGS		+= -g
+#else
+CFLAGS		+= -O
+#endif
+.DE
+There are, of course, problems with this approach. The most glaring
+annoyance is that if you want to go from making a debug version to
+making a production version, you have to remove all the object files,
+or you will get some optimized and some debug versions in the same
+program. Another annoyance is you have to be careful not to make two
+targets that ``conflict'' because of some conditionals in the
+makefile. For instance
+.DS
+#if make(print)
+FORMATTER	= ditroff -Plaser_printer
+#endif
+#if make(draft)
+FORMATTER	= nroff -Pdot_matrix_printer
+#endif
+.DE
+would wreak havok if you tried
+.CW "pmake draft print" '' ``
+since you would use the same formatter for each target. As I said,
+this all gets somewhat complicated.
+.xH 2 A Shell is a Shell is a Shell
+.Rd 7
+.LP
+In normal operation, the Bourne Shell (better known as
+.CW sh '') ``
+is used to execute the commands to re-create targets. PMake also allows you
+to specify a different shell for it to use when executing these
+commands. There are several things PMake must know about the shell you
+wish to use. These things are specified as the sources for the
+.CW .SHELL
+.Ix 0 ref .SHELL
+.Ix 0 ref target .SHELL
+target by keyword, as follows:
+.IP "\fBpath=\fP\fIpath\fP"
+PMake needs to know where the shell actually resides, so it can
+execute it. If you specify this and nothing else, PMake will use the
+last component of the path and look in its table of the shells it
+knows and use the specification it finds, if any. Use this if you just
+want to use a different version of the Bourne or C Shell (yes, PMake knows
+how to use the C Shell too).
+.IP "\fBname=\fP\fIname\fP"
+This is the name by which the shell is to be known. It is a single
+word and, if no other keywords are specified (other than
+.B path ),
+it is the name by which PMake attempts to find a specification for
+it (as mentioned above). You can use this if you would just rather use
+the C Shell than the Bourne Shell
+.CW ".SHELL: name=csh" '' (``
+will do it).
+.IP "\fBquiet=\fP\fIecho-off command\fP"
+As mentioned before, PMake actually controls whether commands are
+printed by introducing commands into the shell's input stream. This
+keyword, and the next two, control what those commands are. The
+.B quiet
+keyword is the command used to turn echoing off. Once it is turned
+off, echoing is expected to remain off until the echo-on command is given.
+.IP "\fBecho=\fP\fIecho-on command\fP"
+The command PMake should give to turn echoing back on again.
+.IP "\fBfilter=\fP\fIprinted echo-off command\fP"
+Many shells will echo the echo-off command when it is given. This
+keyword tells PMake in what format the shell actually prints the
+echo-off command. Wherever PMake sees this string in the shell's
+output, it will delete it and any following whitespace, up to and
+including the next newline. See the example at the end of this section
+for more details.
+.IP "\fBechoFlag=\fP\fIflag to turn echoing on\fP"
+Unless a target has been marked
+.CW .SILENT ,
+PMake wants to start the shell running with echoing on. To do this, it
+passes this flag to the shell as one of its arguments. If either this
+or the next flag begins with a `\-', the flags will be passed to the
+shell as separate arguments. Otherwise, the two will be concatenated
+(if they are used at the same time, of course).
+.IP "\fBerrFlag=\fP\fIflag to turn error checking on\fP"
+Likewise, unless a target is marked
+.CW .IGNORE ,
+PMake wishes error-checking to be on from the very start. To this end,
+it will pass this flag to the shell as an argument. The same rules for
+an initial `\-' apply as for the
+.B echoFlag .
+.IP "\fBcheck=\fP\fIcommand to turn error checking on\fP"
+Just as for echo-control, error-control is achieved by inserting
+commands into the shell's input stream. This is the command to make
+the shell check for errors. It also serves another purpose if the
+shell doesn't have error-control as commands, but I'll get into that
+in a minute. Again, once error checking has been turned on, it is
+expected to remain on until it is turned off again.
+.IP "\fBignore=\fP\fIcommand to turn error checking off\fP"
+This is the command PMake uses to turn error checking off. It has
+another use if the shell doesn't do error-control, but I'll tell you
+about that.\|.\|.\|now.
+.IP "\fBhasErrCtl=\fP\fIyes or no\fP"
+This takes a value that is either
+.B yes
+or
+.B no .
+Now you might think that the existence of the
+.B check
+and
+.B ignore
+keywords would be enough to tell PMake if the shell can do
+error-control, but you'd be wrong. If
+.B hasErrCtl
+is
+.B yes ,
+PMake uses the check and ignore commands in a straight-forward manner.
+If this is
+.B no ,
+however, their use is rather different. In this case, the check
+command is used as a template, in which the string
+.B %s
+is replaced by the command that's about to be executed, to produce a
+command for the shell that will echo the command to be executed. The
+ignore command is also used as a template, again with
+.B %s
+replaced by the command to be executed, to produce a command that will
+execute the command to be executed and ignore any error it returns.
+When these strings are used as templates, you must provide newline(s)
+.CW \en '') (``
+in the appropriate place(s).
+.LP
+The strings that follow these keywords may be enclosed in single or
+double quotes (the quotes will be stripped off) and may contain the
+usual C backslash-characters (\en is newline, \er is return, \eb is
+backspace, \e' escapes a single-quote inside single-quotes, \e"
+escapes a double-quote inside double-quotes). Now for an example.
+.LP
+This is actually the contents of the
+.CW <shx.mk>
+system makefile, and causes PMake to use the Bourne Shell in such a
+way that each command is printed as it is executed. That is, if more
+than one command is given on a line, each will be printed separately.
+Similarly, each time the body of a loop is executed, the commands
+within that loop will be printed, etc. The specification runs like
+this:
+.DS
+#
+# This is a shell specification to have the bourne shell echo
+# the commands just before executing them, rather than when it reads
+# them. Useful if you want to see how variables are being expanded, etc.
+#
+\&.SHELL 	: path=/bin/sh \e
+	quiet="set -" \e
+	echo="set -x" \e
+	filter="+ set - " \e
+	echoFlag=x \e
+	errFlag=e \e
+	hasErrCtl=yes \e
+	check="set -e" \e
+	ignore="set +e"
+.DE
+.LP
+It tells PMake the following:
+.Bp
+The shell is located in the file
+.CW /bin/sh .
+It need not tell PMake that the name of the shell is
+.CW sh 
+as PMake can figure that out for itself (it's the last component of
+the path).
+.Bp
+The command to stop echoing is
+.CW "set -" .
+.Bp
+The command to start echoing is
+.CW "set -x" .
+.Bp
+When the echo off command is executed, the shell will print
+.CW "+ set - " 
+(The `+' comes from using the
+.CW \-x
+flag (rather than the
+.CW \-v
+flag PMake usually uses)). PMake will remove all occurences of this
+string from the output, so you don't notice extra commands you didn't
+put there.
+.Bp
+The flag the Bourne Shell will take to start echoing in this way is
+the
+.CW \-x
+flag. The Bourne Shell will only take its flag arguments concatenated
+as its first argument, so neither this nor the
+.B errFlag
+specification begins with a \-.
+.Bp
+The flag to use to turn error-checking on from the start is
+.CW \-e .
+.Bp
+The shell can turn error-checking on and off, and the commands to do
+so are
+.CW "set +e"
+and
+.CW "set -e" ,
+respectively.
+.LP
+I should note that this specification is for Bourne Shells that are
+not part of Berkeley
+.UX ,
+as shells from Berkeley don't do error control. You can get a similar
+effect, however, by changing the last three lines to be:
+.DS
+	hasErrCtl=no \e
+	check="echo \e"+ %s\e"\en" \e
+	ignore="sh -c '%s || exit 0\en"
+.DE
+.LP
+This will cause PMake to execute the two commands
+.DS
+echo "+ \fIcmd\fP"
+sh -c '\fIcmd\fP || true'
+.DE
+for each command for which errors are to be ignored. (In case you are
+wondering, the thing for
+.CW ignore
+tells the shell to execute another shell without error checking on and
+always exit 0, since the
+.B ||
+causes the
+.CW "exit 0"
+to be executed only if the first command exited non-zero, and if the
+first command exited zero, the shell will also exit zero, since that's
+the last command it executed).
+.xH 2 Compatibility
+.Ix 0 ref compatibility
+.LP
+There are three (well, 3 \(12) levels of backwards-compatibility built
+into PMake.  Most makefiles will need none at all. Some may need a
+little bit of work to operate correctly when run in parallel. Each
+level encompasses the previous levels (e.g.
+.B \-B
+(one shell per command) implies
+.B \-V )
+The three levels are described in the following three sections.
+.xH 3 DEFCON 3 \*- Variable Expansion
+.Ix 0 ref compatibility
+.LP
+As noted before, PMake will not expand a variable unless it knows of a
+value for it. This can cause problems for makefiles that expect to
+leave variables undefined except in special circumstances (e.g. if
+more flags need to be passed to the C compiler or the output from a
+text processor should be sent to a different printer). If the
+variables are enclosed in curly braces
+.CW ${PRINTER} ''), (``
+the shell will let them pass. If they are enclosed in parentheses,
+however, the shell will declare a syntax error and the make will come
+to a grinding halt.
+.LP
+You have two choices: change the makefile to define the variables
+(their values can be overridden on the command line, since that's
+where they would have been set if you used Make, anyway) or always give the
+.B \-V
+flag (this can be done with the
+.CW .MAKEFLAGS
+target, if you want).
+.xH 3 DEFCON 2 \*- The Number of the Beast
+.Ix 0 ref compatibility
+.LP
+Then there are the makefiles that expect certain commands, such as
+changing to a different directory, to not affect other commands in a
+target's creation script. You can solve this is either by going
+back to executing one shell per command (which is what the
+.B \-B
+flag forces PMake to do), which slows the process down a good bit and
+requires you to use semicolons and escaped newlines for shell constructs, or
+by changing the makefile to execute the offending command(s) in a subshell
+(by placing the line inside parentheses), like so:
+.DS
+install :: .MAKE
+	(cd src; $(.PMAKE) install)
+	(cd lib; $(.PMAKE) install)
+	(cd man; $(.PMAKE) install)
+.DE
+.Ix 0 ref operator double-colon
+.Ix 0 ref variable global .PMAKE
+.Ix 0 ref .PMAKE
+.Ix 0 ref .MAKE
+.Ix 0 ref attribute .MAKE
+This will always execute the three makes (even if the
+.B \-n
+flag was given) because of the combination of the ``::'' operator and
+the
+.CW .MAKE
+attribute. Each command will change to the proper directory to perform
+the install, leaving the main shell in the directory in which it started.
+.xH 3 "DEFCON 1 \*- Imitation is the Not the Highest Form of Flattery"
+.Ix 0 ref compatibility
+.LP
+The final category of makefile is the one where every command requires
+input, the dependencies are incompletely specified, or you simply
+cannot create more than one target at a time, as mentioned earlier. In
+addition, you may not have the time or desire to upgrade the makefile
+to run smoothly with PMake. If you are the conservative sort, this is
+the compatibility mode for you. It is entered either by giving PMake
+the
+.B \-M
+flag (for Make), or by executing PMake as
+.CW make .'' ``
+In either case, PMake performs things exactly like Make (while still
+supporting most of the nice new features PMake provides). This
+includes:
+.IP \(bu 2
+No parallel execution.
+.IP \(bu 2
+Targets are made in the exact order specified by the makefile. The
+sources for each target are made in strict left-to-right order, etc.
+.IP \(bu 2
+A single Bourne shell is used to execute each command, thus the
+shell's
+.CW $$
+variable is useless, changing directories doesn't work across command
+lines, etc.
+.IP \(bu 2
+If no special characters exist in a command line, PMake will break the
+command into words itself and execute the command directly, without
+executing a shell first. The characters that cause PMake to execute a
+shell are:
+.CW # ,
+.CW = ,
+.CW | ,
+.CW ^ ,
+.CW ( ,
+.CW ) ,
+.CW { ,
+.CW } ,
+.CW ; ,
+.CW & ,
+.CW < ,
+.CW > ,
+.CW * ,
+.CW ? ,
+.CW [ ,
+.CW ] ,
+.CW : ,
+.CW $ ,
+.CW ` ,
+and
+.CW \e .
+You should notice that these are all the characters that are given
+special meaning by the shell (except
+.CW '
+and
+.CW " ,
+which PMake deals with all by its lonesome).
+.IP \(bu 2
+The use of the null suffix is turned off.
+.Ix 0 ref "null suffix"
+.Ix 0 ref suffix null
+.xH 2 The Way Things Work
+.LP
+When PMake reads the makefile, it parses sources and targets into
+nodes in a graph. The graph is directed only in the sense that PMake
+knows which way is up. Each node contains not only links to all its
+parents and children (the nodes that depend on it and those on which
+it depends, respectively), but also a count of the number of its
+children that have already been processed.
+.LP
+The most important thing to know about how PMake uses this graph is
+that the traversal is breadth-first and occurs in two passes.
+.LP
+After PMake has parsed the makefile, it begins with the nodes the user
+has told it to make (either on the command line, or via a 
+.CW .MAIN
+target, or by the target being the first in the file not labeled with
+the
+.CW .NOTMAIN
+attribute) placed in a queue. It continues to take the node off the
+front of the queue, mark it as something that needs to be made, pass
+the node to 
+.CW Suff_FindDeps
+(mentioned earlier) to find any implicit sources for the node, and
+place all the node's children that have yet to be marked at the end of
+the queue. If any of the children is a
+.CW .USE
+rule, its attributes are applied to the parent, then its commands are
+appended to the parent's list of commands and its children are linked
+to its parent. The parent's unmade children counter is then decremented
+(since the
+.CW .USE
+node has been processed). You will note that this allows a
+.CW .USE
+node to have children that are
+.CW .USE
+nodes and the rules will be applied in sequence.
+If the node has no children, it is placed at the end of
+another queue to be examined in the second pass. This process
+continues until the first queue is empty.
+.LP
+At this point, all the leaves of the graph are in the examination
+queue. PMake removes the node at the head of the queue and sees if it
+is out-of-date. If it is, it is passed to a function that will execute
+the commands for the node asynchronously. When the commands have
+completed, all the node's parents have their unmade children counter
+decremented and, if the counter is then 0, they are placed on the
+examination queue. Likewise, if the node is up-to-date. Only those
+parents that were marked on the downward pass are processed in this
+way. Thus PMake traverses the graph back up to the nodes the user
+instructed it to create. When the examination queue is empty and no
+shells are running to create a target, PMake is finished.
+.LP
+Once all targets have been processed, PMake executes the commands
+attached to the
+.CW .END
+target, either explicitly or through the use of an ellipsis in a shell
+script. If there were no errors during the entire process but there
+are still some targets unmade (PMake keeps a running count of how many
+targets are left to be made), there is a cycle in the graph. PMake does
+a depth-first traversal of the graph to find all the targets that
+weren't made and prints them out one by one.
+.xH 1 Answers to Exercises
+.IP (3.1)
+This is something of a trick question, for which I apologize. The
+trick comes from the UNIX definition of a suffix, which PMake doesn't
+necessarily share. You will have noticed that all the suffixes used in
+this tutorial (and in UNIX in general) begin with a period
+.CW .ms , (
+.CW .c ,
+etc.). Now, PMake's idea of a suffix is more like English's: it's the
+characters at the end of a word. With this in mind, one possible
+.Ix 0 def suffix
+solution to this problem goes as follows:
+.DS I
+\&.SUFFIXES       : ec.exe .exe ec.obj .obj .asm
+ec.objec.exe .obj.exe :
+        link -o $(.TARGET) $(.IMPSRC)
+\&.asmec.obj      :
+        asm -o $(.TARGET) -DDO_ERROR_CHECKING $(.IMPSRC)
+\&.asm.obj        :
+        asm -o $(.TARGET) $(.IMPSRC)
+.DE
+.IP (3.2)
+The trick to this one lies in the ``:='' variable-assignment operator
+and the ``:S'' variable-expansion modifier. 
+.Ix 0 ref variable assignment expanded
+.Ix 0 ref variable expansion modified
+.Ix 0 ref modifier substitute
+.Ix 0 ref :S
+.Ix 0 ref :=
+Basically what you want is to take the pointer variable, so to speak,
+and transform it into an invocation of the variable at which it
+points. You might try something like
+.DS I
+$(PTR:S/^/\e$(/:S/$/))
+.DE
+which places
+.CW $( '' ``
+at the front of the variable name and
+.CW ) '' ``
+at the end, thus transforming
+.CW VAR ,'' ``
+for example, into
+.CW $(VAR) ,'' ``
+which is just what we want. Unfortunately (as you know if you've tried
+it), since, as it says in the hint, PMake does no further substitution
+on the result of a modified expansion, that's \fIall\fP you get. The
+solution is to make use of ``:='' to place that string into yet
+another variable, then invoke the other variable directly:
+.DS I
+*PTR            := $(PTR:S/^/\e$(/:S/$/)/)
+.DE
+You can then use
+.CW $(*PTR) '' ``
+to your heart's content.
+.de Gp
+.XP
+\&\fB\\$1:\fP
+..
+.xH 1 Glossary of Jargon
+.Gp "attribute"
+A property given to a target that causes PMake to treat it differently.
+.Gp "command script"
+The lines immediately following a dependency line that specify
+commands to execute to create each of the targets on the dependency
+line. Each line in the command script must begin with a tab.
+.Gp "command-line variable"
+A variable defined in an argument when PMake is first executed.
+Overrides all assignments to the same variable name in the makefile.
+.Gp "conditional"
+A construct much like that used in C that allows a makefile to be
+configured on the fly based on the local environment, or on what is being
+made by that invocation of PMake.
+.Gp "creation script"
+Commands used to create a target. See ``command script.''
+.Gp "dependency"
+The relationship between a source and a target. This comes in three
+flavors, as indicated by the operator between the target and the
+source. `:' gives a straight time-wise dependency (if the target is
+older than the source, the target is out-of-date), while `!' provides
+simply an ordering and always considers the target out-of-date. `::'
+is much like `:', save it creates multiple instances of a target each
+of which depends on its own list of sources.
+.Gp "dynamic source"
+This refers to a source that has a local variable invocation in it. It
+allows a single dependency line to specify a different source for each
+target on the line.
+.Gp "global variable"
+Any variable defined in a makefile. Takes precedence over variables
+defined in the environment, but not over command-line or local variables.
+.Gp "input graph"
+What PMake constructs from a makefile. Consists of nodes made of the
+targets in the makefile, and the links between them (the
+dependencies). The links are directed (from source to target) and
+there may not be any cycles (loops) in the graph.
+.Gp "local variable"
+A variable defined by PMake visible only in a target's shell script.
+There are seven local variables, not all of which are defined for
+every target:
+.CW .TARGET ,
+.CW .ALLSRC ,
+.CW .OODATE ,
+.CW .PREFIX ,
+.CW .IMPSRC ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER .
+.CW .TARGET ,
+.CW .PREFIX ,
+.CW .ARCHIVE ,
+and 
+.CW .MEMBER
+may be used on dependency lines to create ``dynamic sources.''
+.Gp "makefile"
+A file that describes how a system is built. If you don't know what it
+is after reading this tutorial.\|.\|.\|.
+.Gp "modifier"
+A letter, following a colon, used to alter how a variable is expanded.
+It has no effect on the variable itself.
+.Gp "operator"
+What separates a source from a target (on a dependency line) and specifies
+the relationship between the two. There are three:
+.CW : ', `
+.CW :: ', `
+and
+.CW ! '. `
+.Gp "search path"
+A list of directories in which a file should be sought. PMake's view
+of the contents of directories in a search path does not change once
+the makefile has been read. A file is sought on a search path only if
+it is exclusively a source.
+.Gp "shell"
+A program to which commands are passed in order to create targets.
+.Gp "source"
+Anything to the right of an operator on a dependency line. Targets on
+the dependency line are usually created from the sources.
+.Gp "special target"
+A target that causes PMake to do special things when it's encountered.
+.Gp "suffix"
+The tail end of a file name. Usually begins with a period,
+.CW .c
+or
+.CW .ms ,
+e.g.
+.Gp "target"
+A word to the left of the operator on a dependency line. More
+generally, any file that PMake might create. A file may be (and often
+is) both a target and a source (what it is depends on how PMake is
+looking at it at the time \*- sort of like the wave/particle duality
+of light, you know).
+.Gp "transformation rule"
+A special construct in a makefile that specifies how to create a file
+of one type from a file of another, as indicated by their suffixes.
+.Gp "variable expansion"
+The process of substituting the value of a variable for a reference to
+it. Expansion may be altered by means of modifiers.
+.Gp "variable"
+A place in which to store text that may be retrieved later. Also used
+to define the local environment. Conditionals exist that test whether
+a variable is defined or not.
+.bp
+.\" Output table of contents last, with an entry for the index, making
+.\" sure to save and restore the last real page number for the index...
+.nr @n \n(PN+1
+.\" We are not generating an index
+.\" .XS \n(@n
+.\" Index
+.\" .XE
+.nr %% \n%
+.PX
+.nr % \n(%%