diff options
Diffstat (limited to 'bin')
| -rw-r--r-- | bin/expr/expr.1 | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/bin/expr/expr.1 b/bin/expr/expr.1 index be6bf24b455..1a95bf52868 100644 --- a/bin/expr/expr.1 +++ b/bin/expr/expr.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: expr.1,v 1.7 1999/06/04 02:45:13 aaron Exp $ +.\" $OpenBSD: expr.1,v 1.8 1999/09/23 10:43:07 aaron Exp $ .\" $NetBSD: expr.1,v 1.9 1995/04/28 23:27:13 jtc Exp $ .\" .\" Written by J.T. Conklin <jtc@netbsd.org>. @@ -19,7 +19,6 @@ The utility evaluates .Ar expression and writes the result on standard output. -.Pp All operators are separate arguments to the .Nm utility. @@ -51,14 +50,14 @@ Returns the results of addition or subtraction of integer-valued arguments. Returns the results of multiplication, integer division, or remainder of integer-valued arguments. .It Ar expr1 Li : Ar expr2 The -.Dq \: +.Ql \&: operator matches .Ar expr1 against .Ar expr2 , which must be a regular expression. The regular expression is anchored to the beginning of the string with an implicit -.Dq ^ . +.Ql ^ . .Pp If the match succeeds and the pattern contains at least one regular expression subexpression @@ -66,27 +65,33 @@ expression subexpression the string corresponding to .Dq "\e1" is returned; -otherwise the matching operator returns the number of characters matched. +otherwise, the matching operator returns the number of characters matched. If the match fails and the pattern contains a regular expression subexpression the null string is returned; -otherwise 0. +otherwise, returns 0. .El .Pp Parentheses are used for grouping in the usual manner. .Sh EXAMPLES -.Bl -enum -.It -The following example adds one to the variable a. +Add 1 to the variable +.Va a : +.Pp .Dl a=`expr $a + 1` -.It -The following example returns the filename portion of a pathname stored -in variable a. The // characters act to eliminate ambiguity with the -division operator. +.Pp +Return the filename portion of a pathname stored +in variable +.Va a . +The +.Ql // +characters act to eliminate ambiguity with the division operator. +.Pp .Dl expr "//$a" Li : '.*/\e(.*\e)' -.It -The following example returns the number of characters in variable a. +.Pp +Return the number of characters in variable +.Va a : +.Pp .Dl expr $a Li : '.*' -.El +.Pp .Sh DIAGNOSTICS The .Nm @@ -102,6 +107,8 @@ The expression is invalid. .It >2 An error occurred (such as memory allocation failure). .El +.Sh SEE ALSO +.Xr test 1 .Sh STANDARDS The .Nm |