Module Name: src
Committed By: wiz
Date: Sun Aug 12 17:27:05 UTC 2012
Modified Files:
src/bin/expr: expr.1
Log Message:
Improvements: wording, punctuation, macro usage.
>From patch by Bug Hunting.
To generate a diff of this commit:
cvs rdiff -u -r1.32 -r1.33 src/bin/expr/expr.1
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/bin/expr/expr.1
diff -u src/bin/expr/expr.1:1.32 src/bin/expr/expr.1:1.33
--- src/bin/expr/expr.1:1.32 Wed May 9 22:29:06 2012
+++ src/bin/expr/expr.1 Sun Aug 12 17:27:04 2012
@@ -1,4 +1,4 @@
-.\" $NetBSD: expr.1,v 1.32 2012/05/09 22:29:06 jdf Exp $
+.\" $NetBSD: expr.1,v 1.33 2012/08/12 17:27:04 wiz Exp $
.\"
.\" Copyright (c) 2000,2003 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -145,18 +145,23 @@ an error occurred (such as memory alloca
.Sh EXAMPLES
.Bl -enum
.It
-The following example adds one to the variable a.
+The following example adds one to variable
+.Dq a :
.Dl a=`expr $a + 1`
.It
The following example returns zero, due to subtraction having higher precedence
-than '\*[Am]' operator.
+than the
+.Dq \*[Am]
+operator:
.Dl expr 1 '\*[Am]' 1 - 1
.It
The following example returns the filename portion of a pathname stored
-in variable a.
+in variable
+.Dq a :
.Dl expr "/$a" Li : '.*/\e(.*\e)'
.It
-The following example returns the number of characters in variable a.
+The following example returns the number of characters in variable
+.Dq a :
.Dl expr $a Li : '.*'
.El
.Sh COMPATIBILITY
@@ -164,8 +169,11 @@ This implementation of
.Nm
internally uses 64 bit representation of integers and checks for
over- and underflows.
-It also treats / (division mark) and
-option '--' correctly depending upon context.
+It also treats
+.Dq /
+(the division mark) and option
+.Dq --
+correctly depending upon context.
.Pp
.Nm
on other systems (including
@@ -182,12 +190,16 @@ can only process values between -2147483
On other systems,
.Nm
might also not work correctly for regular expressions where
-either side contains single forward slash, like this:
+either side contains
+.Dq /
+(a single forward slash), like this:
.Bd -literal -offset indent
expr / : '.*/\e(.*\e)'
.Ed
.Pp
-If this is the case, you might use // (double forward slash)
+If this is the case, you might use
+.Dq //
+(a double forward slash)
to avoid confusion with the division operator:
.Bd -literal -offset indent
expr "//$a" : '.*/\e(.*\e)'
@@ -196,11 +208,13 @@ expr "//$a" : '.*/\e(.*\e)'
According to
.St -p1003.2 ,
.Nm
-has to recognize special option '--', treat it as an end of command
-line options and ignore it.
+has to recognize special option
+.Dq -- ,
+treat it as a delimiter to mark the end of command
+line options, and ignore it.
Some
.Nm
-implementations don't recognize it at all, others
+implementations don't recognize it at all; others
might ignore it even in cases where doing so results in syntax
error.
There should be same result for both following examples,
@@ -215,7 +229,9 @@ Although
.Nx
.Nm
handles both cases correctly, you should not depend on this behavior
-for portability reasons and avoid passing bare '--' as first
+for portability reasons and avoid passing a bare
+.Dq --
+as the first
argument.
.Sh STANDARDS
The
