getopt.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 81 行

.TH getopt 1
.SH Name
getopt \- parse command options
.SH Syntax
.NXR "getopt command"
.B set \- \- \*\`getopt optstring
.B $\(**\*\`
.SH Description
.NXR "getopt command"
The
.PN getopt
command
breaks up options in command lines for easy parsing by Shell
procedures and checks for legal options.
The
.B optstring
option letters are recognized
if a letter is followed by a colon, the option
expects an argument which may or
may not be separated from it by white space.
For further information, see 
.MS getopt 3 .
.PP
The special option, specified by two minus signs (\- \-), 
delimits the end of the
options.  If the delimiters are used explicitly, 
.PN getopt
recognizes it;
otherwise,
.PN getopt
generates it.
In either case,
.PN getopt
places the delimiter at the end of the options.
The positional parameters ($1 $2 ...) of the shell are reset
so that each option
is preceded by a single minus sign (\-) and is in its own positional 
parameter; each option argument is also parsed into its own positional 
parameter.
.SH Examples
The following code fragment shows how you can process the arguments
for a command that can take the options
.B a
or
.B b,
as well as the option
.B o,
which requires an argument:
.EX
#!/bin/sh5
set \-\- \*\`getopt abo: $\(**\*\`
if [ $? != 0 ]
then
	echo $\s-1USAGE\s+1
	exit 2
fi
for i in $\(**
do
	case $i in
	\-a \(bv \-b)	\s-1FLAG\s+1=$i; shift;;
	\-o)	\s-1OARG\s+1=$2; shift 2;;
	\-\-)	shift; break;;
	esac
done
.EE
This code accepts any of the following as equivalent:
.EX
cmd \-aoarg file file
cmd \-a \-o arg file file
cmd \-oarg \-a file file
cmd \-a \-oarg \-\- file file
.EE
.SH Diagnostics
The
.PN getopt
command prints an error message on the standard error
when it encounters an option letter not included in
.IR optstring .
.SH See Also
sh5(1), getopt(3)