HP-UX Reference (11i v1 05/09) - 1 User Commands A-M (vol 1)

g
getopt(1) getopt(1)
NAME
getopt - parse command options
SYNOPSIS
getopt optstring args
DESCRIPTION
getopt is used to break up options in command lines for easy parsing by shell procedures and to check for
legal options. optstring is a string of recognized option letters (see getopt(3C)). If a letter is followed by a
colon, the option is expected to have an argument which may or may not be separated from it by white
space.
The positional parameters ($1 $2 ... ) of the shell are reset so that each option is preceded by a
- and is in
its own positional parameter; each option argument is also parsed into its own positional parameter.
getopt recognizes two hyphens (--
) to delimit the end of the options. If absent, getopt places -- at
the end of the options.
The most common use of
getopt is in the shell’s
set command (see the example below) where
getopt converts the command line to a more easily parsed form. getopt writes the modified com-
mand line to the standard output.
EXTERNAL INFLUENCES
Environment Variables
LC_MESSAGES determines the language in which messages are displayed.
If LC_MESSAGES is not specified in the environment or is set to the empty string, the value of
LANG is
used as a default for each unspecified or empty variable.
If
LANG is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of
LANG.
If any internationalization variable contains an invalid setting,
getopt behaves as if all internationaliza-
tion variables are set to "C". See environ(5).
International Code Set Support
Single-byte and multi-byte character code sets are supported.
DIAGNOSTICS
getopt prints an error message on the standard error when it encounters an option letter not included in
optstring.
EXAMPLES
The following code fragment processes the arguments for a command that can take the options a or
b, and
the option
o which requires an argument:
set -- ‘getopt abo: $*‘
if [ $? -ne 0 ]; then
echo $USAGE
exit 2
fi
while [ $# -gt 0 ]; do
case $1 in
-a | -b)
FLAG=$1
shift
;;
-o)
OARG=$2
shift 2
;;
--)
shift
break
;;
esac
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 1−−341