
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 (-
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 modi®ed command line to the standard output.
EXTERNAL INFLUENCES
Environment Variables
LC_MESSAGES determines the language in which messages are displayed.
If LC_MESSAGES is not speci®ed in the environment or is set to the empty string, the value of LANG is used as a default for each unspeci®ed or empty variable.
If LANG is not speci®ed 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 internationalization variables are set to "C". See environ(5).
International Code Set Support
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
if [ $?
fi
while [ $#
;;
OARG=$2 shift 2
;;
shift break
;;
esac
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