shell-getopt.md

shell-getopt(3)

NAME

getopt, getoptex, getopts, getsubopt - parses command options (enhanced)

SYNOPSIS

• getopt optstring parameters
• getopt [options] [--] optstring parameters
• getopt [options] -o|--options optstring [options] [--] parameters
• getsubopt optstring parameters
• getopts optstring name [args]
• getoptex optstring name [args]

DESCRIPTION

Collection of functions to parse commend line options.

getopt

This function is used to parse command line options and to check for legal options. Shell implementation of getopt (1) utility from the util-linux package. This function is written to be as compatible as possible with getopt (1) utility. Usually you can just replace getopt (1) without any modifications by this function.

Example:

TEMP=`getopt -n "$PROG" -o "v:,V,h" -l "verbose:,version,help" -- "$@"` || show_usage
eval set -- "$TEMP"

while :; do
    case "$1" in
        -h|--help) show_help
            ;;
        -v|--verbose) shift; verbose="$1"
            ;;
        -V|--version) print_version "$PROG"
            ;;
        *) fatal "Unrecognized option: $1"
            ;;
    esac
    shift
done

getsubopt

Function parses suboption arguments from a string. This is a shell-implementation of getsubopt (3).

Example:

while getsubopt 'rw mode: path: dev:' 'rw,mode=755,path="/zzz xxx",dev=/dev/zzz'; do
    echo "Option <$OPTOPT> ${OPTARG:+has an arg <$OPTARG>}"
done

getopts

Shell implementation of getopts (1) utility. It's a built-in utility in some shells.

Example:

echo "Using getopt to parse arguments:"

while getopts "abcd:e." "$@"; do
    echo "Option <$OPTOPT> ${OPTARG:+has an arg <$OPTARG>}"
done

shift $(($OPTIND-1))
set -- $@ ${OPTUKN-}

for arg in "$@"; do
    echo "Non option argument <$arg>"
done

getoptex

This function is the same as getopts, but supports long options.

Example:

echo Using getoptex to parse arguments:

while getoptex "a; b; c; d: e. opt1 opt2 opt3 opt4: opt5." "$@"; do
    echo "Option <$OPTOPT> ${OPTARG:+has an arg <$OPTARG>}"
done

shift $(($OPTIND-1))
set -- $@ ${OPTUKN-}

for arg in "$@"; do
    echo "Non option argument <$arg>"
done

ENVIRONMENT

GETOPT_ALLOW_UNKNOWN - Ignore unknown options.

GETOPT_ALLOW_ABBREV - Long options may be abbreviated, as long as the abbreviation is not ambiguous.

GETOPT_ALLOW_ALTERNATIVE - Allow long options to start with a single `-'. See (getopt -a).

GETOPT_POSIXLY_CORRECT - If the is set, all remaining parameters are interpreted as non-option parameters as soon as the first non-option parameter is found.

AUTHOR

Authors and contributors of the programs included in the libshell package are listed in the COPYING file.

BUGS

Report bugs to the authors.