getopt-example.sh

#!/bin/sh
#
# Example showing use of getopt detection and use of GNU enhanced getopt
# to handle arguments containing whitespace.
#
# Written in 2004 by Hoylen Sue <hoylen@hoylen.com>
#
# To the extent possible under law, the author(s) have dedicated all copyright and
# related and neighboring rights to this software to the public domain worldwide.
# This software is distributed without any warranty.
#
# You should have received a copy of the CC0 Public Domain Dedication along with this software.
# If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.

PROG=`basename $0`
VERSION=0.1

# Remove this trap if you are doing your own error detection or don't care about errors
trap "echo $PROG: error encountered: aborted; exit 3" ERR

#----------------------------------------------------------------
# Process command line arguments

## Define options: trailing colon means has an argument (customize this: 1 of 3)

SHORT_OPTS=o:vh
LONG_OPTS=output:,verbose,version,help

SHORT_HELP="Usage: $PROG [options] arguments
Options:
  -o file  output file name
  -v       show extra information
  -h       show this help message"

LONG_HELP="Usage: $PROG [options] arguments
Options:
  -o | --output file  output file name
  -v | --verbose      show extra information
  -h | --help         show this help message
  --version           show version information"

# Detect if GNU Enhanced getopt is available

HAS_GNU_ENHANCED_GETOPT=
if getopt -T >/dev/null; then :
else
  if [ $? -eq 4 ]; then
    HAS_GNU_ENHANCED_GETOPT=yes
  fi
fi

# Run getopt (runs getopt first in `if` so `trap ERR` does not interfere)

if [ -n "$HAS_GNU_ENHANCED_GETOPT" ]; then
  # Use GNU enhanced getopt
  if ! getopt --name "$PROG" --long $LONG_OPTS --options $SHORT_OPTS -- "$@" >/dev/null; then
    echo "$PROG: usage error (use -h or --help for help)" >&2
    exit 2
  fi
  ARGS=`getopt --name "$PROG" --long $LONG_OPTS --options $SHORT_OPTS -- "$@"`
else
  # Use original getopt (no long option names, no whitespace, no sorting)
  if ! getopt $SHORT_OPTS "$@" >/dev/null; then
    echo "$PROG: usage error (use -h for help)" >&2
    exit 2
  fi    
  ARGS=`getopt $SHORT_OPTS "$@"`
fi
eval set -- $ARGS

## Process parsed options (customize this: 2 of 3)
 
while [ $# -gt 0 ]; do
    case "$1" in
        -o | --output)   OUTFILE="$2"; shift;;
        -v | --verbose)  VERBOSE=yes;;
        -h | --help)     if [ -n "$HAS_GNU_ENHANCED_GETOPT" ]
                         then echo "$LONG_HELP";
                         else echo "$SHORT_HELP";
                         fi;  exit 0;;
        --version)       echo "$PROG $VERSION"; exit 0;;
        --)              shift; break;; # end of options
    esac
    shift
done

## Process remaining arguments and use options (customize this: 3 of 3)

echo "$PROG: DEBUG: option VERBOSE: $VERBOSE"
echo "$PROG: DEBUG: option OUTFILE: $OUTFILE"

if [ $# -gt 0 ]; then
  for ARG in "$@"; do
    echo "$PROG: DEBUG: argument: $ARG"
  done
fi

#EOF