Shell Programming and Scripting

#!/bin/bash
        lflag=
        iflag=
        while getopts 'l:i:' OPTION
        do
          case $OPTION in
          l)    lflag=1
                        lval="$OPTARG"
                        ;;
          i)    iflag=1
                        ival="$OPTARG"
                        ;;
          ?)    printf "Usage: %s: [-a] [-b value] args\n" $(basename $0) >&2
                        exit 2
                        ;;
          esac
        done
shift $(($OPTIND - 1))

#!/bin/bash -

# @(#) s1       Demonstrate getopts.

echo
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version =o $(_eat $0 $1)
set -o nounset
echo

U=./user1
echo " Contents of script $U:"
cat $U

echo
echo " For plain:"
$U

echo
echo " For illegal argument:"
$U -z

echo
echo " For missing option-arguments:"
$U -i
$U -l

echo
echo " For legitimate option arguments:"
$U -ix -l y -- file1 file2

exit 0

% ./s1

(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash 2.05b.0

 Contents of script ./user1:
#!/bin/bash
        lflag=
        iflag=
        while getopts 'l:i:' OPTION
        do
          case $OPTION in
          l)    lflag=1
                        lval="$OPTARG"
                        ;;
          i)    iflag=1
                        ival="$OPTARG"
                        ;;
          ?)    printf "Usage: %s: [-a] [-b value] args\n" $(basename $0) >&2
                        exit 2
                        ;;
          esac
        done
shift $(($OPTIND - 1))

echo
echo " iflag = $iflag, ival = $ival; lflag = $lflag, lval = $lval"

echo
echo " Remaining command line:"
echo $*

 For plain:

 iflag = , ival = ; lflag = , lval =

 Remaining command line:


 For illegal argument:
./user1: illegal option -- z
Usage: user1: [-a] [-b value] args

 For missing option-arguments:
./user1: option requires an argument -- i
Usage: user1: [-a] [-b value] args
./user1: option requires an argument -- l
Usage: user1: [-a] [-b value] args

 For legitimate option arguments:

 iflag = 1, ival = x; lflag = 1, lval = y

 Remaining command line:
file1 file2