Shell Programming and Scripting

/script$cat test.ksh
#!/bin/ksh
while getopts :f: arg
do
        case $arg in
                f) echo file is : $OPTARG
                        echo $OPTARG;;
                \?) echo "error";;
        esac
done

/script$./test.ksh -f abc
file is : abc
abc

/script$./test.ksh
/script$

#!/bin/ksh
while getopts ":f:" arg
do
        case $arg in
                f) echo file is : $OPTARG
                        echo $OPTARG;;
                \?) echo "error";;
                :) echo "Option -$OPTARG requires an argument."
                exit 1
        esac
done

if [[ $OPTIND == 1 ]]
then
        echo "No options were passed"
fi

./test_try.ksh
No options were passed

./test_try.ksh -f chumma
file is : chumma

chumma

./test_try.ksh -f
Option -f requires an argument.

#!/bin/ksh
IAm=${0##*/}
file=
while getopts :f: arg
do
        case $arg in
	(f)	file="$OPTARG"
		printf 'Found -f option; setting file="%s"\n' "$file";;
	(\?)	printf 'Usage: %s -f file operand...\n' "$IAm" >&2
		exit 1;;
        esac
done
shift $((OPTIND - 1))
if [ "$file" = "" ]
then	printf '%s: No "-f file" option found.\n' "$IAm" >&2
	exit 2
else	printf 'Last "-f file" option set file to "%s"\n' "$file"
fi
printf 'Operands remaining after option parsing:\n'
printf '\t"%s"\n' "$@"