Getops usage in UNIX

Shell Programming and Scripting
1

I have a case where the script has to run in two modes as options and based on the mode, script excepts optional and mandatory arguments.

script.sh -a  -f  <value1> -d <value2> -h <value3>
script.sh -b  -i <value4>

a and b are the modes of the script execution.
value2, value3 are optional.

I just know the basic usage of getopts. But can someone help me implementing the case in getops?

Thanks in advance!

2

Maybe should you explain us how you see your getopts stanza...
what have you done so far?

3

This is what i tried. Mainly I'm facing issue while applying mutually exclusive conditions of the options. Like either a or b should be passed, but not both and likewise optional arguments as well.

while getopts :abf:d:h:i: mode
do
        case $mode in
        a)adhoc=1;;
        b)batch=1;;
        f)fn=$OPTARG;;
        d)del=$OPTARG;;
        h)hd=$OPTARG;;
        i)id=$OPTARG;;
        *)echo "Invalid arg";;
esac done

if [[ ! -z $adhoc ]]
then
    echo "Adhoc processing"
    echo "fn: " $fn
    echo "del: " $del
    echo "hd: " $hd
fi

if [[ ! -z $batch ]]
then
    echo "Batch processing"
    echo "id: " $id
fi
4

Personally, I'd probably just do validation on all the arguments after you finish grabbing them with getopts:

So just add this after your existing getopts case (and prior to your other ifs):

if [[ $adhoc -eq 1 && $batch -eq 1 ]]
then
  echo "Cannot specify both adhoc and batch."
  exit 1
fi

(for example) ...

5

That covers the case where both of the exclusive options are present, but doesn't notice if neither -a nor -b was given. Perhaps adding:

adhoc=0
batch=0

before the getopts loop and:

if [ $((adhoc + batch)) -ne 1 ]
then    echo "Exactly one of -a and -b must be specified." >&2
        exit 1
fi

after the loop would be better.