bash getopts with multiple and mandatory options

Ramesh Samane picture Ramesh Samane · Jul 1, 2012 · Viewed 85.8k times · Source

Is it possible to use getopts to process multiple options together? For example, myscript -iR or myscript -irv.

Also, I have a situation where based on a condition script would need mandatory option. For example, if argument to script is a directory, I will need to specify -R or -r option along with any other options (myscript -iR mydir or myscript -ir mydir or myscript -i -r mydir or myscript -i -R mydir), in case of file only -i is sufficient (myscript -i myfile).

I tried to search but didn't get any answers.

Answer

Dennis Williamson picture Dennis Williamson · Jul 1, 2012

You can concatenate the options you provide and getopts will separate them. In your case statement you will handle each option individually.

You can set a flag when options are seen and check to make sure mandatory "options" (!) are present after the getopts loop has completed.

Here is an example:

#!/bin/bash
rflag=false
small_r=false
big_r=false

usage () { echo "How to use"; }

options=':ij:rRvh'
while getopts $options option
do
    case "$option" in
        i  ) i_func;;
        j  ) j_arg=$OPTARG;;
        r  ) rflag=true; small_r=true;;
        R  ) rflag=true; big_r=true;;
        v  ) v_func; other_func;;
        h  ) usage; exit;;
        \? ) echo "Unknown option: -$OPTARG" >&2; exit 1;;
        :  ) echo "Missing option argument for -$OPTARG" >&2; exit 1;;
        *  ) echo "Unimplemented option: -$OPTARG" >&2; exit 1;;
    esac
done

if ((OPTIND == 1))
then
    echo "No options specified"
fi

shift $((OPTIND - 1))

if (($# == 0))
then
    echo "No positional arguments specified"
fi

if ! $rflag && [[ -d $1 ]]
then
    echo "-r or -R must be included when a directory is specified" >&2
    exit 1
fi

This represents a complete reference implementation of a getopts function, but is only a sketch of a larger script.