[SOLVED] bash getopts with multiple and mandatory options

bash getopts with multiple and mandatory options

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.

Solution

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:rRvhm'
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 -$OPTARG" >&2; exit 1;;
        *  ) echo "Unimplemented option: -$option" >&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.