GETOPTS case with no optional arguments - bash

Question

Hello I'm trying to find a way how to make getopts work with non of expected optional arguments
I have a script with optional arguments
script.sh [-a] [-b] [-c | -d] file
I have it working with -a..-d like this
while geopts abc:abd opt
do
case $opt in
a) do this ;;
b) do this ;;
...
.. etc
I want to make it so it can work without those arguments, so I can run it like this
script.sh file
Is there a way to make a new case option or do I need to do it other way, thanks for all help, im a beginner in bash.

Answer 1

I've done this kind of thing before:
declare -A have=([a]=false [b]=false [c]=false [d]=false)
while geopts :abcd opt; do
case $opt in
a) have[a]=true ;;
b) have[b]=true ;;
c) have[c]=true ;;
d) have[d]=true ;;
?) echo "illegal option: -$OPTARG"; exit 1;;
esac
done
shift $((OPTIND-1))
if ${have[c]} && ${have[d]}; then
echo "cannot give both -c and -d"
exit 1
fi
${have[a]} && do_a_stuff
${have[b]} && do_b_stuff
...
That case statement is a pretty egregious bit of cut'n'paste programming: tightening it up:
while geopts :abcd opt; do
case $opt in
a|b|c|d) have[$opt]=true ;;
?) echo "illegal option: -$OPTARG"; exit 1;;
esac
done

Answer 2

I have the following test script:
#! /bin/bash
USAGE="test.sh [-a] [-b] [-c | -d ]"
while getopts :abcd option
do
case $option in
a) OPT_A=1;;
b) OPT_B=1;;
c) OPT_C=1;;
d) OPT_D=1;;
*)
echo "$OPTARG is not a valid option."
echo "$USAGE"
exit 2;;
esac
done
shift $((OPTIND-1))
if [[ $OPT_C && $OPT_D ]]
then
echo "That's a no-no using options c and d together"
echo "$USAGE"
exit 2
fi
echo "The following options were set"
[[ $OPT_A ]] && echo " Option A was set"
[[ $OPT_B ]] && echo " Option B was set"
[[ $OPT_C ]] && echo " Option C was set"
[[ $OPT_D ]] && echo " Option D was set"
echo "And the file name is $1"
It will show you what options were set (and which ones weren't). It tests to make sure that -c and -d aren't used together.
Not 100% sure what you're asking for. But, you can see that instead of saying do this in my case statement, I'm merely setting variables that show what options were or weren't selected. That in itself my solve your problem.