Bash getopts
Not to be confused with getopt, getopts is for dealing with command line variables that are more complex than just needing to grab the first or second variable.
I like to reuse code when I can or at least leave myself enough information to use it again. It had been a long time since I used getopts and I liked how flexible it is to use when dealing with a lot of command-line variables. I wrote the code for a work project and since the repo isn't public, I just wanted to capture a few key pieces. Obviously, the main one is that getopts doesn't deal with long options very well, but apparently getopt does, but is more complicated and less flexible. So here we are.
Example⚑
We start with a while loop to check each option as it is read. A : after the letter indicates that there is a required value that goes with that flag. Letters/options can be touching but a : at the beginning means to silence the warnings that are generated so you can use your own error checking. The options are pulled in and then you just step through them with a case statement.
while getopts "m:b:r:l:" OPTS; do
case $OPTS in
m)
if [ $OPTARG = "start" ]; then
STATUS="start"
elif [ $OPTARG = "stop" ]; then
STATUS="stop"
elif [ $OPTARG = "reload" ]; then
STATUS="reload"
elif [ $OPTARG = "status" ]; then
STATUS="status"
else
echo "No option picked"
fi
;;
b)
if [ $STATUS != "start" ]; then
echo "'start' required for this option"
exit 2
else
STATUS="start"
BSTATUS="1"
BRANCH="$OPTARG"
echo "Custom branch is: $BRANCH"
fi
;;
r)
if [ $STATUS != "start" ]; then
echo "'start' required for this option"
exit 2
else
STATUS="start"
CSTATUS="1"
CRULES="$OPTARG"
echo "Custom rules file: $CRULES"
fi
;;
l)
if [ $STATUS != "start" ]; then
echo "'start' required for this option"
exit 2
else
STATUS="start"
BLOCK="$OPTARG"
if [ $BLOCK = off ]; then
echo "Pass mode enabled"
else
BLOCK="on"
fi
fi
;;
*)
cmd_usage
break
;;
esac
done