Bash subcommands with arguments - bash

Question

I have a script in bash as such:
#!/usr/bin/env bash
set -e
if [[ "$#" == 0 ]]; then
printhelp
exit 1
fi
# process options
while [[ "$1" != "" ]]; do
case "$1" in
-n | --name)
shift
_NAME="$1"
;;
-i | --id)
shift
_ID="$1"
;;
-h | --help)
printhelp
exit 1
;;
*)
printhelp
exit 1
;;
esac
shift
done
This works fine, but I want to add some "actions" that will take the above params. Eg. usage will be:
./run.sh create --name foo --id 1234
./run.sh delete --id 1234
I am not able to figure out the right syntax, and I am unable to phrase this requirement into appropriate words to be able to search.

Answer 1

For sub-command you can handle it this way:
function main(){
if (( ${#} == 0 )); then
main_help 0;
fi
case ${1} in
help | version | encrypt | decrypt )
$1 "${#:2}";
;;
* )
echo "unknown command: $1";
main_help 1;
exit 1;
;;
esac
}
main "$#";
Then wrap each sub-command is a function. And inside each function you will have isolated options and parsing it separately.
For example:
function decrypt(){
if [[ ${#} == 0 ]]; then
decrypt_help;
fi
local __filename='';
local __salt='';
local __anchor=false;
local error_message='';
while [ ${#} -gt 0 ]; do
error_message="Error: a value is needed for '$1'";
case $1 in
-f | --file )
__filename=${2:?$error_message}
shift 2;
;;
-s | --salt )
__salt=${2:?$error_message}
shift 2;
;;
-a | --anchor )
__anchor=${2:?$error_message}
shift 2;
;;
* )
echo "unknown option $1";
break;
;;
esac
done
echo filename: ${__filename:-empty};
echo salt: ${__salt:-empty};
echo anchor: $__anchor;
exit 0;
}
Here is a full version bash-CLI-template I have used in my projects
demo ;)

Answer 2

Sounds like you want something like:
create() {
# actiony stuff here
}
ACTION=$1 ; shift
# put all your argument parsing here
$ACTION # call
However, since different actions probably have different arguments, I'd probably do it differently...
create() {
# argument parsing for create
# then do your create stuff
}
ACTION=$1 ; shift
$ACTION "$#"
This will pass all your arguments to your subfunction, which can then parse its own arguments.