3 ms·

As a final addendum, case clauses of options that take arguments like -a/--arg should not be terminated with `;;&`, but rather with `;;`.

by jolmg 6y ago

Spivak 6y ago
This is awesome! Thank you for being a total bash nerd.
- jolmg 6y ago
  There's still one problem. To exemplify it, if you call with `-av`, it'll process the `v` as the option `-v` instead of the option value to `-a`. If you only have one possible option that takes a value, this can be fixed by putting its case clause before all others. If you have more, then that'll require things to get a little more complicated: -d*|-[!-]*d*|--debug) if [[ ! "$finished_case" && ("$1" = --debug || "$1" =~ '^[^ad]*d') ]]; then debug=true fi ;;& -a*|-[!-]*a*|--arg) if [[ ! "$finished_case" && ("$1" = --arg || "$1" =~ '^[^a]*a') ]]; then if [[ "$1" != --arg ]]; then value="${1#*a}" fi if [[ ! "$value" ]]; then value="$2" shift fi finished_case=true fi ;;& ... esac shift finished_case= done All case-clauses would need to use `;;&` by the way, including `-v` and `-h`. The regex is generally: "^[^${all_options_with_values}${current_option}]*${current_option}" Another problem is that option and argument non-recognition would not work as previously layed out. You can include short options that aren't recognized, and they'll be ignored instead of raising errors. For positional arguments, one would need a condition to check for options, since using `;;&` for everything means that everything would land to *) Maybe those are the last issues, but this is already out of hand for otherwise small and simple shell scripts. All these complications arise from trying to support the sticking together of short options and their possible values. Processing arguments in a case loop is much, much simpler if we avoid supporting those 2 features.

As a final addendum, case clauses of options that take arguments like -a/--arg should not be terminated with `;;&`, but rather with `;;`.

by jolmg 6y ago

As a final addendum, case clauses of options that take arguments like -a/--arg should not be terminated with `;;&`, but rather with `;;`.

Spivak 6y ago

This is awesome! Thank you for being a total bash nerd.

jolmg 6y ago
There's still one problem. To exemplify it, if you call with `-av`, it'll process the `v` as the option `-v` instead of the option value to `-a`. If you only have one possible option that takes a value, this can be fixed by putting its case clause before all others. If you have more, then that'll require things to get a little more complicated: -d*|-[!-]*d*|--debug) if [[ ! "$finished_case" && ("$1" = --debug || "$1" =~ '^[^ad]*d') ]]; then debug=true fi ;;& -a*|-[!-]*a*|--arg) if [[ ! "$finished_case" && ("$1" = --arg || "$1" =~ '^[^a]*a') ]]; then if [[ "$1" != --arg ]]; then value="${1#*a}" fi if [[ ! "$value" ]]; then value="$2" shift fi finished_case=true fi ;;& ... esac shift finished_case= done All case-clauses would need to use `;;&` by the way, including `-v` and `-h`. The regex is generally: "^[^${all_options_with_values}${current_option}]*${current_option}" Another problem is that option and argument non-recognition would not work as previously layed out. You can include short options that aren't recognized, and they'll be ignored instead of raising errors. For positional arguments, one would need a condition to check for options, since using `;;&` for everything means that everything would land to *) Maybe those are the last issues, but this is already out of hand for otherwise small and simple shell scripts. All these complications arise from trying to support the sticking together of short options and their possible values. Processing arguments in a case loop is much, much simpler if we avoid supporting those 2 features.