clap4shell: standalone clap wrapper for shell scripts

clap4shell is a replacement for getopt based on clap.

clap4shell takes option descriptors as a YAML document from stdin, then prints the parsed result in newline-delimited key=value format which can be eval'd. See example.sh for concrete usage.

Installation

sh nix profile install github:fumieval/clap4shell

Usage

Configurations look like

```yaml name: example bin_name: $0 version: "1.0" about: sample text author: Fumiaki Kinoshita fumiexcel@gmail.com

Flags take no arguments.

Number of occurences will be reported (e.g. verbose=1)

flags: verbose: help: verbose output short: v long: verbose

Options arguments are collected as newline-separated list of values.

opts: # usage syntax is also supported # cf. https://docs.rs/clap/2.33.0/clap/struct.Arg.html#syntax host: -h --host 'host name' mode: long: mode help: option with a certain set of possible values possible_values: [ herbivore, carnivore, omnivore ]

Positional arguments

args: - name: cmd help: command required: true - name: arg help: command arguments multiple: true subcommands: ls: #The name will be assigned to $subcommand about: Display a list of entities args: - name: name multiple: true ```

The typical usage is to embed option definitions in a shell heredoc, pass all arguments to clap4shell and eval its output:

bash eval "$(clap4shell parse "$@" <<EOT ... EOT )"

Completion

clap4shell-completion <shell> -o <path> subcommand generates an autocompletion script and writes the script to path.

sh clap4shell clap4shell-completion bash -o ./bash-completion.sh < definition.yaml

Note that clap does not support completion for subcommands yet (clap panics for some reason)

Notes

I intentionally avoided using clap::App::from_yaml because the redundancy of the YAML representation and difficulty of debugging panics. The YAML interface is being deprecated: https://github.com/clap-rs/clap/issues/3087