https://github.com/fumieval/clap4shell

Standalone wrapper of clap for shell scripts
https://github.com/fumieval/clap4shell

options-parsing rust shell-script

Last synced: about 2 months ago
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Standalone wrapper of clap for shell scripts

• Host: GitHub
• URL: https://github.com/fumieval/clap4shell
• Owner: fumieval
• Created: 2020-03-15T02:25:59.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2024-01-17T07:56:18.000Z (11 months ago)
• Last Synced: 2024-10-29T22:34:15.326Z (about 2 months ago)
• Topics: options-parsing, rust, shell-script
• Language: Rust
• Homepage:
• Size: 74.2 KB
• Stars: 33
• Watchers: 3
• Forks: 2
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
clap4shell: standalone clap wrapper for shell scripts

----

[![clap4shell at crates.io](https://img.shields.io/crates/v/clap4shell.svg)](https://crates.io/crates/clap4shell)

`clap4shell` is a replacement for `getopt` based on [clap](https://github.com/clap-rs/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: $(basename $0)

version: "0.0"

about: sample text

author: Fumiaki Kinoshita 

args:

  - verbose:

      help: verbose output

      short: v

      long: verbose

  - host:

      takes_value: true

      long: host

      value_name: 

      help: 'host name'

  - mode:

      long: mode

      help: option with a certain set of possible values

      possible_values: [ herbivore, carnivore, omnivore ]

  - cmd:

      help: command

  - arg:

      help: command arguments

      multiple_values: true

subcommands:

  - ls:

      about: Display a list of entities

      args:

        - entity:

            multiple_values: true

```

The schema is based on [clap_serde](https://docs.rs/clap-serde/latest/clap_serde/).

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

```bash

eval "$(clap4shell "$@" < -o ` subcommand generates an autocompletion script for `` and writes the script to `path`.

```sh

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

```

When "-o" is omitted, it prints an echo command that prints the script, followed by `exit 0`. Therefore this feature can be used transparently even if the output of `clap4shell` is passed to `eval`.

```

./foo.sh clap4shell-completion > ~/.zsh/_foo.sh

```

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