Argc

Easily parse command line arguments in bash.

Install

With cargo

cargo install argc

Binaries on macOS, Linux, Windows

Download from Github Releases, unzip and add argc to your $PATH.

GitHub Actions

extractions/setup-crate can be used to install just in a GitHub Actions workflow.

- uses: extractions/setup-crate@v1
  with:
    owner: sigoden
    name: argc

Usage

To write a command-line program with argc, we only need to do two things:

1. Describe options, flags, positional parameters and subcommands in comments.
2. Insert eval $(argc "$0" "$@") into script to let argc to parse command line arguments.

Write example.sh

# @flag   --foo   A flag
# @option --bar   A option
# @option --baz*  A option with multiple values 

eval $(argc "$0" "$@")
echo foo: $argc_foo
echo bar: $argc_bar
echo baz: ${argc_baz[@]}

Run ./example.sh --foo --bar=value --baz a b c, you can see argc successfully parses arguments and generate variables with argc_ prefix.

foo: 1
bar: value
baz: a b c

Run example.sh -h, argc wll print help information for you.

USAGE: example.sh [OPTIONS]

OPTIONS:
      --foo             A flag
      --bar <BAR>       A option
      --baz [<BAZ>...]  A option with multiple values
  -h, --help            Print help information

Comment Tags

argc parses cli definition from comment tags.

@cmd

@cmd [string]

Define a subcommand

# @cmd Upload a file
upload() {
  echo Run upload
}

# @cmd Download a file
download() {
  echo Run download
}

USAGE: test.sh <COMMAND>

COMMANDS:
  upload    Upload a file
  download  Download a file

@arg

@arg <name>[modifier] [help string]

Define a positional argument.

# @arg arg1            A positional argument
# @arg arg2!           A required positional argument
# @arg arg3*           A positional argument support multiple values
# @arg arg4+           A required positional argument support multiple values
# @arg arg5=a          A positional argument with default value
# @arg arg6[a|b]       A positional argument with choices
# @arg arg7[=a|b]      A positional argument with choices and default value
# @arg arg8![a|b]      A required positional argument with choices

@option

@option [short] <long>[modifier] [notation] [help string]

Define a option.

# @option    --opt1                 A option
# @option -a --opt2                 A option with short alias
# @option    --opt3 <PATH>          A option with notation
# @option    --opt4!                A required option
# @option    --opt5*                A option with multiple values
# @option    --opt6+                A required option with multiple values
# @option    --opt7=a               A option with default value
# @option    --opt8[a|b]            A option with choices
# @option    --opt9[=a|b]           A option with choices and default value
# @option    --opt10![a|b]          A required option with choices
# @option -b --opt11 <PATH>         A option with short alias and notation

@flag

@flag [short] <long> [help string]

Define a flag. A flag is an option of boolean type, and is always false by default (e.g. --verbose, --quiet, --all, --long, etc).

# @flag     --flag1       A flag
# @flag  -f --flag2       A flag with short alias

@alias

@alias <name...>

Add aliases for subcommand.

# @cmd Run tests
# @alias t,tst
test() {
  echo Run test
}

USAGE: test.sh <COMMAND>

COMMANDS:
  test  Run tests [aliases: t, tst]

@help

@help string

Enable help subcommand.

# @help Show help

# @cmd Run test
test() {
  echo Run test
}

USAGE: test.sh <COMMAND>

COMMANDS:
  help  Show help
  foo   Run test

Meta

• @describe: Sets the cli’s description.
• @version: Sets cli's version.
• @author: Sets cli's author.

# @describe A demo cli
# @version 2.17.1 
# @author nobody <[email protected]>

# @cmd Run test
test() {
  echo Run test
}

test.sh 2.17.1
nobody <[email protected]>
A demo cli

USAGE: test.sh <COMMAND>

COMMANDS:
  test  Run test

Shell Completion

completion scripts are available for bash/zsh/powershell.

All argc scripts share the same completion function. To add completion to a argc script, simply add the script name to $ARGC_SCRIPTS.

License

Copyright (c) 2022 argc-developers.

argc is made available under the terms of either the MIT License or the Apache License 2.0, at your option.

See the LICENSE-APACHE and LICENSE-MIT files for license details.