Argc

Easily create a feature-rich command-line application 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] [value notation] [help string]

Define a positional argument.

# @arg arg1            A positional argument
# @arg arg2!           A required positional argument
# @arg arg3 <PATH>     A positional argument with value notation
# @arg arg4*           A positional argument support multiple values
# @arg arg5+           A required positional argument support multiple values
# @arg arg6=a          A positional argument with default value
# @arg arg7=`_fn`      A positional argument with default value from fn
# @arg arg8[a|b]       A positional argument with choices
# @arg arg9[`_fn`]     A positional argument with choices from fn
# @arg arg10[=a|b]     A positional argument with choices and default value
# @arg arg11![a|b]     A required positional argument with choices
# @arg arg12![`_fn`]   A required positional argument with choices from fn

@option

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

Define a option.

# @option    --opt1                 A option
# @option -a --opt2                 A option with short alias
# @option    --opt3 <PATH>          A option with value 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=`_fn`           A option with default value from fn
# @option    --opt9[a|b]            A option with choices
# @option    --opt10[`_fn`]         A option with choices from fn
# @option    --opt11[=a|b]          A option with choices and default value
# @option    --opt12![a|b]          A required option with choices
# @option    --opt13![`_fn`]        A required option with choices from fn
# @option -b --opt14 <PATH>         A option with short alias and value 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
# @flag  -f --flag3*      A flag can occure multiple times

@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 <nobody@example.com>

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

test.sh 2.17.1
nobody <nobody@example.com>
A demo cli

USAGE: test.sh <COMMAND>

COMMANDS:
  test  Run test

Value Notation

Value notation is used to describe value type of options and positional parameters.

# @option --target <FILE>
# @arg target <FILE>

Here are some value notation that will affect the shell completion.

• <FILE>: complete files in current directory
• <DIR>: complete directories in current directory
• <PATH>: complete files and directories in current directory

Shell Completion

completion scripts are available for bash/zsh/fish/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.