docpars

An ultra-fast parser for declarative command-line options for your shell scripts.

It implements the Docopt syntax and is written in Rust.

Table of contents

• Usage
• Motivation
• Installation
  • Using Homebrew or Linuxbrew
  • Using cargo
  • Downloading pre-compiled binaries
  • Building from source
• Credits

Usage

If you run coffee make --dark for the following script... ```bash

!/usr/bin/env bash

? Coffee tool

?

? Usage:

? coffee make [--dark]

? coffee drink

This function could be included in a helper bash file

and imported by all your scripts

args::parse() { eval "$(/path/to/docpars -h "$(grep "^##?" "$0" | cut -c 5-)" : "$@")" }

args::parse "$@"

if $drink; then echo "Drinking coffee..." elif $make; then $dark && echo "Making dark coffee..." || echo "Making coffee..." fi ```

...then Making dark coffee... should be printed.

Motivation

The default implementation of docopt for shell scripts use Python under the hood. You may want to use docpars instead in the following scenarios

You want portability

This may be the case of CI/CD instances, minimal docker containers or environments where you may want to run some scripts but aren't equipped with your whole dev arsenal, such as Termux on Android or WSL on Windows.

You want extreme performance

Benchmarks show that docpars is up to 5.7 times faster than the Python equivalent.

This may not be noticible for most use-cases but it may make the difference if your script is called inside a for loop, for example.

Installation

Using Homebrew or Linuxbrew

sh brew install denisidoro/tools/docpars

Using cargo

bash cargo install docpars

Downloading pre-compiled binaries

You can download built binaries here.

They are available for OSX, Android and Linux with ARM and x86_64 variants.

Building from source

bash git clone https://github.com/denisidoro/docpars ~/.docpars cd ~/.docpars cargo install --path .

Credits

Most work was done in docopt.rs by BurntSushi, where the actual Docopt parsing is implemented.