petereon / argyml

argyml is a command line tool that converts CLI arguments, options and flags into a YAML for downstream parsing

Introduction

argyml is a command line tool that converts CLI arguments, options and flags into a YAML for downstream parsing

Motivation

While there are spectacularly powerful CLI tools and shell-scripts, CLI parsing in shell itself remains a manual and error prone process. argyml aims to solve this by operating in tandem with yq to allow for more structured CLI argument parsing.

Example

get_host () {
    args=$(argyml $@)
    host=$(echo $args | yq eval '.[] | select(.key == "*host*") | .value' )
    echo $host
}

$ get_host --host 127.0.0.1
127.0.0.1

Usage

Usage of argyml is really easy, you pass it command-line arguments, options and flags:

argyml some arguments --host 127.0.0.1 -i --another-flag

and receive YAML in standard output:

- type: arg
  value: some
- type: arg
  value: arguments
- key: --host
  type: option
  value: 127.0.0.1
- key: -i
  type: flag
- key: --another-flag
  type: flag

Limitations

argyml parses the arguments on naive basis. Implications are the following:

• it cannot be provided with any sort of schema for options, flags and arguments or their types ¹

• arguments cannot follow flags, otherwise they will be interpreted as options

Roadmap

• Refactor
• Option to directly generate a bash associative array?
• Maybe figure out a way to provide schema for options, flags and arguments?

Footnotes

1. For type casting you should rely on downstream. ↩