parsec

CLI parser

Install | Synopsis | Usage | Example | Hacking | About

Install

npm install parsec

Synopsis

Parsec is a CLI parser in 50 LOC.

// node ./index.js -abc --secret=42
parse()

{
  "a": true,
  "b": true,
  "c": true,
  "secret": 42
}

Customize:

// node ./index.js -s42
parse("secret", ["verbose", "V", { default: true }])

{
  "s": 42,
  "secret": 42,
  "V": true,
  "verbose": true
}

Features

• Simple
• Based in the UNIX Utility Conventions
• Custom aliases

• Default shorthands

• Default values / types
• Handle --no-* options
• Handle unknown options

Usage

Parse process.argv by default.

import parse from "parsec"
parse(alias1, alias2, ...)

• Custom aliases

  // node ./index.js --bar
  parse(["foo", "bar", "baz"])
  

  {
    "foo": true,
    "bar": true,
    "baz": true
  }
  

• Example aliases

  "foo" // → ["f", "foo"]
  ["F", "f", "foo"]
  ["foo", { default: "./" }]
  ["baz", { default: true }]
  

• Default shorthands

  // node ./index.js -fb
  parse("foo", "bar")
  

  {
    "f": true,
    "foo": true,
    "b": true,
    "bar": true,
  }
  

• Default values and types

  // node ./index.js --file
  parse(["f", "file", { default: "." }])
  

  {
    "f": ".",
    "file": "."
  }
  

• Handle --no-flags

  // node ./index.js --no-foo --no-bar=baz
  parse()
  

  {
    "foo": false,
    "no-bar": "baz"
  }
  

• Handle unknown options

  // node ./index.js --bar
  parse("foo", (option) => {
    throw new RangeError(`unknown option ${option}`) // bar
  })
  

• Bare operands and arguments after -- are added to ._. To override:

  parse(["_", "alias"])
  

• Bind parse to a different source of arguments:

  parse.call(["--foo", "--bar"], [alias1, alias2, ...])
  

Example

// ./node index.js -f bar -bp
parse()

{
  "f": "bar",
  "b": true,
  "p": "./"
}

with custom aliases:

parse("foo", "bar", ["path", { default: "./" }])

{
  "f": "bar",
  "foo": "bar",
  "b": true,
  "bar": true,
  "p": "./",
  "path": "./"
}

About

I also found the following projects useful and inspiring while writing Parsec:

• minimist
• nopt
• commander
• yargs

Hacking

git clone https://github.com/bucaran/parsec
cd parsec
npm run setup

License

MIT © Jorge Bucaran et al :heart: