JAVASCRIPT js-yaml.js

#!/usr/bin/env node

'use strict'

const fs = require('fs')
const argparse = require('argparse')
const yaml = require('..')

/// /////////////////////////////////////////////////////////////////////////////

const cli = new argparse.ArgumentParser({
  prog: 'js-yaml',
  add_help: true
})

cli.add_argument('-v', '--version', {
  action: 'version',
  version: require('../package.json').version
})

cli.add_argument('-c', '--compact', {
  help: 'Display errors in compact mode',
  action: 'store_true'
})

// deprecated (not needed after we removed output colors)
// option suppressed, but not completely removed for compatibility
cli.add_argument('-j', '--to-json', {
  help: argparse.SUPPRESS,
  dest: 'json',
  action: 'store_true'
})

cli.add_argument('-t', '--trace', {
  help: 'Show stack trace on error',
  action: 'store_true'
})

cli.add_argument('file', {
  help: 'File to read, utf-8 encoded without BOM',
  nargs: '?',
  default: '-'
})

/// /////////////////////////////////////////////////////////////////////////////

const options = cli.parse_args()

/// /////////////////////////////////////////////////////////////////////////////

function readFile (filename, encoding, callback) {
  if (options.file === '-') {
    // read from stdin

    const chunks = []

    process.stdin.on('data', function (chunk) {
      chunks.push(chunk)
    })

    process.stdin.on('end', function () {
      return callback(null, Buffer.concat(chunks).toString(encoding))
    })
  } else {
    fs.readFile(filename, encoding, callback)
  }
}

readFile(options.file, 'utf8', function (error, input) {
  let output
  let isYaml

  if (error) {
    if (error.code === 'ENOENT') {
      console.error('File not found: ' + options.file)
      process.exit(2)
    }

    console.error(
      (options.trace && error.stack) ||
      error.message ||
      String(error))

    process.exit(1)
  }

  try {
    output = JSON.parse(input)
    isYaml = false
  } catch (err) {
    if (err instanceof SyntaxError) {
      try {
        output = []
        yaml.loadAll(input, function (doc) { output.push(doc) }, {})
        isYaml = true

        if (output.length === 0) output = null
        else if (output.length === 1) output = output[0]
      } catch (e) {
        if (options.trace && err.stack) console.error(e.stack)
        else console.error(e.toString(options.compact))

        process.exit(1)
      }
    } else {
      console.error(
        (options.trace && err.stack) ||
        err.message ||
        String(err))

      process.exit(1)
    }
  }

  if (isYaml) console.log(JSON.stringify(output, null, '  '))
  else console.log(yaml.dump(output))
})