next.js/packages/next/bin/next-start

#!/usr/bin/env node

import { resolve } from 'path'
import parseArgs from 'minimist'
import startServer from '../server/lib/start-server'

const argv = parseArgs(process.argv.slice(2), {
  alias: {
    h: 'help',
    H: 'hostname',
    p: 'port'
  },
  boolean: ['h'],
  string: ['H'],
  default: { p: 3000 }
})

if (argv.hostname === '') {
  console.error(`> Provided hostname argument has no value`)
  process.exit(1)
}

if (argv.help) {
  console.log(`
    Description
      Starts the application in production mode.
      The application should be compiled with \`next build\` first.

    Usage
      $ next start <dir> -p <port>

    <dir> is the directory that contains the compiled dist folder
    created by running \`next build\`.
    If no directory is provided, the current directory will be assumed.
    You can set a custom dist folder in config https://github.com/zeit/next.js#custom-configuration

    Options
      --port, -p      A port number on which to start the application
      --hostname, -H  Hostname on which to start the application
      --help, -h      Displays this message
  `)
  process.exit(0)
}

const dir = resolve(argv._[0] || '.')

startServer({dir}, argv.port, argv.hostname)
  .then(() => {
    console.log(`> Ready on http://${argv.hostname ? argv.hostname : 'localhost'}:${argv.port}`)
  })
  .catch((err) => {
    console.error(err)
    process.exit(1)
  })