generateコマンドは読み取り可能なストリームを返すため、便利な操作を実行するには書き込み可能なストリームにパイプする必要があります。

パイプからファイルへ

// the filed module makes simplifies working with the filesystem
var filed = require('filed')
var path = require('path')
var spawn = require('spawn')
var outputPath = path.join(__dirname, 'out.txt')

// filed is smart enough to create a writable stream that we can pipe to
var writableStream = filed(outputPath)

var cmd = path.join(__dirname, 'my_script.bash')
var args = [] // you can option pass arguments to your spawned process
var child = spawn(cmd, args)

// child.stdout and child.stderr are both streams so they will emit data events
// streams can be piped to other streams
child.stdout.pipe(writableStream)
child.stderr.pipe(writableStream)

child.on('error', function (err) {
  console.log('an error occurred')
  console.dir(err)
})

// code will be the exit code of your spawned process. 0 on success, a positive integer on error
child.on('close', function (code) {
  if (code !== 0) {
  console.dir('spawned process exited with error code', code)
    return
  }
  console.dir('spawned process completed correctly at wrote to file at path', outputPath)
})

上記の例を実行するには、アーカイブモジュールをインストールする必要があります。

npm install filed

stdoutとstderrによるパイプ

process.stdoutとprocess.stderrはどちらも書き込み可能なストリームであるため、生成されたコマンドの出力をコンソールに直接パイプすることもできます。

var path = require('path')
var spawn = require('spawn')
var cmd = path.join(__dirname, 'my_script.bash')
var args = [] // you can option pass arguments to your spawned process
var child = spawn(cmd, args)

// child is a stream so it will emit events
child.stderr.pipe(process.stderr)
child.stdout.pipe(process.stderr)

child.on('error', function (err) {
  console.log('an error occurred')
  console.dir(err)
})

// code will be the exit code of your spawned process. 0 on success, a positive integer on error
child.on('close', function (code) {
  if (code !== 0) {
  console.dir('spawned process exited with error code', code)
    return
  }
  console.dir('spawned process completed correctly at wrote to file at path', outputPath)
})