'process.stdout cannot be closed': process.stdout should behave like a standard stream

[yinrong]

• Version: latest
• Platform: all
• Subsystem: node/lib/internal/process/stdio.js

sample code:

// hang process
setTimeout(function(){}, 9999999)
// in heavy development, there usually exists something that hangs the process.
// we use 'process.exit' to solve this quickly.

var stream = require('stream')
process.stdin
  .pipe(new stream.PassThrough()) // there can be a list of Transform
  .pipe(new stream.PassThrough()) // there can be a list of Transform
  .pipe(new stream.PassThrough()) // there can be a list of Transform
  .on('end', function() {
    // process.exit()
    // exit here will stop stdout from flushing
  })
  .pipe(process.stdout)
  .on('finish', function() {  // this event will not trigger
    process.exit()
  })

execution result: hangs forever

expect: process.stdout should behaves like a standard stream.

[bnoordhuis]

That behavior is intentional and fixes more issues than it introduces. Most programs fail very badly if stdio could be closed and in fact they did. That's why we made stdio permanent in v0.6.0.

I'll go ahead and close the issue.

[Judimax]

@bnoordhuis, is this functionality the same for stdin and stderr, how can I properly attach and deattach a Writable Stream to process.stdout out so I can get all my console output to a file

[sam-github]

In my opionion, node lacks process.stdio.reopen(), or something similar -- an equivalent to freopen(3).

[Judimax]

solution I implemented check if this works or its a safe solution
https://stackoverflow.com/questions/32719923/redirecting-stdout-to-file-nodejs/54407338#54407338

[0xkarambit]

I think that the fact that stdout doesn't emit the "finish" event should be mentioned in the nodejs
docs under the "a note of process io" section on the page about process
https://nodejs.org/api/process.html#process_a_note_on_process_i_o

[ronag]

It does emit the finish event, try:

const { stdout } = require('process');

process.stdout
  .on('finish', () => console.error('finish'))
  .end()

[0xkarambit]

Oh yes, it does sorry for that, I am just a beginner.