CODEWITHSUNDEEP
node.js
ngmaloney
ngmaloney

Reputation: 65

Retrieving results of node.js child_process

I'm having trouble wrapping my head around the asynchronous nature of node.js. Lets suppose I wanted a route that executed an 'ls' command and returned the results (as a string) to browser. How would would one go about this using child_process.exec? Below is incorrect, but along the lines of what I'm struggling with:

function dir_list() {
  var sys = require('sys');
  var exec = require('child_process').exec
  child = exec('ls -la', function(error, stdout, stderr) {
    //I would like to return stdout but can't figure out how
    return stdout;
  });
  return child;
}

app.get('/', function(req, res){
  res.render('index', {
  title: 'MyPage',
  subtitle: 'Below is a directory listing',
  results: dir_list()
});

This isn't the entire code of my app.js but essentially i'm looking for help on getting dir_list() to set the results variable as the output of "ls -la".

Upvotes: 1

Views: 5294

Answers (1)

Andrey Sidorov
Andrey Sidorov

Reputation: 25466

pass callback to your dir_list and call it with ls -la result

function dir_list(cb) {
  var sys = require('sys');
  var exec = require('child_process').exec
  child = exec('ls -la', function(error, stdout, stderr) {
    //I would like to return stdout but can't figure out how
    cb(stdout);
  });
}

app.get('/', function(req, res){
  dir_list(function(dir_list_output) {
      res.render('index', {
      title: 'MyPage',
      subtitle: 'Below is a directory listing',
      results: dir_list_output});
  });
});

Upvotes: 11

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