javascript - Shell command execution -

i'm trying implement shell command execution found here: node.js shell command execution

so i'm trying second answer (by chris eineke) working. no output.

here try:

run_cmd = (cmd, args, done) ->     spawn = require('child_process').spawn     child = spawn(cmd, args)     result = { stdout: '' };     child.stdout.on \data ! (buffer) ->         result.stdout += buffer     child.stdout.on \end !-> done()     result  dir = run_cmd(     'ls', ['-a']     , !-> console.log('done')     )  console.log dir.stdout 

it compiles to:

  run_cmd = function(cmd, args, done){     var spawn, child, result;     spawn = require('child_process').spawn;     child = spawn(cmd, args);     result = {       stdout: ''     };     child.stdout.on('data', function(buffer){       result.stdout += buffer;     });     child.stdout.on('end', function(){       done();     });     return result;   };   dir = run_cmd('ls', ['-a'], function(){     console.log('done');   });   console.log(dir.stdout); 

but can't see ls results. mistake? or doing wrong?

you're not seeing results because run_cmd runs async , result empty when console.log dir.stdout ran. should rather pass results callback , logging there. here's working livescript version:

run_cmd = !(cmd, args, done) ->   spawn = require 'child_process' .spawn   child = spawn cmd, args   result = stdout: ''   child.stdout     ..on \data !(buffer) ->       result.stdout += buffer     ..on \end !->       done result  <-! run_cmd \ls <[ -a ]> console   ..log \done   ..log it.stdout 

here see multiple ls features used paren-free chaining (spawn line), braceless object definition (result line), cascades (the ..on , ..log lines), backcalls (<-!), word arrays (<[ array of words ]>) , implicit argument (it). more info on them, refer livescript documentation.