Potential Typo on command.js

[samypr100]

On line 227 with the latest commit being d8e8d84
There's might be a typo.. and it's throwing a lot when we blast it with a lot of images with potential errors in that line. I couldn't find any documentation to stdin.once in any of the docs. It's saying:

"TypeError: Cannot read property 'once' of undefined"

Hence, instead of:

proc.stdin.once('error', cb);

Shouldn't it be (or something else, or should we do check if the stdin even exists):

proc.stdin.on('error', cb);

I'm using NodeJS LTS.

[samypr100]

Nevermind, figured out what once is.
The issue I was having was spawn EGAIN after the call stack exceeded due to the amount of files and the processes required to be spawn. After it hits the limit, spawn doesn't work well in NodeJS, at first it starts by being set to undefined and later starts throwing EGAIN spawn errors.
Issue #42 comments at the end helped a great deal.
I ended up using AsyncJS limit iterator in order to avoid going past the limits.
I wonder if there's a way to properly catch this error though.