node.js - How to use mogrify command with graphicsmagick and node js

Question

I checked the graphicsmagick documentation. However there is no information on using mogrify command with Graphicsmagick.

http://aheckmann.github.io/gm/docs.html

Currently the code mentioned below creates multiples copies of the file and doesn't rename them as per the original file.

gm('*.png').crop(985, 631, 461, 144).write('*.png', function (err) {
  if (!err) console.log('done');
});