How to make a script that drives in data from the source code?

Question

JavaScript

There is a site with a primitive captcha (4 digits, each of which has the same address like /images/captcha/ X .png from 0 to 9), what is the best way to make a script that would take X and insert it into the input field?

Answer 1

Get src images and parse until you get the desired result.

Answer 2

what is the best way to make a script that would take X and insert it into the input field?

It's best to just do it :)
Use Phantomjs, write a script for it and let it pull captchas, log in, etc.