Q:

Write to another already running process stdin from Node.js without starting from inside

I have a program that isn't started from inside Node.js, so I cannot use spawn'd stdin to write to. I have the PID of the process that is listening for stdin input, how can I write to it using my node code? 
I always see code examples using child_process module, and my use case is different.

A:

On Linux you should be able to write to '/proc/' + pid + '/fd/0'. However this isn't portable.

