I have a file, a script which tells the computer to take some action. Call that file1. I don't want to change the name of file1 so it can't be called, as this is going to cause some kind of error.
What I want to know is what file calls file1. Then in file2, the calling file, I can comment out the call to file 1, and hopefully this will not cause an error condition.
The reason for this is that there are two conflicting actions, one in file1, one in file3, which is also called by something. I want to only call file 3, for the moment. If that doesn't solve the problem, I will go back and enable the call to file1, and disable the call to file3, and see if that works. (Probably the calls to file1 and file3 are in different scripts, not both in file2.) I'm trying to fix a bug I reported in Debian that does not seem to have any interest "upstream."

You can use ps -ef
Look for the PPID (Parent Process ID), this is the PID (Process id) of the calling command.

Hope this helps you

One more solution is - instead of commenting call to file1, just add return from the first line of its execution in file1. So even though file1 is called control returns back immediately without doing anything in file1.