Bash Shell Script – How to Terminate Running in Background

I often use bash shell scripts to run simple commands for many different files. For example, suppose that I have the following bash shell script, called script.sh, that runs the program/command foo on three text files "a.txt", "b.txt", "c.txt":

#!/bin/bash

for strname in "a" "b" "c"
do
foo $strname".txt"
done

Also, suppose that foo $strname".txt" is slow, so the execution of the script will take a long time (hours or days, for example). Because of this, I would like to use nohup so that the execution continues even if the terminal is closed or disconnected. I would also like the script to immediately go to the background, so I will use the & operator. Thus I will use the following command to call script.sh:

nohup bash script.sh &

This works fine for running the script in the background and without hangup, but now suppose that I would like to terminate the execution at some point for some reason. How can I do this?

The problem that I have encountered is that, by looking at top, I see only the foo corresponding to "a.txt". I can terminate that foo call, but then the foo corresponding to "b.txt" gets called and then I have to terminate that one as well, and so on. For tens or hundreds of text files specified in the for loop, it becomes a pain to terminate every foo, one by one! So somehow I need to instead terminate the shell script itself, not the particular calls issued from the shell script.

When I type the command

ps -u myusername

where myusername is my username, I get a list of processes that I'm running. But I see two different process IDs called bash. How do I know which of these processes, if any, corresponds to my original call nohup bash script.sh &?