abs-guide | Advanced Bash-Scripting Guide | Script Programming library

look i had the follow variables :

I am curious about how exactly dpkg -L package_name works.

Here is what man says:

I'm somewhat new to the world of Bash scripting, and am still attempting to understand what most would consider to be the basics. I found this helpful guide which I have been pulling most of my information from, and despite it referring to "advanced" it actually covers the basics very well for a newcomer like myself.

At this point, I have written a script that works how I want it to, however I guess I'm what some might consider to be code conscious. So while my script does indeed work, I don't think I'm utilizing Bash's if/then/else statements properly.

Here is the small script I've written that basically checks for usernames, and whether or not they exist, via an API query. It allows a user to define a list via ./script.sh list, or if they do not define a list it simply attempts all variations of letters ({a..z}):