Further Reading

• Bash Functions: https://linuxize.com/post/bash-functions/
• Returning Values from Bash Functions: https://www.linuxjournal.com/content/return-values-bash-functions
• Bash Function & How to Use It {Variables, Arguments, Return}: https://phoenixnap.com/kb/bash-function
• Writing shell scripts-Lesson 15: Errors and Signals and Traps: http://linuxcommand.org/lc3_wss0150.php
• (Note that the author of this tutorial uses all upper-case letters for the names of scripting variables, which is something that I don’t advocate. Other than that, it’s a good tutorial.)
• Advance Bash Script Guide: https://tldp.org/LDP/abs/html/abs-guide.html#FUNCTIONS