Bash script to run a clamscan on Ubuntu- how to use return values properly?

Question

I'm trying to put together a simple script that will scan my home directory with clamscan and give me a warning if any viruses were found. What I have so far is:

#! /usr/bin/env bash

clamscan -l ~/.ClamScan/$(date +"%a%b%d") -ir /home
RETVAL=$?
[ $RETVAL -eq 0 ] && notify-send 'clamscan finished. No viruses found'
[ $RETVAL -eq 1 ] && notify-send 'clamscan found a virus' && touch ~/Desktop/VirusFound
[ $RETVAL -eq 2 ] && notify-send 'clamscan encountered errors. Check the logs' && touch ~/Desktop/ClamscanError

find ~/.ClamScan/* -mtime +7 -exec rm {} \;

However, I'm unsure about a couple of things:

I'm always wary of using rm- as far as I can tell, the find command I've got should be deleting any log files that are more than a week old.

I'm also not entirely sure how the return value testing works- I've got a manual that briefly covers bash, which says that the meaning of $? is "match one character", and I'm not entirely sure how that grabs the return value. Should I be using -eq or = for testing the return value? From what I can tell -eq tests strings and = tests numerals, but I'm not sure what the type of the return value is.

Answer 1

If you'd like more info on bash you can type man bash to read the online manual.

-eq is the correct operator for testing if numbers are equal.

? (without the dollar sign) "Matches a single character" when doing filename pattern matching. $? is a Special Parameter that "Expands to the status of the most recently executed foreground pipeline" (for your purposes "foreground pipeline" just means command)