At work we commonly use "exit" as a method of telling the calling party the status of the exit. exit 0 is normal, exit -1 on an error. We have various other programs written in other languages that call perl scripts. If they get a negative value in the exit they know there was an issue with the script and report it in a log or something similar. The values are arbitrary, it all depends on what you expect to be an error free exit versus what you expect to indicate an error.