I use a PHP web app for my invoicing runs. Part of this involves running a command every night to generate new invoices. Usually this is not a big deal because most invoices are created manually anyway. But I’m starting to get more auto-generated invoices, so I decided to whack the generation command into the crontab.

I noticed pretty quick that it wasn’t running. Not happy! I know that often this results from a problem with the command being executed (execution permissions) or incorrect times in the crontab line. But what it also depends on, is the correctness of the file up to that line. If a line is incorrect, cron will fail on that line, and so you (may) notice that your command doesn’t run!

Just make sure that all lines in the crontab are correct. Also, Debian requires the user to be listed in field 6, so most of the time when people say “add this line to your crontab” it won’t work in Debian- you need to add the user after the run time.