What is "* * * * *" command anyway?
I was wanting to do something entirely irrelevant: Running a cron job manually and immediately
The answer suggests this:
# Create a environment file with a temporary cron entry * * * * * /usr/bin/env > /home/username/cron-env
and I took it literally:
~$ * * * * * /usr/bin/env certbot-auto: command not found
Hmm… WHAT? What is this command? What is
certbot-auto anyway? How are these related? C’mon!
I will skip all the dead ends I visited here… the pain & pleasure are always in the process. Turns out, it has nothing to do with crontab, nor systemctl. It’s not linux, and it’s useless to search for 5 consequtive asterisks anyway
which * man *
It’s bash expansion.
* get expanded to a list of file names. One of the files in PWD is called
certbot-auto. But to run it, you have to do
./certbot-auto, hence command not found
I’m Happy now.