crontab PATH and USER

Question

I am new to scheduling tasks with cron and crontab. I am trying to schedule execution of a task as if I had logged on, opened a terminal, and executed it myself.

However, I scheduled a task to help me observe what $USER and $PATH a scheduled task is executing with, and this is what I found:

$ crontab -l 41 11 * * * echo "USER: $USER" > ~/Desktop/cron_env.log; echo "PATH: $PATH" >> ~/Desktop/cron_env.log $ cat ~/Desktop/cron_env.log USER: PATH: /usr/bin:/bin 

It appears as though $USER is not set, and $PATH is something very basic and/or default. On the contrary, this is what I see when I open a terminal (logged in) and echo this same information:

USER: aschirma PATH: /usr/lib/jvm/java-6-sun/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/pkg/icetools/bin:/pkg/hwtools/bin:/pkg/netscape/bin:/pkg/gnu/bin 

What do I need to do to make my crontab tasks run the way I want?

Answer 1

According to "man 5 crontab" you can set environment variables in your crontab, by writing them before your cron lines.

There is also an example of a crontab so you just have to copy/paste it :

$ man 5 crontab | grep -C5 PATH | tail  # and files in /etc/cron.d. These files also have username fields, # that none of the other crontabs do.  SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin  # m h dom mon dow usercommand 17 * * * *  root  cd / && run-parts --report /etc/cron.hourly 25 6 * * *  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily ) 47 6 * * 7  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly ) 

So you can adjust your PATH or any environment variable to whatever you want. But this example seems enough for typical cases.