Running a cron job from another shell

Question

I would like cron to run a script from a specific shell (Zsh). I thought the following would work:

00 02 * * * exec zsh; /path/to/script.sh

but apparently it doesn't, why?

This also made me wonder, how do I find out what shell and init scripts does cron run first prior to running the entry in crontab?

Is script.sh a zsh script or do you want zsh to launch an sh script? What's the exec supposed to do? — terdon, Apr 27 '14 at 21:24
Thanks @Ghassan. I didn't have a working shebang, partly because of I was suffering from the same problem reported here. I should be able to fix this now. — Josh, Apr 28 '14 at 12:24

score 7 · Accepted Answer · answered Apr 27 '14 at 19:52

7

How about:

00 02 * * * exec /usr/bin/zsh /path/to/script.sh

That will tell zsh to run the script. Now you want it to be run in zsh doesn't matter what, just add the shebang in the start:

#!/usr/bin/zsh
the_rest

answered Apr 27 '14 at 19:52

Braiam

35,991

1

why is everybody using an 'exec' before the shell command in cron? Simply using '/usr/bin/zsh /path/to/script.sh' is sufficient and exec is really unnecessary. – mdpc Apr 28 '14 at 01:36

score 3 · Answer 2 · answered Apr 27 '14 at 19:57

3

Cron has several enviromental variables configured in /etc/crontab, specifically SHELL and PATH. The default value for SHELL is /bin/sh. So unless this is changed or otherwise specified in a script, cron will execute commands using sh.

answered Apr 27 '14 at 19:57

Creek

5,062

NOTE: Some versions of cron allow specification of some global variables. To be sure checkout the man pages for cron, crond, and crontab for your particular distribution. – mdpc Apr 28 '14 at 01:37

Running a cron job from another shell

2 Answers2