How to change cron shell (sh to bash)?

Question

Is it possible to make commands in crontab run with bash instead of sh? I know you can pass commands to bash with -c, but that's annoying and I never use sh anyway.

don't really know what you're doing (not familiar with cron) but if you are running a script then adding a shebang to it should work, not sure if I am correct. — Alvin Wong, Oct 11 '13 at 17:18

score 160 · Accepted Answer · answered Oct 10 '13 at 15:36

160

You should be able to set the environment variable prior to the cron job running:

SHELL=/bin/bash
5 0 * * *       $HOME/bin/daily.job >> $HOME/tmp/out 2>&1

answered Oct 10 '13 at 15:36

slm

369,824

3

is it possible to also make it read .bashrc? – Fluffy Oct 10 '13 at 15:46
4

@Fluffy .bashrc is - by definition - for interactive shells; so when started via cron, bash will only read this file if it is an interactive shell. – umläute Oct 10 '13 at 16:03
1

@umläute, ok, so where should I put env vars that should exist in non-interactive non-login shells? – Fluffy Oct 10 '13 at 16:06
29

I was able to make it read bashrc by adding BASH_ENV="/root/.bashrc". Thanks – Fluffy Oct 10 '13 at 16:12
4

@Fluffy you should make that an answer – vol7ron Apr 11 '17 at 21:37
4

Regarding .bashrc, bash -l looks useful, http://blog.endpoint.com/2015/02/cron-wrapper-keep-your-cron-jobs.html – mpapec May 04 '17 at 05:15
1

Note that I've observed that SHELL requires to be set in each crontab (e.g. the one you modify with crontab -e) and setting it only in /etc/crontab won't apply globally. – Jaime Hablutzel Apr 02 '20 at 21:10
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@JaimeHablutzel that's correct, the system crons and user crontabs (crontab -e) are independent from each other – slm Apr 02 '20 at 23:49
Will this apply to the entire cron file? Or just the remaining jobs in the crontab lexically? – Sridhar Sarnobat Mar 23 '21 at 22:35
I wonder if I can do SHELL=/bin/sh 2>/tmp/cron_errors.log. Finding errors in cron jobs is a pain. Am trying now. – Sridhar Sarnobat May 01 '22 at 22:55
/usr/bin/bash vs /bin/bash – CS QGB Jan 11 '23 at 14:29

How to change cron shell (sh to bash)?

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