User environment for cron jobs

[dictum9]

How do I control the environment when I run cron jobs, in other words what startup file is getting sourced in? $HOME/.login? I doubt $HOME/.profile is getting sourced in.

[Mark Greene_1]

You are right, it is not. You have to explicitly set the environment. Cron does not go through logind so none of the usual events that happen during login happen in cron.

mark

[Pete Randall]

"what startup file is getting sourced in?"

Answer: none

Cron runs with a minimal evironment. Check the man page for crontab if you want to know the details. Your best bet is to source a profile that will set the PATH and whatever environment variables you will need. You could source /etc/profile or $HOME/.profile or some other profile that combines these to give you what you need.

You could also explicitly define the variables and PATH in your cron job - whichever works for you.


Pete

[Carlos Roberto Schimidt]

If you dont want explicitly set the environment, is possible you put in first line from script to run in cron:

. $HOME/.profile

But you have to set HOME variable.

Schimidt

[Pete Randall]

Actually, to quote the man page:

"cron supplies a default environment for every shell, defining:

HOME=user's-home-directory
LOGNAME=user's-login-id
PATH=/usr/bin:/usr/sbin:.
SHELL=/usr/bin/sh

Users who desire to have their .profile executed must explicitly do so in the crontab entry or in a script called by the entry."


Pete

[James R. Ferguson]

Hi:

The 'cron' environment is quite sparse as the manpages for 'crontab' will divulge. For example, your PATH consists only of '/usr/bin' and '/usr/sbin'.

The most appropriate way, in my opinion, to define commonly used environmental variables is to collect them in a standalone file that can be sourced (read) *either* by your '$HOME/.profile' as it is processed during login() or by scripts that you run and/or cron.

Regards!

...JRF...

[Arunvijai_4]

Hi etc,

"cron" doesnt take any ENV variables. You need to set them individually,

-Arun

[A. Clay Stephenson]

As has been mentioned cron has an intentionally sparse environment. Generally, it is not a good idea to source a user's .profile within a cron'ed script. Why? Because the default .profile's under HP-UX contain commands which extect stdin and stdout to be a tty device (i.e. a terminal) and can hang if those conditions are not met (e.g. under cron).

The least evil approach I have found is to setup a separate file to set and export any needed variables, e.g. /usr/local/bin/myenv.sh, and have the user's .profile AND your cron'ed script source this file via the . (dot) operator.
This sourced file must not contain any return or exit statements as that will have the effect of terminating the process.