I normally have several problems with how cron executes scripts as they normally don't have my environment setup. Is there a way to invoke bash(?) in the same way cron does so I could test scripts before installing them?
A:
I don't believe that there is; the only way I know to test a cron job is to set it up to run a minute or two in the future and then wait.
jn80842
2010-01-25 21:00:16
This is why I'm asking simulate
Jorge Vargas
2010-04-07 21:25:43
+2
A:
Cron provides only this environment by default :
HOMEuser's home directoryLOGNAMEuser's loginPATH=/usr/bin:/usr/sbin:.SHELL=/usr/bin/sh
If you need more you can source a script where you define your environment before the scheduling table in the crontab.
gregseth
2010-01-25 21:02:44
+3
A:
You can run:
env - your_command arguments
This will run your_command with empty environment.
dimba
2010-01-25 21:08:21
+1
A:
By default, cron executes its jobs using whatever your system's idea of sh is. This could be the actual Bourne shell or dash, ash, ksh or bash (or another one) symlinked to sh (and as a result running in POSIX mode).
The best thing to do is make sure your scripts have what they need and to assume nothing is provided for them. Therefore, you should use full directory specifications and set environment variables such as $PATH yourself.
Dennis Williamson
2010-01-25 21:57:27
This is exactly what I'm trying to solve. We get tons of problems with scripts that assume something by mistake. Doing full paths and setting env variables and all the junk ends up with horrible huge unmaintainable cron lines
Jorge Vargas
2010-04-07 21:26:45
re *sh sorry I grew up with bash = shell so it's hard to me to remember the alternatives (and sometimes better) shells.
Jorge Vargas
2010-04-07 21:29:32
Dennis Williamson
2010-04-07 23:15:43
+5
A:
Create a cron job that runs env and redirects stdout to a file. Use the file alongside "env -" to create the same environment as a cron job.
Jens Carlberg
2010-01-25 22:03:35
That will give you an empty environment. When you run scripts through cron, the environment isn't empty.
Jens Carlberg
2010-04-07 21:56:39
+2
A:
Don't forget that since cron's parent is init, it runs programs without a controlling terminal. You can simulate that with a tool like this:
Randy Proctor
2010-01-26 13:38:01
+4
A:
Add this to your cron:
30 08 * * * env > ~/cronenv
After it runs, do this:
env - `cat ~/cronenv` /bin/sh
This assumes that your cron runs sh. I believe this is the default.
mmccoo
2010-03-30 15:34:41