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Old 10-16-2003, 11:21 AM   #1
XFox
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Question Ambiguous output redirect


Hi,
I have this line in my crontab file:

*/10 * * * * cd /usr/local/setiathome-3.03.powerpc-apple-darwin1.2; ./setiathome -nice 19 1>/dev/null 2>/dev/null

When cron checks the crontab and launches the setiathome process all goes well, but if I cd to the setiathome folder and try to manually launch the process with the same command, that is:

./setiathome -nice 19 1>/dev/null 2>/dev/null

I get an error message from the shell that says:

Ambiguous output redirect.

and the process isn't launched.

Why?
I use the tcsh shell on Mac OS X 10.2.8.
TIA.
 
Old 10-16-2003, 12:20 PM   #2
slightcrazed
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I *think* this is because tcsh does not recognize bash style redirects (1>/dev/null). Can you launch the app without the redirects?

I don't use tcsh, so I don't know the proper syntax for the redirect that you are doing.

man tcsh might help out with this.

slight
 
Old 10-17-2003, 11:00 AM   #3
XFox
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Quote:
Originally posted by slightcrazed
I *think* this is because tcsh does not recognize bash style redirects (1>/dev/null). Can you launch the app without the redirects?
Yes, naturally.

Quote:
Originally posted by slightcrazed
I don't use tcsh, so I don't know the proper syntax for the redirect that you are doing.

man tcsh might help out with this.
Probably you're right, I searched in man tcsh and there is written that to redirect standard and diagnostic output the right sintax is:

>& \dev\null

But I'm still wondering why the same line in the crontab file works, and if I launch it from the shell it doesn't work.
Perhaps cron uses another shell?
If so, how can I know what shell it uses?
 
Old 10-17-2003, 11:11 AM   #4
slightcrazed
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Possible. I'll do some reading on cron and see if that is the case. Honestly, I don't use cron that often, so I never paid attention to which shell it uses.

slight
 
Old 10-17-2003, 11:27 AM   #5
whansard
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my crontab says
Shell=/bin/bash
at the beginning
most scripts are set to use sh or bash.
 
Old 10-17-2003, 07:29 PM   #6
XFox
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Thumbs up Resolved!

In my crontab file I haven't specified any shell.
Searching with Google I found this:
http://www.gsp.com/cgi-bin/man.cgi?s...&topic=crontab
It says "Several environment variables are set up automatically by the cron(8) daemon. SHELL is set to /bin/sh, []".
To prove this I have placed this line in my crontab:
*/1 * * * * echo $SHELL > ~/usedShell.txt
Then I looked at the file originated and is says exactly "/bin/sh"!
Thanks a lot for all the answers!
 
  


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