UNIX for Dummies Questions & Answers

Hello!

I have an entry on my crontab.

10 00 * * * /bscsprod/bscs/prod/523/bin/tehcron.sh

$ /bscsprod/bscs/prod/523/bin/vi tehcron.sh
nohup teh -t -f > /dev/null &
~
~
~
~
~
~
~
~
"tehcron.sh" 13 lines, 365 characters
but executing the script from the commandline, it works.
$ /bscsprod/bscs/prod/523/bin/tehcron.sh
$ /bscsprod/bscs/prod/523/bin:INFC $ ps -ef|grep teh
bscsprod 4983 1 6 20:15:44 ttyp3 0:00 teh -t -f

what are the permissions on your script? What does cron log to your cron-logfile/syslog?

Try adding the standard #! line to the top of your script, as well as these modifications:

Code:

#!/bin/sh
nohup teh -t -f > /dev/null < /dev/null 2> /dev/null & disown

I've been left wondering why my ssh window wouldn't close when it turns out I left things running still using the terminal's stdin and stderr.

Except for Linux, few versions of unix have a /bin/sh that supports disown.

Good to know. Is it that they don't need it, or do they simply not support leaving processes behind?

Neither one. disown is simply a useful command invented by the bash developers and not available in other shells. I would like to see it in ksh. It's not clear why you think this stuff might be useful here though. There is no terminal involved with cron jobs unless the cron job opens one. So there is no controlling terminal to send a hup. ssh is different because a pty is involved. It would take an explicit kill -1 to send a hup to a cron job.

But closing 1 and 2 or redirecting them to /dev/null is a good idea, cron tend to gather these up and mail them to the user. People who write poor cron jobs then get a lot of mail which they never read and it fills up /var.