Very Computer

by **Sébastien FERRANDE** » Fri, 29 Sep 2000 04:00:00

Every time I schedule a cron job I get a mail with "Output from "cron"
comman" as subject. How can I redirect the standard error output to
avoid being sent these e-mails ? Do I have to send it to the null file
? I have csh.

by **Martin Pau** » Fri, 29 Sep 2000 04:00:00

> Every time I schedule a cron job I get a mail with "Output from "cron"
> comman" as subject. How can I redirect the standard error output to
> avoid being sent these e-mails ? Do I have to send it to the null file ?

Add ">/dev/null 2>&1" to the end of the crontab entry.

Quote:> I have csh.

cron jobs are run by /bin/sh, so your login shell doesn't matter.

hth, mp.
--
Martin Paul | Systems Administrator

Liechtensteinstrasse 22, A-1090 Wien | Tel: 01 4277 38803
http://www.par.univie.ac.at/ | Fax: 01 4277 9388

by **Sébastien FERRANDE** » Fri, 29 Sep 2000 04:00:00

Ok, thanks. If I get the point, >/dev/null 2>&1
means that you're redirecting the error output (2, isn't it ?) to /dev/null (&1
means the first argument, isn't it ?)

> > Every time I schedule a cron job I get a mail with "Output from "cron"
> > comman" as subject. How can I redirect the standard error output to
> > avoid being sent these e-mails ? Do I have to send it to the null file ?

> Add ">/dev/null 2>&1" to the end of the crontab entry.

> > I have csh.

> cron jobs are run by /bin/sh, so your login shell doesn't matter.

> hth, mp.
> --
> Martin Paul | Systems Administrator

> Liechtensteinstrasse 22, A-1090 Wien | Tel: 01 4277 38803
> http://www.par.univie.ac.at/ | Fax: 01 4277 9388

by **Martin Pau** » Fri, 29 Sep 2000 04:00:00

> Ok, thanks. If I get the point, >/dev/null 2>&1
> means that you're redirecting the error output (2, isn't it ?) to /dev/null (&1
> means the first argument, isn't it ?)

close, but not quite :)

the number is a file descriptor, where 1 stands for stdout, and
2 is stderr (error output).

Quote:>/dev/null (or 1>/dev/null) redirects everything that goes to stdout

do /dev/null, and 2>&1 redirects everything that goes to stderr to
where descriptor 1 (stdout) points.

hth, mp.
--
Martin Paul | Systems Administrator

Liechtensteinstrasse 22, A-1090 Wien | Tel: 01 4277 38803
http://www.par.univie.ac.at/ | Fax: 01 4277 9388

by **Peter Sundstro** » Sat, 30 Sep 2000 04:00:00

>Ok, thanks. If I get the point, >/dev/null 2>&1
>means that you're redirecting the error output (2, isn't it ?) to /dev/null
(&1
>means the first argument, isn't it ?)

2>&1 means associate standard error (file desc 2) with standard out (file
desc 1). It's a shorter way to write: command 1>/dev/null 2>/dev/null

Very Computer

redirecting output from "cron" command

redirecting output from "cron" command

redirecting output from "cron" command

redirecting output from "cron" command

redirecting output from "cron" command

redirecting output from "cron" command