tar command output redirection

ah_kayyali · 03-16-2006, 09:58 AM

hellooooooooooz
i am trying to use the tar command,, i used to use the script i made,, but one time i checked the tape and found some file not backed, i ran the script again and did nothing, just watching the output on screen, i triedto use output redirection but i can't redirect the errors only to a log file, here what i used
tar -cvf tarfile.tar f1 f2 f3 f4 f5 2>tar.log
and i found that the file tar.log holds the same output from both stdout and the stderr,,

do u have any idea about redirecting the errors only to the log file?????

thx in advance.

druuna · 03-16-2006, 10:11 AM

Hi,

The given command (tar -cvf tarfile.tar f1 f2 f3 f4 f5 2>tar.log) should work: Errors, if any, to tar.log and normal output to screen.

You are talking about a script, could it be that the script already redirects the output?
Does the tar command work when typed at the prompt?

Not much to go on, but I hope it helps anyway.

ah_kayyali · 03-19-2006, 02:59 AM

i am still having the same result even when i run the command on the prompt?, also i checked the script and found nothing redirecting the stderr to anything,,, i wish to find a solution

pixellany · 03-19-2006, 06:02 AM

Scanning man tar did not give an answer, but here is a GUESS:
The substantive output of tar goes to the specified file---not to "stdout". Thus, the only thing that I would expect to go to stdout would be errors.
What happens if you explicity send stdout to one file, and stderr to another?

druuna · 03-19-2006, 06:30 AM

Hi again,

Which shell are you using? Could it be that you are using a (t)csh shell? Using bash/ksh the tar command given works, if I try the same with a (t)csh shell it does not work.

If you are using a (t)csh shell try the following:

( tar -cvf tarfile.tar f1 f2 f3 f4 f5 > stdout_file ) > & stderr_file

Hope this helps.