topic Redirection in csh in Operating System - HP-UX

Redirection in csh

parmy_4 — Mon, 23 Aug 2004 08:28:16 GMT

Hi techies,
Could any one explain (or redirect) me to know more about Outpur redirection in C Shell. I want both error and regular output to be written into a file and should also display at the Standard Output.

Thanks in Advance,
-Parmy

Re: Redirection in csh

Simon Hargrave — Mon, 23 Aug 2004 09:11:09 GMT

csh is very bad for this kind of thing.

the nearest you can get is something like: -

touch log ; tail -f log & ; your_command >& log

This should give an idea of the inflexibilities of the csh, in various areas: -

http://www.ooblick.com/text/CshProgrammingConsideredHarmful.html

Re: Redirection in csh

Mark Ellzey — Tue, 24 Aug 2004 08:43:35 GMT

Parmy,

You can also use the 'tee' command. Check out man tee(1).

In my scripts, I'll check if it is interactive, and if so, then I'll pipe the output throught tee. In this way, the user gets to see the output on the screen, and the output is also being saved in a log file.

Something like this:

ls -l /etc | tee /tmp/logfile.log

Regards,
Mark

Re: Redirection in csh

Simon Hargrave — Tue, 24 Aug 2004 08:49:56 GMT

Only problem with tee is it doesn't capture stderr. In sh that's fine you can 2>&1, but not in csh.

Re: Redirection in csh

Muthukumar_5 — Tue, 24 Aug 2004 10:52:07 GMT

Redirection can be done based on the output type weather on STDOUT (output mode ) and STDERR ( error mode).

File descriptor 1 is used for standard ouput and 2 is for standard error.
hostname 1> /tmp/hostname.file

hostname output will be redirected to /tmp/hostname.file

IF you want to write output and error in on same file then,

-- file.csh --
hostname
trr
--------------

# csh file.csh 1>/filenamewithpath 2>&1

It will redirect all output / error to that file or

# csh file.csh 1>/filenamewithpath 2>/filenamewithpath

You can also use aslike as,

# csh file.csh 1>>/filenamewithpath 2>>/filenamewithpath

Difference between >> and > is

>> - it will append contents or create new file and add more contents

> - it will create or make null the existing file

HTH.
+Muthu+

Re: Redirection in csh

Carlo Corthouts — Wed, 25 Aug 2004 09:17:03 GMT

You also can use the "tee" command for that.

Re: Redirection in csh

Muthukumar_5 — Wed, 25 Aug 2004 09:29:36 GMT

hai,

another command be used for this as script

script test.log
hostname
uname -a
exit

cat test.log will contain your log informations there.

-muthu