saving out put to file - a better way ??

[someone_4]

I am writtinga script and I want to save the out put to a file. This is how I am doing it now. I use >> to apend to the file.
Is there a better way to do this then using
>> on everyline ?
------------------
echo "HP9000" >> daily.txt
remsh boxname -l root "tail -n30 /var/adm/syslog/syslog.log" >> daily.txt
----------------

[James R. Ferguson · Accepted solution]

Hi Richard:

Yes, duplicate the stdout descriptor. Try this:

#!/usr/bin/sh
exec >&1 >> /tmp/output
echo "It's $(date)"

Notice that all your output goes to the file /tmp/output without the need to redirect it as you go.

Regards!

...JRF...

[Curtis Larson]

you can use command grouping

sub shell grouping:
(
your stuff
) >> file.out

your code will run in a sub shell environment which means there will be no side effects, ie if you change variables in the grouping once your out of the grouping your changes won't be there. If you do nesting you'll need to put white space between the parentheses to avoid arithmetic evaluation.

you can also do a brace grouping:

{
your stuff
} >> file.out

[Maureen Gunkel]

Richard,

Another way to do it is to specify the output file when you run the script, like so:
./myscript >> daily.txt
Just a thought,
Mo

[Dan Hetzel]

Hi Richard,

James definitely showed you the way to go.

Nevertheless, in his example, standard error will not be redirected to the file as '>&1' comes before '>>'.
If you want both standard error and standard output to be redirected you could use the following constructs:
exec > /tmp/output 2>&1 # to redirect both in same file
exec > /tmp/output 2>/tmp/error # to redirect in different files


Best regards,

Dan

[Rodney Hills]

Sidenote-

Within the KSH you can write the output to a running program. Use "exec >&p". I use it in my spooler print drivers to write to jetdirect connected printers.

/opt/hpnp/hpnpf -x 192.16.0.10 |&
exec >&p

From then on, all stdout from the script will go to the stdin of program hpnpf.

[Mark Mitchell]

How about
| tee -a /usr/tmp/filename