topic Re: Output redirection help in ksh script in Operating System - Linux

Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 10:32:00 GMT

I am running a backup script and I would like the output saved in a log file. I would appreciate a little help. Here is the actual backup line

{ fbackup $backup_type -u $verbose_option $nfs_option -g $graph_file $index_opt
} $logfile 1> $logfile

Here is what it looked like when it ran using (ksh -x scriptname )

+ 0< /bow/resp + fbackup -0 -u -n -g /bow/bowgraph -I /bow/backuplogs/25Apr06.full -c /bow/backup_config -d /bow/fbackupfiles/datesm (*output cut off*)
fbackup(1004): session begins on Tue Apr 25 11:01:25 2006
fbackup(3203): volume 1 has been used 7 time(s)
fbackup(3024): writing volume 1 to the output file /dev/rmt/0m
fbackup(3009): WARNING: File number 72630 (/orabackup/oradata/ediprod/redologs/ediprod_redo2.dbf)
was not successfully backed up
fbackup(3055): total file blocks read for backup: 25546882
fbackup(3056): total blocks written to output file /dev/rmt/0m: 26110005
fbackup(1030): warnings encountered during backup

I wanted the above output to go into the file pointed to by $logfile. I pointed standard output and stantard error to $logfile which was empty after the job ran. $logfile and all other variables in the above line are defined earlier in the script.

Any suggestions?

Re: Output redirection help in ksh script

harry d brown jr — Tue, 25 Apr 2006 10:37:44 GMT

{ fbackup $backup_type -u $verbose_option $nfs_option -g $graph_file $index_opt
} &1 1> $logfile

live free or die
harry d brown jr

Re: Output redirection help in ksh script

Peter Nikitka — Tue, 25 Apr 2006 11:23:20 GMT

Hi,

you are using different redirections to the same file - which one will win?

Configure the output an error stream instead:

1) use different files for stdout and stderr
{
cmd
} >outfile 2>errorfile

2) Redirect one stream to the other
{
cmd
} >outfile 2>&1

mfG Peter

Re: Output redirection help in ksh script

Rodney Hills — Tue, 25 Apr 2006 11:29:52 GMT

If you are running in a script, you have the option to assign STDOUT and STDERR before the fbackup command and thus capture all output. Example-

exec >$logfile 2>&1
date
fbackup ...
date

HTH

-- Rod Hills

Re: Output redirection help in ksh script

James R. Ferguson — Tue, 25 Apr 2006 11:53:32 GMT

Hi Mike:

Order is important here, too!

Run this script snippet:

# cat .redir
#!/usr/bin/sh
echo "from stdout"
print -u2 "from stderr"
exit 0

...Do this:

# ./redir 2>&1 1> /redir.log
from stderr
# cat redir.log
from stdout

Now:

# ./redir 1> /redir.log 2>&1
# cat redir.log
from stdout
from stderr

In the second case you achieve what you want. In the first case, STDERR was assigned to your terminal *and* then STDOUT was assigned to the file.

Regards!

...JRF...

#

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 12:12:59 GMT

Ok, so for I have tried what Harry recommended, the backups ran sucessfully so there were no errors but still I got output to the screen instead of to the file.

Actual code:
{ fbackup $backup_type -u $verbose_option $nfs_option -g $graph_file $index_opt
} &1 1>$logfile

Actual output

+ 0< /bow/resp 2>& 1 + fbackup -0 -u -n -g /bow/bowgraph -I /bow/backuplogs/25Apr06.full -c /bow/backup_config -d /bow/fbackupfilesm
fbackup(1004): session begins on Tue Apr 25 13:04:09 2006
fbackup(3203): volume 1 has been used 8 time(s)
fbackup(3024): writing volume 1 to the output file /dev/rmt/0m
fbackup(3055): total file blocks read for backup: 25676534
fbackup(3056): total blocks written to output file /dev/rmt/0m: 26241878

The output file is completely empty. Did I miss something?

Re: Output redirection help in ksh script

Rodney Hills — Tue, 25 Apr 2006 12:16:06 GMT

You can do as I suggested. But the error is you assign 2 before 1. Reverse them...

>$logfile 2>&1

HTH

-- Rod Hills

Re: Output redirection help in ksh script

James R. Ferguson — Tue, 25 Apr 2006 12:17:25 GMT

Hi (again) Mike:

With regard to your second question, see my post just above: "Order is important here, too!"

Regards!

...JRF...

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 12:24:27 GMT

James, I am running your script tests now and I am beginning to get what you are saying. It looks like I just need to change the order. I have a meeting in 6 minutes, I will retest after that.

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 14:13:35 GMT

Just got a chance to try James' suggestion and here is what I got.

{ fbackup $backup_type -u $verbose_option $nfs_option -g $graph_file $index_option -c $config_file -d $fbackupfiles -f $device
} $logfile 2>&1

fbackup(1004): session begins on Tue Apr 25 15:02:37 2006
fbackup(3203): volume 1 has been used 9 time(s)
fbackup(3024): writing volume 1 to the output file /dev/rmt/0m
fbackup(3055): total file blocks read for backup: 21220083
fbackup(3056): total blocks written to output file /dev/rmt/0m: 21787601

Still no output in the file. I will now try the method given by Rodney.

Re: Output redirection help in ksh script

Rodney Hills — Tue, 25 Apr 2006 14:22:53 GMT

Are those curly brackets you are using?

If so then the syntax requires a ; before the closing right curly bracket.

HTH

-- Rod Hills

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 14:29:48 GMT

This one didn't work either but I am confused as to why, it made sense.

{ fbackup $backup_type -u $verbose_option $nfs_option -g $graph_file $index_opt
} $logfile 2>&1

+ fbackup -0 -u -n -g /bow/bowgraph -I /bow/backuplogs/25Apr06.full -c /bow/backup_config -d /bow/fbackupfiles/dates -f /dev/rmt/0m
fbackup(1004): session begins on Tue Apr 25 15:18:36 2006
fbackup(3203): volume 1 has been used 10 time(s)
fbackup(3024): writing volume 1 to the output file /dev/rmt/0m
fbackup(1102): WARNING: unable to stat file /entsys/tmp/cos.003354981498422125.1385.6
fbackup(3005): WARNING: file number 33092 was NOT backed up
fbackup(1030): warnings encountered during backup
fbackup(3055): total file blocks read for backup: 21283397
fbackup(3056): total blocks written to output file /dev/rmt/0m: 21851691

Re: Output redirection help in ksh script

James R. Ferguson — Tue, 25 Apr 2006 14:50:25 GMT

Hi (again) Mike:

As Rodney noted, a a final semicolon is required after the last statement in curly braces. I agree that you last post seems correct otherwise. That aside, I use this in one of my scripts:

# ( /usr/sbin/fbackup -f $FB_DEV -0 -u -v -g $FB_GRF -V $FB_VOL -c $FB_CNF 2>&1 ; echo $? > $FB_XIT ) | tee -ia $FB_LOG

The approach I that I took here uses a sub process (and yes, there is not a semicolon in this syntax) but writes STDOUT and STDERR to ${FB_LOG} as well as the terminal.

Regards!

...JRF...

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 14:58:00 GMT

I have added the semi colon before the right bracket and still the output comes to the screen. From what I understand of the output and error redirection this should work

1>$logfile 2>&1

This fbackup command is inside a script and I am trying to save the output and/or error/warnings in the $logfile. I am apparently not seeing what is wrong with the syntax.

Re: Output redirection help in ksh script

Christian Tremblay — Tue, 25 Apr 2006 15:05:03 GMT

shouldn't your redirection line be:

2>&1 >> $logfile

Re: Output redirection help in ksh script

Mike Smith_33 — Tue, 25 Apr 2006 15:11:37 GMT

Some of the earlier answers were correct, it was my mistake in that I should have been using $log_file instead of $logfile. I would have found the answer much sooner.

Thanks for all the help and for putting up with my typo.