UNIX for Advanced & Expert Users

Dear all,

On my UNIX server there is an apache web log file. The rate of logging of data in this file is very high. I want to extract user logging log from this file in run time. As soon as the user logging log logged in this file I want to redirect this user log into another file.

I want to know which following method is more correct (system performance wise, cpu usage etc ) to do above explained task:

1. Do a ‘tail -f apache.log | <awk pattern to redirect the user logging log into another file>', this command will run as a daemon.
2. Write a Perl script which run as a daemon and continuously scan the file and if the user logging appeared and time stamp is new then fetch that log information and redirect it to another file.

Or is there any other way which is more efficient than above two specified?

Thanks in advance

Regards...
Zing_foru

If I'm restricted to choose from those two options, I'd go for the first one but there's more efficient way to accomplish this with apache logs - with SetEnvIF - take a look at this page, there are pretty good examples.

Hi sysgate

Thanks for providing the link.

I have gone trough the Apache log page that you provided. But still I am having some problems.

I studied the httpd.conf file which is on my server. The httpd.conf file already contain one CustomLog line.

Can I add one more CustomLog line as follows

CustomLog "|grep LaunchPage.nhtml" 2>&1 >> /tmp/user.log

Or is there any new configuration option to get only user logging and user loggout logs in a separate file?

Thanks and Regards...
zing_foru

I don't think you can use "grep" in SetEnvIf directive, honestly, I've done this two years ago, but I forgot how exactly...let me check the old files...In the meantime, you may check this liink and see if it will help.

I just checked some old config files... If you want to do Name Based Hosting, respectively user, just add vhost directive like :
Here you can add the path to the logs, and then wiht some mod_rewrite you can achieve the goal.