Pete Freitag Pete Freitag

Monitoring Log files in Realtime on Unix

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Here's a handy trick for monitoring log files on unix, linux or mac's.

SSH on to your server then type:

tail -f /var/log/httpd/access_log

The above command will show you the last few lines of the log file, this is no suprise if your fimiliar with tail command. However the -f option will print to your console any new lines added to the log file in realtime. So you can get a live view of the traffic on your server.


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Monitoring Log files in Realtime on Unix was first published on December 06, 2006.

If you like reading about logs, unix, commands, or tail then you might also like:

Comments

Multitail <http://www.vanheusden.com/multitail/> is even more useful.
It displays multiple logfiles in split windows on your console and can even merge several logfiles in one view or show you program output (eg. lsof -i)
Give it a go!
by Flo on 12/06/2006 at 4:54:50 PM UTC
I've also found it helpful to use grep if you want to filter your "realtime" tailed output by IP address, page name, etc.

tail -f /var/log/httpd/access_log | grep '192.168.1.100'
by Bernie Dolan on 12/07/2006 at 11:41:17 AM UTC
works on windows too, if you install cygwin and add C:\cygwin\bin to your path - http://www.cygwin.com/
by thad on 12/07/2006 at 12:24:35 PM UTC
How do tail on a log file that will be created in the current working directory?
by leofox on 11/18/2008 at 8:49:10 AM UTC
This is fantastic. Thanks for the tip :)
by Joe on 08/13/2010 at 4:48:31 PM UTC
This doesnt work in case of rolling logs. As soon as the log is archieved , the command still keeps the pointer on the archieved file and not on the new file. the following script is good and can help monitoring rolling logs.

http://www.buggybread.com/2012/03/log-monitoring-shell-script-to-send.html
by Vikas on 02/16/2013 at 12:16:17 PM UTC