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Realtime lines per second in a log file

Terminal - Realtime lines per second in a log file
tail -f logfile | logtop
2012-06-24 19:18:30
User: Sizeof
Functions: tail
Realtime lines per second in a log file

logtop show number of lines per second, also classify them so you can show a "top" of every aspect of your logfile :

tail -f access.log | awk '{print $1; fflush();}' | logtop


There is 1 alternative - vote for the best!

Terminal - Alternatives
tail -f access.log | pv -l -i10 -r >/dev/null
2010-04-29 21:02:01
User: dooblem
Functions: tail
Tags: tail pv

Displays the realtime line output rate of a logfile.

-l tels pv to count lines

-i to refresh every 10 seconds

-l option is not in old versions of pv. If the remote system has an old pv version:

ssh tail -f /var/log/apache2/access.log | pv -l -i10 -r >/dev/null

grep <something> logfile | cut -c2-18 | uniq -c
2010-04-29 11:26:09
User: buzzy
Functions: cut grep uniq
Tags: uniq grep cut

The cut should match the relevant timestamp part of the logfile, the uniq will count the number of occurrences during this time interval.

tail -f /var/log/logfile|perl -e 'while (<>) {$l++;if (time > $e) {$e=time;print "$l\n";$l=0}}'
2011-06-21 10:28:26
User: madsen
Functions: perl tail time
Tags: perl tail

Using tail to follow and standard perl to count and print the lps when lines are written to the logfile.

tail -F some.log | perl -ne 'print time(), "\n";' | uniq -c
tail -n0 -f access.log>/tmp/tmp.log & sleep 10; kill $! ; wc -l /tmp/tmp.log
2010-04-29 21:23:46
User: dooblem
Functions: kill sleep tail wc
Tags: tail kill wc sleep

Another way of counting the line output of tail over 10s not requiring pv.

Cut to have the average per second rate :

tail -n0 -f access.log>/tmp/tmp.log & sleep 10; kill $! ; wc -l /tmp/tmp.log | cut -c-2

You can also enclose it in a loop and send stderr to /dev/null :

while true; do tail -n0 -f access.log>/tmp/tmp.log & sleep 2; kill $! ; wc -l /tmp/tmp.log | cut -c-2; done 2>/dev/null

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