since: Stateful Tail

since is a unix utility similar to tail. Unlike tail, since only shows the lines appended since the last time. It is useful to monitor growing log files

The below example shows how since can be used to quickly track down a change in /var/log:

~# since /var/log/* >& /dev/null  
~# logger "hello world"
~# since /var/log/* 
==> /var/log/messages [nothing new] <==
==> /var/log/user.log <==
May  5 13:11:34 hostname root: hello world

This is useful when one wants to locate an error message - simply trigger the error in place of running logger in the above example

since can be useful in a shell alias (add to ~/.bashrc) to monitor important log files, as shown below

alias dosince='since /var/log/{syslog,kern.log,apache/error.log}'
since is released under the GNU General Public License




Karl Vogel has implemented since style functionalityin Perl
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