if the file changes send email about diff

[J65nko]

On Sun, Feb 6, 2011 at 2:33 PM, kellyremo <kellyremo at zoho.com> wrote:
>
> I have 2 script. Script "A", Script "B".
>
> Script "A" is regulary watching the "dhcpacks" [dhcp release is configured to 2mins] in the logs, for the past 2 minutes. it writes the MAC addresses to a file [/dev/shm/dhcpacks-in-last-2min.txt] every 2 minutes. Ok, this is working, active clients are in this file. Super!
>
> Script "B": http://pastebin.com/raw.php?i=wvhwhPWu
> I'm trying to create a script, that watches the changes in "/dev/shm/dhcpacks-in-last-2min.txt" file [in every 1 sec]. Ok. But: my "watcher" script [the pastebined] is not working fine...sometime it works, sometime it send that someone "XY logged out", but it's not true! nothing happened, and the problem is not in the Script "A".
>
> Can someone help me point out, what am i missing? How can i watch a file [in every sec], that contains only MAC addresses, and if someone doesn't get dhcpack in 2 minutes, the file "/dev/shm/dhcpacks-in-last-2min.txt" changes, and that clients MAC address will be gone from it, and i need to know, who was it [pastebined my script..but somethings wrong with it].

You are attempting to re-invent the wheel called "revision control
system" ;) Your FreeBSD box has a simple revision control system
called 'rcs'. It will do the most things you are trying to emulate in
your shell script.

Read the rcsintro(1) man page how to get started.