How to process incoming messages in Linux?

Question

linux

Given:
CentOs 6.5 minimal
Some port (let it be 7777) sometimes receives messages like either 'Ok' or 'Error'.
It is necessary that when the 'Error' message arrives on the port, the script '/opt/omgErrorNoPLS.sh' is executed.
The idea that came to my mind, but I don't really know how to implement it:
Raise on the nhinx server with php support. In php describe:

<?php
if (message=='Error')
  exec('/opt/omgErrorNoPLS.sh');
?>

(Not very sure about what is written above). The main problem is that I don't understand how to make php process exactly the string that arrived in one packet on 7777.
Thanks in advance for your help.

Answer 1

Python has a nice built- in socket library .

Answer 2

inetd, xinetd.