PHP Functions Essential Reference

getservbyport

mixed getservbyport( int port, string protocol_type) 

port	Name of the service
protocol_type	Name of the protocol; either tcp or udp

Gets the name of a service running on a port.

Returns: Service name; FALSE on error

Description: getservbyport() returns the name of the service running on a port under the given protocol, as defined in your system’s /etc/services or c:\windows\services file. If the protocol is not recognized, the function returns FALSE.

Availability:

UNIX, Windows

Version:

4.0b4+

See also:

getservbyname() 

Example:

23.12. Find out what service listens on a given port

<?php $port = 23; $protocol = 'tcp'; $service = getservbyport ($port, $protocol) or die ("No service is assigned to port $port using the $protocol ...