phpeveryday.com

<?php
exec("ping localhost", $output);
echo "<pre>".join("\r\n", $output)."</pre>";
?>

Ping command depend on Operating System. I use Win XP. And I just check localhost. You can try other network host by replace localhost above. Result may like this:

Pinging DIGI01 [127.0.0.1] with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms