Отслеживание работоспособности ваших серверов

#!/usr/local/bin/php
<?php
ini_set("max_execution_time", 0);

$default_host = "host.com";
$default_mail = "sms-gate";

$host = $argv[1] ? escapeshellcmd($argv[1]) : $default_host;
$mail = $argv[2] ? $argv[2] : $default_mail;

$last_checked_status = check_status();
mail($mail, "INFO", "$host monitoring started at ".date("H:i").", current status: ".($last_checked_status ? "UP" : "DOWN"));

function check_status(){
 global $host;
 $result = exec("ping -c 4 $host");
 return (strpos($result, "0 packets received") > 0) ? 0 : 1;
}

function is_change_status(){
 global $last_checked_status;
 global $mail;
 global $host;
 $status = check_status();
 if ($status != $last_checked_status){
  $last_checked_status = $status;
  mail($mail, "INFO", "$host ".($last_checked_status ? "UP" : "DOWN")." at ".date("H:i"));
 }
}

while (true) {
 is_change_status();
 sleep(60);
}
?>