16c06-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 48 行

<?php
// This program will run 'forever' checking the status of a provided webpage

// Prepare by setting a timezone, mail() uses this.
date_default_timezone_set('America/New_York');

// Ensure that the email, URL, and seconds were provided:
if ($argc < 4) {
    exit("Proper Usage: {$_SERVER['PHP_SELF']} <email> <url> <frequency>");
}

// We have the right number of parameters, let's assume they are correct:
$email = $argv[1];
$url = $argv[2];
$seconds = $argv[3];

// Make sure that we don't timeout:
set_time_limit(0);

// We need to do an initial grab of the URL:
$saved = @file_get_contents($url);

// Now, loop forever:
while (true) {
    // Sleep for X seconds before trying to access the page again:
    sleep($seconds);
    
    // Ok, get a new copy of the page:
    $new = @file_get_contents($url);

    // Compare them to see if there is any difference:
    if ($saved !== $new) {
        // The page changed!  First of all, save the 'new' as the 'saved'
        $saved = $new;
        
        // Now time to send that email!
        mail($email, "Page Changed - {$url}", "
The URL that I was told to watch:
{$url}

Appears to have changed.  I thought you might want to know that.

Your friend,
Automatic URL Watcher Robot
", "From: {$email}");
    }
}
?>