11c08-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 56 行

<?php
// A function to do a sanity check on a URL ... Since we are assuming
// that this is coming from user input, we will require it be a full
// URL, and not a relative one
function validate_url($url) {
    // Use parse_url to break the URL into parts for us:
    $up = parse_url($url);
    
    // If scheme, host, or path don't exist, or complete failure: INVALID
    if (!$up || !$up['scheme'] || !$up['host'] || !$up['path']) {
        return false;
    }
    
    // If the scheme is anything besides http(S) or ftp: Fail
    if (!( ($up['scheme'] == 'http') || 
           ($up['scheme'] == 'https') || 
           ($up['scheme'] == 'ftp'))  ) {
        return false;
    }
    
    // We made it here, it looks good to us.
    return true;
}

// Function that will actually take a url, and attempt to contact the server
// if it can't access the remote file, it returns false, else true.
function check_url($url) {
    // Request only the headers, no reason to download the whole file
    // Note that this call will only handle https connections if PHP was
    //  compiled with SSL support.
    $output = @get_headers($url);
    
    // Return appropriately
    return $output ? true : false;
}

// Test a few URLs
$urls = array('http://eliw.com/', 'http://php.net/get_headers', 
    'gopher://bob.com/', 'https://lawn.tractor/models/1.php', 
    'http://hubblesite.org/news/2006/01/', 'http://digg.com/');

// Loop over these, check if they appear valid, if they do, try to access
foreach ($urls as $r) {
    // If this does not validate:
    if (!(validate_url($r))) {
        // Set the display accordingly:
        $disp = 'Did not validate!';
    } else {
        // Try to access it, and set display accordingly
        $disp = check_url($r) ? 'GOOD!' : 'Could not contact...';
    }

    // Display this
    echo "<p>{$r} = {$disp}</p>\n";
}
?>