PHP Examples: Very simple image replication using FTP and GD

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Very simple image replication using FTP and GD.

This is a very basic script, again stripped down from a larger piece of code.

It allows you to replicate images across a number of servers using an "on demand" system.

The remote servers would display images using something along the lines of

If the image does not exist locally on the remote.com server, the image is FTPed from a master location, then displayed. If image exists already, then it is simply displayed right away.

What this script does not allow for is if the file is deleted or updated on the master machine.


<?php

// Root is wherever the images may stored

$root = "/var/www/html/common_images/";

// Filename is the name of the file on the
// source server

$root_file = $root.$filename;

// Does it exist locally?

if(!file_exists($root_file))
{

// If no ....

    $dir_tree = explode("/",$root_file;);
    array_pop($dir_tree);

// Make the directory for the image to sit in
// mkdirr makes recursive directories

    mkdirr(implode("/",$dir_tree),0777);

// Open the new file in write mode

    $fp = fopen($root_file, 'w');

// FTP back to our source server
// You would not have to use FTP to do this,
// for the source this example came from, it was
// required.

    $conn_id = ftp_connect("ftp.server.com");

    $login_result = ftp_login($conn_id, "username", "password");

// FTP_GET the file into an open file handle 
// We assume the file is in the images dir ... doesn't
// have to be

    if (!ftp_fget($conn_id, $fp,"/public_html/images/".$filename;, FTP_BINARY)) 
    {
    
// Whoops
        return;
    }
    
// else tidy up a bit

    ftp_close($conn_id);
    fclose($fp);
}

// So we now have the image on our server
// Just use GD to create a new image.
// We could be more intelligent here and 
// check what file the source is ... I
// just convert everything to a JPG.

$im = imagecreatefromjpeg($root_file);
header("Content-type: image/jpeg");
imagejpeg($im,80);
imagedestroy($im);

function mkdirr($pathname, $mode = null)
{
    // Check if directory already exists
    if (is_dir($pathname) || empty($pathname)) {
        return true;
    }
 
    // Ensure a file does not already exist with the same name
    if (is_file($pathname)) {
        trigger_error('mkdirr() File exists', E_USER_WARNING);
        return false;
    }
 
    // Crawl up the directory tree
    $next_pathname = substr($pathname, 0, strrpos($pathname, DIRECTORY_SEPARATOR));
    if (mkdirr($next_pathname, $mode)) {
        if (!file_exists($pathname)) {
            return mkdir($pathname, $mode);
        }
    }
    return false;
}
?>