Checking if image is not broken from external site

[LanceT]

Lets say I want to do a simple image code like

 

<img src = "www.yahoo.com/image.jpg">

 

And I want to check if the image hosted on Yahoo wasn't a broken image (if it is broken, then I will use different code).

 

What function can I use to do this?

[kathas]

well if by broken you mean inexistent...

then you might try to fopen() it and see what happens...

 

I haven't actually tried that but if fopen() gets redirected search the result for 404 else it should return false that it isn't able to open the requested file...

[LanceT]

well if by broken you mean inexistent...

 

By broken I mean that if you went to the actual site, you would get a 404 Not Found error.

[Guest prozente]

You can connect to a server with a socket using TCP on port 80 and submit a HEAD HTTP request

 

I'll use the telnet program as an example to illustrate the socket connection.

 

Say you wanted to see if the file

 

http://phpfreaks.com/forums/Themes/default/images/icons/profile_sm.gif

 

existed on the server

 

telnet phpfreaks.com 80

HEAD /forums/Themes/default/images/icons/profile_sm.gif HTTP/1.0

Host: phpfreaks.com

 

Now hit enter twice and you'll receive a response

 

HTTP/1.1 200 OK
Date: Thu, 19 Apr 2007 02:55:54 GMT
Server: Apache/2.2.4 (Unix) DAV/2 PHP/5.2.1
Last-Modified: Tue, 09 Jan 2007 18:46:42 GMT
ETag: "070000-230-f8916410"
Accept-Ranges: bytes
Content-Length: 560
Connection: close
Content-Type: image/gif

 

This shows the file does exist, if it didn't you would receive a 404 error

 

for example

 

telnet phpfreaks.com 80

 

HEAD /forums/Themes/default/images/icons/nonexistant.gif HTTP/1.0

Host: phpfreaks.com

Hit enter twice

 

The response you would receive would be

 

HTTP/1.1 404 Not Found
Date: Thu, 19 Apr 2007 03:01:56 GMT
Server: Apache/2.2.4 (Unix) DAV/2 PHP/5.2.1
Connection: close
Content-Type: text/html; charset=iso-8859-1

 

This shows the file doesn't exist

 

 

Now to do this in PHP you'd use a socket

and craft the HTTP packet and send it to the server.

 

Look at Example 2203 in the PHP manual on the sockets page, it shows a good example.

 

 

 

[MadTechie]

what about this, if the image fails it will display an image saying "Error loading $imgname"

 

 

use

<img src = "testimage.php?file=http://www.yahoo.com/image.jpg">

 

create script below

filename = testimage.php

<?php
function LoadJpeg($imgname)
{
    $im = @imagecreatefromjpeg($imgname); /* Attempt to open */
    if (!$im) { /* See if it failed */
        $im  = imagecreatetruecolor(150, 30); /* Create a black image */
        $bgc = imagecolorallocate($im, 255, 255, 255);
        $tc  = imagecolorallocate($im, 0, 0, 0);
        imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
        /* Output an errmsg */
        imagestring($im, 1, 5, 5, "Error loading $imgname", $tc);
    }
    return $im;
}
header("Content-Type: image/jpeg");
$img = LoadJpeg($_GET['file']); 
imagejpeg($img);
?> 

 

 

Hope it helps

 

--MadTechie

 

 

EDIT you may need to use urlencode & urldecode  for passing the URL 4:22am here, i'm off to bed