Solved

How can I cache a fetched image from a network and output it on the webserver?

Posted on 2003-11-20
3
241 Views
Last Modified: 2007-12-29
I have a webcam set up on a computer on our University network.  This computer is visible to all other uni computers, including the webserver we use, but not to the outside world.  Currently the webcam is serving an image on port 80 of it's own computer.  I can link to this with an image tag in a file on the webserver and the pic will display when a campus computer requests it, but obviously not when the request is made from the outside world.  Therefore I need some PHP to fetch the image from the webcam server, cache it, and output it on the web page so that all can see the image.  Any ideas how to do this?
0
Comment
Question by:djpeanut
3 Comments
 
LVL 13

Accepted Solution

by:
lozloz earned 200 total points
ID: 9788520
hi,

script by a friend of mine seems to suit your needs:

<?

// Sam Overton 2002

$filename = "wcamimg.jpg";                  // file to cache in
$altfile = "images/unavail.gif";                  // alt image to use (if cam is down)
$update_time = 3;                        // fetch new image if last update was more than x seconds
$url = "http://server.com:80/";                  // url to fetch the image from
$maximgsize = 300*1024;                  // maximum amount of data it will read

// check if this is the first time we run the script (evar!)
$makenew = FALSE;
if(!file_exists($filename))
{
      touch($filename);
      $makenew = TRUE;
}


//get file modified time
$timestamp = filemtime($filename);
$thetime = time();
if($thetime - $timestamp > $update_time || $makenew)
{
      // we need to fetch a new copy
      $newfile = @fopen($url,"rb");
      if(!$newfile)
      {
            // couldnt get a new copy!!!
            // use the alt image (webcam unavailable or soemthing)
            $newfile = fopen($altfile,"rb");
      }

      // read in our data from the remote location
      $buffer = fread($newfile,$maximgsize);
      fclose($newfile);

      // store it locally
      $file = fopen($filename,"wb");
      fwrite($file,$buffer);
      fclose($file);

      // spit it out
      header("Content-type: image/jpeg");
      print($buffer);
}
else
{
      // local copy is recent enough so read it in
      $file = fopen($filename,"rb");
      $buffer = fread($file,filesize($filename));
      fclose($file);

      // spit, dont swallow :[
      header("Content-type: image/jpeg");
      print($buffer);
}
?>

then you can just use <img src="webcam.php" border="0"> or something in any other page to get the image

loz
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Author Note: Since this E-E article was originally written, years ago, formal testing has come into common use in the world of PHP.  PHPUnit (http://en.wikipedia.org/wiki/PHPUnit) and similar technologies have enjoyed wide adoption, making it possib…
Nothing in an HTTP request can be trusted, including HTTP headers and form data.  A form token is a tool that can be used to guard against request forgeries (CSRF).  This article shows an improved approach to form tokens, making it more difficult to…
The viewer will learn how to dynamically set the form action using jQuery.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question