PHP Image Rotator Script via A List Apart

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PHP Image Rotator Script via A List Apart

I just wanted to post a quick note about a great php image rotator script that I just found on A List Apart. It was one of the most painless scripts I have ever setup. I needed a little script that would rotate images everytime you visited this client’s homepage, I figured I could create a script if needed – but I always Google it first.

After a quick little read through the article, I uploaded the images, place the script in the same directory as the images. Then called the script from the img src tag and voila! It works! Check it out if you are looking for a nice little script!

[php]
<?php

/*

AUTOMATIC IMAGE ROTATOR
Version 2.2 – December 4, 2003
Copyright (c) 2002-2003 Dan P. Benjamin, Automatic, Ltd.
All Rights Reserved.

http://www.hiveware.com/imagerotator.php

http://www.automaticlabs.com/

DISCLAIMER
Automatic, Ltd. makes no representations or warranties about
the suitability of the software, either express or
implied, including but not limited to the implied
warranties of merchantability, fitness for a particular
purpose, or non-infringement. Dan P. Benjamin and Automatic, Ltd.
shall not be liable for any damages suffered by licensee
as a result of using, modifying or distributing this
software or its derivatives.

ABOUT
This PHP script will randomly select an image file from a
folder of images on your webserver. You can then link to it
as you would any standard image file and you’ll see a random
image each time you reload.

When you want to add or remove images from the rotation-pool,
just add or remove them from the image rotation folder.

VERSION CHANGES
Version 1.0
– Release version

Version 1.5
– Tweaked a few boring bugs

Version 2.0
– Complete rewrite from the ground-up
– Made it clearer where to make modifications
– Made it easier to specify/change the rotation-folder
– Made it easier to specify/change supported image types
– Wrote better instructions and info (you’re them reading now)
– Significant speed improvements
– More error checking
– Cleaner code (albeit more PHP-specific)
– Better/faster random number generation and file-type parsing
– Added a feature where the image to display can be specified
– Added a cool feature where, if an error occurs (such as no
images being found in the specified folder) *and* you’re
lucky enough to have the GD libraries compiled into PHP on
your webserver, we generate a replacement "error image" on
the fly.

Version 2.1
– Updated a potential security flaw when value-matching
filenames

Version 2.2
– Updated a few more potential security issues
– Optimized the code a bit.
– Expanded the doc for adding new mime/image types.

Thanks to faithful ALA reader Justin Greer for
lots of good tips and solid code contribution!

INSTRUCTIONS
1. Modify the $folder setting in the configuration section below.
2. Add image types if needed (most users can ignore that part).
3. Upload this file (rotate.php) to your webserver. I recommend
uploading it to the same folder as your images.
4. Link to the file as you would any normal image file, like this:

<img src="http://example.com/rotate.php">

5. You can also specify the image to display like this:

<img src="http://example.com/rotate.php?img=gorilla.jpg">

This would specify that an image named "gorilla.jpg" located
in the image-rotation folder should be displayed.

That’s it, you’re done.

*/

/* ————————- CONFIGURATION ———————–

Set $folder to the full path to the location of your images.
For example: $folder = ‘/user/me/example.com/images/’;
If the rotate.php file will be in the same folder as your
images then you should leave it set to $folder = ‘.’;

*/

$folder = ‘.’;

/*

Most users can safely ignore this part. If you’re a programmer,
keep reading, if not, you’re done. Go get some coffee.

If you’d like to enable additional image types other than
gif, jpg, and png, add a duplicate line to the section below
for the new image type.

Add the new file-type, single-quoted, inside brackets.

Add the mime-type to be sent to the browser, also single-quoted,
after the equal sign.

For example:

PDF Files:

$extList[‘pdf’] = ‘application/pdf’;

CSS Files:

$extList[‘css’] = ‘text/css’;

You can even serve up random HTML files:

$extList[‘html’] = ‘text/html’;
$extList[‘htm’] = ‘text/html’;

Just be sure your mime-type definition is correct!

*/

$extList = array();
$extList[‘gif’] = ‘image/gif’;
$extList[‘jpg’] = ‘image/jpeg’;
$extList[‘jpeg’] = ‘image/jpeg’;
$extList[‘png’] = ‘image/png’;

// You don’t need to edit anything after this point.

// ——————— END CONFIGURATION ———————–

$img = null;

if (substr($folder,-1) != ‘/’) {
$folder = $folder.’/’;
}

if (isset($_GET[‘img’])) {
$imageInfo = pathinfo($_GET[‘img’]);
if (
isset( $extList[ strtolower( $imageInfo[‘extension’] ) ] ) &&
file_exists( $folder.$imageInfo[‘basename’] )
) {
$img = $folder.$imageInfo[‘basename’];
}
} else {
$fileList = array();
$handle = opendir($folder);
while ( false !== ( $file = readdir($handle) ) ) {
$file_info = pathinfo($file);
if (
isset( $extList[ strtolower( $file_info[‘extension’] ) ] )
) {
$fileList[] = $file;
}
}
closedir($handle);

if (count($fileList) > 0) {
$imageNumber = time() % count($fileList);
$img = $folder.$fileList[$imageNumber];
}
}

if ($img!=null) {
$imageInfo = pathinfo($img);
$contentType = ‘Content-type: ‘.$extList[ $imageInfo[‘extension’] ];
header ($contentType);
readfile($img);
} else {
if ( function_exists(‘imagecreate’) ) {
header ("Content-type: image/png");
$im = @imagecreate (100, 100)
or die ("Cannot initialize new GD image stream");
$background_color = imagecolorallocate ($im, 255, 255, 255);
$text_color = imagecolorallocate ($im, 0,0,0);
imagestring ($im, 2, 5, 5, "IMAGE ERROR", $text_color);
imagepng ($im);
imagedestroy($im);
}
}

?>
[/php]

Thanks A List Apart!

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