Having trouble with Custom Function "isImage"

Orc · 12-20-2007, 01:52 AM

PHP Code:


			
<?php

 function isImage($handler) {
    if(file_exists($handler)) {
        $handler == $handler.".JPG";
        $handler == $handler.".PNG";
        $handler == $handler.".GIF";
        $handler == $handler.".BMP";
 }
}

$handler = "test.bmp";

 if(isImage($handler)) {
     echo "$handler is in fact, an Image!";
} else 
   echo "$handler is not an Image!";

   

?>

It outputs $handler is not an Image when really it is!

What is the problem here!

One more thing, is it case sensitive?

Andrew · 12-20-2007, 02:15 AM

What are you trying to accomplish with the following?

PHP Code:


			
$handler == $handler.".JPG";
$handler == $handler.".PNG";
$handler == $handler.".GIF";
$handler == $handler.".BMP";

If you are trying to do what I think you are doing, this should suffice.

PHP Code:


			
function isImage($handler) {
    /* Make the string all lowercase */
    $handler = strtolower($handler);
    /* Get the extension */
    $extension = explode('.', $handler);
    $extension = array_splice($extension, -1, 1);
    /* Check if filetype is allowed */
    if ($extension[0] == 'jpg' || $extension[0] == 'png' || $extension[0] == 'gif' || $extension[0] == 'bmp') {
        /* Check if the file exists */
        if (file_exists($handler)) {
            echo 'File exists.';
        } else {
            echo 'File does not exist.';
        }
    } else {
        echo 'Unknown file type.';
    }
}

Orc · 12-20-2007, 02:34 AM

Quote:

Originally Posted by Andrew

What are you trying to accomplish with the following?

PHP Code:


			
$handler == $handler.".JPG";

$handler == $handler.".PNG";

$handler == $handler.".GIF";

$handler == $handler.".BMP";

If you are trying to do what I think you are doing, this should suffice.

PHP Code:


			
function isImage($handler) {

    /* Make the string all lowercase */

    $handler = strtolower($handler);

    /* Get the extension */

    $extension = explode('.', $handler);

    $extension = array_splice($extension, -1, 1);

    /* Check if filetype is allowed */

    if ($extension[0] == 'jpg' || $extension[0] == 'png' || $extension[0] == 'gif' || $extension[0] == 'bmp') {

        /* Check if the file exists */

        if (file_exists($handler)) {

            echo 'File exists.';

        } else {

            echo 'File does not exist.';

        }

    } else {

        echo 'Unknown file type.';

    }

}

Thanks, I'll try it! :D

deflated · 12-29-2007, 05:18 PM

The extension of a file does not prove that it contains an image. Even better is to determine the MIME type or to use exif_imagetype() and check if it has returned false.

Alan @ CIT · 12-30-2007, 12:19 AM

For getting the MIME type, I would suggest using getimagesize():

PHP Code:


			
$myImage = getimagesize('images/pic.gif');

echo $myImage['mime'];



// would echo the mime type for the given image

Alan