Allow certain image formats not working

Question

I'm trying to allow certain formats get uploaded to my website. I'm using the call getimagesize() to identify the image type (which is returned as the third parameter). I followed this guide to perform that. Here's the code:

$img=$_FILES['img'];
$info = getimagesize($img);

if (($info[2] !== IMAGETYPE_GIF) && ($info[2] !== IMAGETYPE_JPEG) && ($info[2] !== IMAGETYPE_PNG)) {
    echo json_encode(array('bad' => 'Bad Format'));
    exit();
} else {
    echo json_encode(array('good' => 'Good format'));
    exit();
}

No matter what file format I try uploading, I always get the else statement. echo json_encode(array('good' => 'Good format'));

Why is that happening, and how can I fix it?

Answer 1

it will always be false since you are using the && operator.

$img=$_FILES['img'];
$accepted = array('image/jpeg','image/png','image/gif');

if (in_array($img['type'],$accepted)) {
    echo json_encode(array('bad' => 'Good Format'));
    exit();
} else {
    echo json_encode(array('good' => 'Bad format'));
    exit();
}

use the || or or to get what you want.

Doing it with getimagesize()

$img=$_FILES['img'];
$info = getimagesize($img['tmp_name']); //pass the file

Change your condition to || (or)

if (($info[2] === IMAGETYPE_GIF) || ($info[2] === IMAGETYPE_JPEG) || ($info[2] === IMAGETYPE_PNG)) {
    echo json_encode(array('bad' => 'Good Format'));
    exit();
} else {
    echo json_encode(array('good' => 'Bad format'));
    exit();
}