PHP: Get file extension not working on uploads to S3

Question

I am using the Amazon S3 API to upload files and I am changing the name of the file each time I upload.

So for example:

Dog.png > 3Sf5f.png

Now I got

Answer 1

i am using this in my websites (and works fine for years):

$file = 'yourOriginalfile.png';

//get the file extension
$fileExt = substr(strrchr($file, '.'), 1);

//create a random name and add the original extension
$fileUniqueName = md5(uniqid(mktime())) . '.' . $fileExt;

rename($file,$fileUniqueName); 

your function generates too short filenames (5 characters), this way creates longer filenames, avoiding to collide the file names.

example output: aff5a25e84311485d4eedea7e5f24a4f.png