Create Unique Image Names

Question

What\'s a good way to create a unique name for an image that my user is uploading?

I don\'t want to have any duplicates so something like MD5($filename) isn\'t suita

Answer 1

lol there are around 63340000000000000000000000000000000000000000000000 possibility's that md5 can produce plus you could use just tobe on the safe side

$newfilename = md5(time().'image');
if(file_exists('./images/'.$newfilename)){
    $newfilename = md5(time().$newfilename);
}
//uploadimage