What is the best way to determine whether or not a file is an image in PHP?

Question

I have a sever which people can upload files to. The problem is that some of the filenames are mangled (dont have any extension) and so I cannot immediately determine file type.

Answer 1

You can use getimagesize It does not require the GD image library and it returns same information about image type. http://it2.php.net/manual/en/function.getimagesize.php