Btukfyl

i need your suggestions for checking image file. If a user will upload any file with changed extension type like (jpg,jpeg,bmp,png) how do we figure out that in PHP?

I will use mime_content_type is exists. Else execute linux command of file -i -b on the file to get the answer.

Consider function as following:

function getFileType($file_name) {

        if(! function_exists('mime_content_type')) {

            $isUnix = strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN' && DIRECTORY_SEPARATOR === '/';



            // check whether operating system is that of a UNIX type.

            if ($isUnix) {

                $type = null;

                exec('file -i -b ' . realpath($file_name), $type);

                $parts = @ explode(";", $type[0]); // can be of format text/plain;  charset=us-ascii 

                return trim($parts[0]);

            }



            // the file program/command does not exist on Windows.

            else {

                return null;

            }

        } else {

            return mime_content_type($file_name);

        }

    }

You can also use finfo-file is you prefer.

You can check for the filetype with 'filetype()' in PHP: PHP filetype