note graff According to the "Useful tips" section (on page 7) of the [http://www.jpeg.org/public/jfif.pdf|official specs], you should be able to read the first 11 bytes of the file and match this pattern: <c> /\xff.\xff...JFIF\x0/ </c> Based on looking at a small number of "*.jpg" files I happen to have uploaded from a camera (via "iPhoto", which may have been involved in "updating" some of those pictures after the upload), I would actually change that to: <c> /\xff.\xff...(?:JFIF|Exif)\x0/ </c> And apparently, you might expect "JFXX" as well. But frankly, I'd be content to trust the file name, and so would focus on the first reply above. <P> UPDATE: The above assumes that the file is being read in <c>:raw</c> mode (what we commonly understand as the default behavior of doing <c>binmode FH</c>). Also, I agree with what [afoken] says below: use a module to validate jpeg files, in case there is any doubt about their validity. 779295 779295