Fast md5 file hashing in php

What's the fastest way?

[Garfield]

Hi folks,

I need to hash files with md5. Filesize is between 3 and 20 MB. Currently I use file_get_contents to load the entire file into a string and then hash it. This is not really slow, but auite memory consuming since files have to be read entirely to memory.

Is there a better way to do hashing in php? It has to be fast, but a little less memory consuming would be great. Would it be possible to use the UNIX md5sum command to hash the files and then parse the output?

Thanks in advance!

[Forse]

well u could do:

exec('md5sum '.$filename);

but I am not sure if that's a better way