php - How to combine several file parts (Blobs) to the original file after ajax upload with unix cat command? -

i created uploader script can upload large files because splits blobs. figured out using php's fopen , fwrite won't work putting parts again (maybe memory thing).

i figured out there unix command cat put (http://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-cat-command-examples/)

but question is: how can select fileparts , put in 1 php exec command?

i think syntax kinda have no idea how select parts:

exec('cat "'.$all_my_parts.'" >> "' . $original_filename.'"');