This thread my be of help: How to concatenate the contents of two files?

0. open file for input

1. loop through files (use foreach ?)

2. open file in binary mode (see documentation for 'open' command, and 'binmode') perldoc -f open
ex:   open (FH, "<:raw", $myfile) or die "Oops: $!"

3. read x number of bytes from file, using 'read' command (perldoc -f read)

4. write what you have read to your 'new' file

5. continue writing until end-of-file, loop for next input file.