batch process

I have a future requirement to consecutively page number a pdf document assembled from many individual pdf files. Is there something that runs on FreeBSD that will handle this? I need to be able to specify the location of the page number on the page. In other words 'centre bottom, 1/2" above...

Hi Heres how to extract the audio from a single video file ffmpeg -i infile.mp4 -vn -c:a copy outfile.m4a batch extract audio from video files find -s . -type f -name "*.mp4" -exec sh -c \ 'ffmpeg -i "${0}" -vn -c:a copy "${0%.*}.m4a"' \ "{}" \;