A while back I had a series of PDF documents that were in chapter forms. If my memory serves me correctly, it was the teacher book which included answers in college. I didn’t want 20 pdfs, I wanted only one. Here’s how to combine them all on the command line with ghost script installed:
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=book.pdf ch00.pdf ch01.pdf ch02.pdf ch03.pdf ch04.pdf ch05.pdf ch06.pdf ch07.pdf ch08.pdf ch09.pdf ch10.pdf ch11.pdf ch12.pdf ch13.pdf ch14.pdf ch15.pdf ch16.pdf index.pdf biblio.pdf
That combines chapters 0-16, then index and bibliography (in that order) into book.pdf!
