A2ps formats each named file for printing in a postscript printer; if no file is given, a2ps reads from the standard input. The format used is nice and compact: normally two pages on each physical page, borders surrounding pages, headers with useful information (page number, printing date, file name or supplied header), line numbering, etc. This is very useful for making archive listings of programs.
WWW: https://www.gnu.org/software/a2ps/