On Sat, Jul 23, 2022 at 9:21 AM Rob Pike wrote: Very odd. I thought so too, but the 8th Edition manual says pr -n > prints in n columns, I'm almost certain that -n here means that -2 is 2 columns, -3 columns, etc., and that there is no actual -n switch. In Posix as well as more modern man pages this is spelled -COLUMNS: see man.cat-v.org. > while the 9th and 10th say it numbers the lines. > I think this may have come from BSD; it is now part of Posix.