On Sat, Aug 09, 2014 at 11:32:02AM -0400, Noel Chiappa wrote: V4 to V6 had this limit of 512 bytes. It's documented in exec(2), http://minnie.tuhs.org/cgi-bin/utree.pl?file=V4/man/man2/exec.2 http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/man/man2/exec.2 and the code is in sys1.c, e.g. E2BIG, http://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/sys/ken/sys1.c V7 then also implemented NCARGS (sys/param.h). I can't read assembler and tried to find the limit in a running V1 http://code.google.com/p/unix-jun72/ with a script which just echoes its arguments, and found - command line (script or interactive) not longer than 255 characters - single argument not longer than about 82 characters (how this might have come off?) Exceeding this lead to data corruption or kernel crash. Early exec(2) reads V1: The arguments are placed as high as possible incore: just below 60000(8). V3: The arguments are placed as high as possible in core: just below 57000(8). and I wonder if it's possible to determine limits from this. Sven (I was interested in ARG_MAX in general and collected my experiences on http://www.in-ulm.de/~mascheck/various/argmax/)