On Thu, 8 Jul 2004, Christopher Faylor wrote: > On Thu, Jul 08, 2004 at 10:25:09AM -0400, Igor Pechtchanski wrote: > >On Thu, 8 Jul 2004, Corinna Vinschen wrote: > > > >> On Jul 8 11:49, Daniel Lungu wrote: > >> > Feel like bash tcsh on Cygwin mess up with negative exit status > >> > from a cl compiled .exe ^^^^^^^^^^^^^^^^ > >> The answer is "don't do that". Use positive values in the range from > >> 0 to 255. See > >> http://www.opengroup.org/onlinepubs/009695399/functions/exit.html > > > >Actually, it looks like another buglet in Cygwin. The code in > >spawn_guts() in spawn.cc (line 847 in CVS HEAD) simply binary-ORs the > >exitcode value returned by GetExitCodeProcess with the "res" variable. > >However, the "res" variable is also used to carry some flags, and a > >negative exitcode, being a full DWORD, accidentally sets those, so all > >sorts of havoc can potentially occur (and I'm surprised that all that > >happens is the wrong exit code). > > This is not a bug. A cygwin program can't set a negative exit code. > Only the lower order 16 bits are used. This is enforced by _exit. > > If someone uses ExitProcess in a cygwin program, then well, err... > cgf
You would be right if spawn() could only be used for Cygwin programs. Unfortunately, it can also be used for non-Cygwin programs (as shown by the underlined phrase above) which don't operate under the above restriction. So, I'd say that binary-ANDing the exitcode value with 0xFF (or 0xFFFF if you want 16 bits) is a healthy precaution. It will certainly do no harm, and it will make absolutely sure that the other flags (e.g., EXIT_REPARENTING) are never tread upon. Igor -- http://cs.nyu.edu/~pechtcha/ |\ _,,,---,,_ [EMAIL PROTECTED] ZZZzz /,`.-'`' -. ;-;;,_ [EMAIL PROTECTED] |,4- ) )-,_. ,\ ( `'-' Igor Pechtchanski, Ph.D. '---''(_/--' `-'\_) fL a.k.a JaguaR-R-R-r-r-r-.-.-. Meow! "I have since come to realize that being between your mentor and his route to the bathroom is a major career booster." -- Patrick Naughton -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/