On Tue, Feb 22, 2005 at 04:45:42PM +0100, Sam Lauber wrote: > [ James Youngman wrote: ] > > > You're right, I hadn't thought of that. According to the POSIX > > standard (IEEE Std 1003.1, 2003 Edition), > > > > | The 'string' argument should point to a string of the form " name= > > | value ". The putenv() function shall make the value of the > > | environment variable 'name' equal to 'value' by altering an > > | existing variable or creating a new one. In either case, the > > | string pointed to by 'string' shall become part of the > > | environment, so altering the string shall change the environment. > > According to the DJGPP C Library manual, it seems to say > things are the other way around. It says that the string > is _supposed_ to be copied.
Yes, but the DJGPP library intends to be a C library for DOS systems, and does not intend, as far as I know, to provide a POSIX compilation environment. Therefore there is no need for it to comply with POSIX and so it can do whatever it wants (putenv is not part of the standard C library). > But if there's at least one C library or compiler that's > not standards compliant, someone has to cater to them or > risk that construct being nonportable without anyone > knowing it, everyone using it, only to break on a platform > like DJGPP. (I can justify that it's the job of Autoconf > to track down those things.). It's an open question as to whether Autoconf should replace an OS-specific putenv() function just because it doesn't fully comply with POSIX. > P.S. Nowadays, I've noticed a lot of free software is > impolite to DOS systems. Well, the semantics of environment segments in DOS are baroque. See http://excession.spiral-arm.org/jay/programs/envset.c for an example of the full horror of these things. Regards, James.
