POSIX and ISC 2.2.x -- how many people are using this?

[Eric Gisin]

In article <1991Apr16.235122.26807 at scuzzy.in-berlin.de> src at scuzzy.in-berlin.de (Heiko Blume) writes:
   real strange, i have compiled quite a lot with something like

   gcc -D_POSIX_SOURCE -DPOSIX -o bla bla.c -lcposix

   for instance, bash-1.05, tcsh-5.20.02, elm-2.3#11 and lots more.
   i never tried the stuff mentioned in cc(1) like setenv OSTYPE POSIX,
   since it works for me without that (and my hacked bash definitely
   is full of posix job control etc).

   never ever have i seen a panic whatsoever. i run 2.2.1
   with the security fix on a informtech 386/33 board, aha-1542a,
   lotsa disks, hercules card.

There is a big difference between compiling with "cc -Xp" or "OSTYPE=POSIX cc",
and just linking with -lcposix. Both give you access to the extra POSIX.1
functions like job control, but the former gives you a different run-time
start-up. This start-up does a __setostype(_OS_POSIX), which changes
the behaviour of some systems calls. For example, you get supplementry group
permissions, path components longer that 14 characters give ENAMETOOLONG,
and various other things (like crashes).