On Oct 16, 2007, at 21:40 , Richard A. O'Keefe wrote:
F_GETFD and F_SETFD are the things to look for; FD_CLOEXEC is a fancy way of saying 1 in historic UNIXes. The OSF/1 /usr/include/sys/ fcntl.h says that FD_CLOEXEC is "POSIX REQUIRED". This facility is most certainly part of the Single Unix Specification. The MacOS 10.4 manual page for fcntl() doesn't mention FD_CLOEXEC, but it *does* mention F_GETFD and F_SETFD and identifies the close-on-execute flag as being the "low-order bit" of that flags word, so what may possibly be missing from some editions of POSIX is the *name* FD_CLOEXEC but not the facility (F_SETFD) or the value (1).
I could dig for official confirmation, but this is my understanding of both POSIX and SUS, and portable C programs generally #define FD_CLOEXEC to 1 if it doesn't already exist, since the value *is* standard even though the name is not. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH