fstatat (GNU Gnulib)

Gnulib module: fstatat

Portability problems fixed by Gnulib:

This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
On platforms where off_t is a 32-bit type, fstatat may not correctly report the size of files or block devices larger than 2 GB. See Large File Support.
On some platforms, fstatat(fd,"file/",buf,flag) succeeds instead of failing with ENOTDIR. Solaris 9.
For symlinks, when the argument ends in a slash, some platforms don’t dereference the argument: Solaris 9.
On macOS 12.6, when this function yields a timestamp with a nonpositive tv_sec value, tv_nsec might be in the range -999999999..-1, representing a negative nanoseconds offset from tv_sec. Solaris 11.4 is similar, except that tv_sec might also be -1000000000.

Portability problems not fixed by Gnulib:

This function does not fail when the second argument is an empty string on some platforms, even when AT_EMPTY_PATH is not used: glibc 2.7, Linux 2.6.38.
This function sets st_ino only to the low-order 32 bits of the inode number of a socket or pipe, which thus can disagree with the st_ino obtained by fstat: macOS 14.
See sys/stat.h, for general portability problems with struct stat.