10.69.21 faccessat ¶
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9799919799/functions/faccessat.html
Gnulib module: faccessat
Portability problems fixed by Gnulib:
- This function is missing on some platforms:
glibc 2.3.6, macOS 10.9, FreeBSD 7.4, NetBSD 6.1.5, OpenBSD 4.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
- On some platforms,
faccessat (dfd, "file/", amode, flag)
succeeds instead of failing when file is not a directory.
macOS 14.
Portability problems not fixed by Gnulib:
- The replacement does not always take ACLs into account.
- The replacement is not safe to be used in libraries.
- The replacement is not multithread-safe.
- The replacement does not support the
AT_SYMLINK_NOFOLLOW flag,
which is supported by GNU faccessat.
- On some platforms,
faccessat can mishandle AT_EACCESS
after a process starts as root and then becomes non-root:
GNU/Linux with glibc 2.32.
Other problems of this function:
- There is an inherent race between calling this function and performing
some action based on the results; you should think twice before trusting
this function, especially in a set-uid or set-gid program.