euidaccess (GNU Gnulib)

Documentation:
man euidaccess

Gnulib module: euidaccess

Portability problems fixed by Gnulib:

This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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.
This function does not have an option for not following symbolic links (like stat versus lstat). If you need this option, use the Gnulib module faccessat with the AT_EACCESS flag.
On Solaris, for the root user, any file is X_OK even if the file does not have the x permission bit set.