faccessat

faccessat - check user's permissions of a file relative to a  directory file descriptor

#define _ATFILE_SOURCE
#include <fcntl.h>
#include <unistd.h>
 I int faccessat(int  dirfd , const char * pathname , int  \
mode ", int " flags );

The R faccessat () system call operates in exactly the same way as access(2), except for the differences described in this manual page. If the pathname given in pathname is relative, then it is interpreted relative to the directory referred to by the file descriptor R dirfd (rather than relative to the current working directory of the calling process, as is done by access(2) for a relative pathname). If pathname is relative and dirfd is the special value R AT_FDCWD , then pathname is interpreted relative to the current working directory of the calling process (like access(2)). If R pathname is absolute, then dirfd is ignored. flags is constructed by ORing together zero or more of the following values:

AT_EACCESS

AT_SYMLINK_NOFOLLOW

On success, (all requested permissions granted) R faccessat () returns 0. On error, -1 is returned and errno is set to indicate the error.

The same errors that occur for access(2) can also occur for R faccessat (). The following additional errors can occur for R faccessat ():

EBADF

EINVAL

ENOTDIR

R faccessat () was added to Linux in kernel 2.6.16.

This system call is non-standard but is proposed for inclusion in a future revision of POSIX.1.

See openat(2) for an explanation of the need for R faccessat ().

Glibc Notes

The AT_EACCESS and AT_SYMLINK_NOFOLLOW flags are actually implemented within the glibc wrapper function for R faccessat (). If either of these flags are specified, then the wrapper function employs fstatat(2) to determine access permissions.

access(2), openat(2), euidaccess(3), credentials(7), path_resolution(7)