faccessat(2) [linux man page]

FACCESSAT(2)						     Linux Programmer's Manual						      FACCESSAT(2)

NAME

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

SYNOPSIS

       #include <fcntl.h> /* Definition of AT_* constants */
       #include <unistd.h>

       int faccessat(int dirfd, const char *pathname, int mode, int flags);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       faccessat():
	   Since glibc 2.10:
	       _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
	   Before glibc 2.10:
	       _ATFILE_SOURCE

DESCRIPTION

       The 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 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 AT_FDCWD, then pathname is interpreted relative to the current working directory	of
       the calling process (like access(2)).

       If pathname is absolute, then dirfd is ignored.

       flags is constructed by ORing together zero or more of the following values:

       AT_EACCESS
	      Perform access checks using the effective user and group IDs.  By default, faccessat() uses the real IDs (like access(2)).

       AT_SYMLINK_NOFOLLOW
	      If pathname is a symbolic link, do not dereference it: instead return information about the link itself.

RETURN VALUE

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

ERRORS

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

       EBADF  dirfd is not a valid file descriptor.

       EINVAL Invalid flag specified in flags.

       ENOTDIR
	      pathname is relative and dirfd is a file descriptor referring to a file other than a directory.

VERSIONS

       faccessat() was added to Linux in kernel 2.6.16.

CONFORMING TO

       POSIX.1-2008.

NOTES

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

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

SEE ALSO

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

COLOPHON

       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2009-12-13							      FACCESSAT(2)

Check Out this Related Man Page

FSTATAT(2)						     Linux Programmer's Manual							FSTATAT(2)

NAME

       fstatat - get file status relative to a directory file descriptor

SYNOPSIS

       #include <fcntl.h> /* Definition of AT_* constants */
       #include <sys/stat.h>

       int fstatat(int dirfd, const char *pathname, struct stat *buf,
		   int flags);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       fstatat():
       Since glibc 2.10: _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
       Before glibc 2.10: _ATFILE_SOURCE

DESCRIPTION

       The fstatat() system call operates in exactly the same way as stat(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 dirfd
       (rather than relative to the current working directory of the calling process, as is done by stat(2) for a relative pathname).

       If pathname is relative and dirfd is the special value AT_FDCWD, then pathname is interpreted relative to the current working directory	of
       the calling process (like stat(2)).

       If pathname is absolute, then dirfd is ignored.

       flags can either be 0, or include the following flag:

       AT_SYMLINK_NOFOLLOW
	      If  pathname  is	a  symbolic  link,  do	not  dereference it: instead return information about the link itself, like lstat(2).  (By
	      default, fstatat() dereferences symbolic links, like stat(2).)

RETURN VALUE

       On success, fstatat() returns 0.  On error, -1 is returned and errno is set to indicate the error.

ERRORS

       The same errors that occur for stat(2) can also occur for fstatat().  The following additional errors can occur for fstatat():

       EBADF  dirfd is not a valid file descriptor.

       EINVAL Invalid flag specified in flags.

       ENOTDIR
	      pathname is relative and dirfd is a file descriptor referring to a file other than a directory.

VERSIONS

       fstatat() was added to Linux in kernel 2.6.16.

CONFORMING TO

       POSIX.1-2008.  A similar system call exists on Solaris.

NOTES

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

SEE ALSO

       openat(2), stat(2), path_resolution(7), symlink(7)

COLOPHON

       This page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2009-12-13								FSTATAT(2)

Linux and UNIX Man Pages

faccessat(2) [linux man page]

Check Out this Related Man Page