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 one or more of the following flags ORed:

AT_EMPTY_PATH (since Linux 2.6.39)
    If pathname is an empty string, operate on the file referred to by in which case the call operates on the file referred to by dirfd (which may have been obtained using the open(2) O_PATH flag). In this case, dirfd can refer to any type of file, not just a directory.

AT_NO_AUTOMOUNT (since Linux 2.6.38)
    Don't automount the terminal ("basename") component of pathname if it is a directory that is an automount point. This allows the caller to gather attributes of an automount point (rather than the location it would mount). This flag can be used in tools that scan directories to prevent mass-automounting of a directory of automount points. The AT_NO_AUTOMOUNT flag has no effect if the mount point has already been mounted over.

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; library support was added to glibc in version 2.4.

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

NOTES
See openat(2) for an explanation of the need for fstatat(). The underlying system call employed by the glibc fstatat() wrapper function is actually called fstatat64().

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

COLOPHON
This page is part of release 3.53 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/.