int openat(int dirfd, const char *pathname, int flags);
int openat(int dirfd, const char *pathname, int flags, mode_t mode);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
The openat() system call operates in exactly the same way as open(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 open(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 open(2)).
If pathname is absolute, then dirfd is ignored.
On success, openat() returns a new file descriptor. On error, -1 is
returned and errno is set to indicate the error.
The same errors that occur for open(2) can also occur for openat().
The following additional errors can occur for openat():
EBADF dirfd is not a valid file descriptor.
pathname is relative and dirfd is a file descriptor referring to
a file other than a directory.
openat() was added to Linux in kernel 2.6.16; library support was added
to glibc in version 2.4.
POSIX.1-2008. A similar system call exists on Solaris.
openat() and other similar system calls suffixed "at" are supported for
use of /proc/self/fd/dirfd, but less efficiently.)
faccessat(2), fchmodat(2), fchownat(2), fstatat(2), futimesat(2),
linkat(2), mkdirat(2), mknodat(2), open(2), readlinkat(2), renameat(2),
symlinkat(2), unlinkat(2), utimensat(2), mkfifoat(3), path_resolu-
This page is part of release 3.54 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 2012-05-04 OPENAT(2)
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