Name
readlinkat — read value of a symbolic link relative to a directory file descriptor
Synopsis
#include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h>
int
readlinkat( |
int dirfd, |
| const char *pathname, | |
| char *buf, | |
size_t bufsiz); |
![[Note]](../stylesheet/note.png) |
Note | |||||
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DESCRIPTION
The readlinkat() system call
operates in exactly the same way as readlink(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 readlink(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 readlink(2)).
If pathname is
absolute, then dirfd
is ignored.
Since Linux 2.6.39, pathname can be an empty
string, 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.
RETURN VALUE
On success, readlinkat()
returns the number of bytes placed in buf. On error, −1 is
returned and errno is set to
indicate the error.
ERRORS
The same errors that occur for readlink(2) can also occur
for readlinkat(). The following
additional errors can occur for readlinkat():
- EBADF
-
dirfdis not a valid file descriptor. - ENOTDIR
-
pathnameis relative anddirfdis a file descriptor referring to a file other than a directory.
VERSIONS
readlinkat() was added to
Linux in kernel 2.6.16; library support was added to glibc in
version 2.4.
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/.
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This manpage is Copyright (C) 2006, Michael Kerrisk %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END |