Name
symlink, symlinkat — make a new name for a file
Synopsis
#include <unistd.h>
int
symlink( |
const char *target, |
const char *linkpath); |
#include <fcntl.h> /* Definition of AT_* constants */ #include <unistd.h>
int
symlinkat( |
const char *target, |
| int newdirfd, | |
const char *linkpath); |
![[Note]](../stylesheet/note.png) |
Note | ||||||||
|---|---|---|---|---|---|---|---|---|---|
|
DESCRIPTION
symlink() creates a symbolic
link named linkpath
which contains the string target.
Symbolic links are interpreted at run time as if the contents of the link had been substituted into the path being followed to find a file or directory.
Symbolic links may contain .. path components, which (if used at the
start of the link) refer to the parent directories of that in
which the link resides.
A symbolic link (also known as a soft link) may point to an existing file or to a nonexistent one; the latter case is known as a dangling link.
The permissions of a symbolic link are irrelevant; the
ownership is ignored when following the link, but is checked
when removal or renaming of the link is requested and the
link is in a directory with the sticky bit (S_ISVTX) set.
If linkpath
exists, it will not
be overwritten.
symlinkat()
The symlinkat() system
call operates in exactly the same way as symlink(), except for the differences
described here.
If the pathname given in linkpath is relative, then it
is interpreted relative to the directory referred to by the
file descriptor newdirfd (rather than
relative to the current working directory of the calling
process, as is done by symlink() for a relative pathname).
If linkpath is
relative and newdirfd is the special value
AT_FDCWD, then linkpath is interpreted
relative to the current working directory of the calling
process (like symlink()).
If linkpath is
absolute, then newdirfd is ignored.
RETURN VALUE
On success, zero is returned. On error, −1 is
returned, and errno is set
appropriately.
ERRORS
- EACCES
-
Write access to the directory containing
linkpathis denied, or one of the directories in the path prefix oflinkpathdid not allow search permission. (See also path_resolution(7).) - EDQUOT
-
The user's quota of resources on the filesystem has been exhausted. The resources could be inodes or disk blocks, depending on the filesystem implementation.
- EEXIST
-
linkpathalready exists. - EFAULT
-
targetorlinkpathpoints outside your accessible address space. - EIO
-
An I/O error occurred.
- ELOOP
-
Too many symbolic links were encountered in resolving
linkpath. - ENAMETOOLONG
-
targetorlinkpathwas too long. - ENOENT
-
A directory component in
linkpathdoes not exist or is a dangling symbolic link, ortargetorlinkpathis an empty string. - ENOMEM
-
Insufficient kernel memory was available.
- ENOSPC
-
The device containing the file has no room for the new directory entry.
- ENOTDIR
-
A component used as a directory in
linkpathis not, in fact, a directory. - EPERM
-
The filesystem containing
linkpathdoes not support the creation of symbolic links. - EROFS
-
linkpathis on a read-only filesystem.
The following additional errors can occur for symlinkat():
- EBADF
-
newdirfdis not a valid file descriptor. - ENOENT
-
linkpathis a relative pathname andnewdirfdrefers to a directory that has been deleted. - ENOTDIR
-
linkpathis relative andnewdirfdis a file descriptor referring to a file other than a directory.
VERSIONS
symlinkat() was added to
Linux in kernel 2.6.16; library support was added to glibc in
version 2.4.
NOTES
No checking of target is done.
Deleting the name referred to by a symbolic link will actually delete the file (unless it also has other hard links). If this behavior is not desired, use link(2).
Glibc notes
On older kernels where symlinkat() is unavailable, the glibc
wrapper function falls back to the use of symlink(2). When
linkpath is a
relative pathname, glibc constructs a pathname based on the
symbolic link in /proc/self/fd that corresponds to the
newdirfd
argument.
SEE ALSO
ln(1), lchown(2), link(2), lstat(2), open(2), readlink(2), rename(2), unlink(2), path_resolution(7), symlink(7)
COLOPHON
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
This manpage is Copyright (C) 1992 Drew Eckhardt; and Copyright (C) 1993 Michael Haardt, Ian Jackson. and Copyright (C) 2006, 2014 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 Modified 1993-07-24 by Rik Faith Modified 1996-04-26 by Nick Duffek <nsdbbc.com> Modified 1996-11-06 by Eric S. Raymond <esrthyrsus.com> Modified 1997-01-31 by Eric S. Raymond <esrthyrsus.com> Modified 2004-06-23 by Michael Kerrisk <mtk.manpagesgmail.com> |