Manual page for link(2)
link - link to a file
SYNOPSIS
#include <unistd.h>
int link(const char *existing,
const char *new);
DESCRIPTION
link()
creates a new link (directory entry) for the existing file and
increments its link count by one.
existing
points to a
path name
naming an existing file.
new
points to a
path name
naming the new directory entry to be created.
To create hard links, both files must be on the same file system.
Both the old and the new link share equal access and rights to
the underlying object.
The super-user may make multiple links to a directory.
Unless the caller is the super-user, the file named by
existing
must not be a directory.
Upon successful completion,
link()
marks for update the st_ctime
field of the file. Also, the st_ctime and st_mtime fields of
the directory that contains the new entry are marked for update.
RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, a value of -1 is returned and
errno
is set to indicate the error.
ERRORS
link()
will fail and no link will be created if one or more of the following
are true:
- EACCES
-
A component of either path prefix denies search permission.
The requested link requires writing in a directory
with a mode that denies write permission.
- EDQUOT
-
The directory where the entry for the new link is being placed
cannot be extended because the user's quota of disk blocks
on that file system has been exhausted.
- EEXIST
-
The link named by
new
exists.
- EFAULT
-
existing
or
new
points to an illegal address.
- EINTR
-
A signal was caught during the
link()
function.
- ELOOP
-
Too many symbolic links were encountered in translating path.
- EMLINK
-
The maximum number of links to a file would be exceeded.
- EMULTIHOP
-
Components of
existing
or
new
require hopping to multiple
remote machines and the file system type does not allow it.
- ENAMETOOLONG
-
The length of the existing or new argument
exceeds {PATH_MAX}, or the length of a existing
or new component exceeds {NAME_MAX} while
{_POSIX_NO_TRUNC} is in effect.
- ENOENT
-
existing
or
new
is a null path name.
A component of either path prefix does not exist.
The file named by
existing
does not exist.
- ENOLINK
-
existing
or
new
points to a remote machine and the link
to that machine is no longer active.
- ENOSPC
-
the directory that would contain the link cannot be extended.
- ENOTDIR
-
A component of either path prefix is not a directory.
- EPERM
-
The file named by
existing
is a directory and the effective user of the
calling process is not super-user.
- EROFS
-
The requested link requires writing in a directory on a read-only file system.
- EXDEV
-
The link named by
new
and the file named by
existing
are on different logical devices (file systems).
ATTRIBUTES
See
attributes.5
for descriptions of the following attributes:
+---------------+-------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-------------------+
|MT-Level | Async-Signal-Safe |
+---------------+-------------------+
SEE ALSO
symlink.2
unlink.2
attributes.5
Created by unroff & hp-tools.
© by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 07/October/97
