link - make a new name for a file
int link(const char *oldpath, const char
() creates a new link (also known as a hard link) to an existing
exists it will not
This new name may be used exactly as the old one for any operation; both names
refer to the same file (and so have the same permissions and ownership) and it
is impossible to tell which name was the "original".
On success, zero is returned. On error, -1 is returned, and errno
- Write access to the directory containing newpath is
denied, or search permission is denied for one of the directories in the
path prefix of oldpath or newpath. (See also
- newpath already exists.
- oldpath or newpath points outside your
accessible address space.
- An I/O error occurred.
- Too many symbolic links were encountered in resolving
oldpath or newpath.
- The file referred to by oldpath already has the
maximum number of links to it.
- oldpath or newpath was too long.
- A directory component in oldpath or newpath
does not exist or is a dangling symbolic link.
- Insufficient kernel memory was available.
- The device containing the file has no room for the new
- A component used as a directory in oldpath or
newpath is not, in fact, a directory.
- oldpath is a directory.
- The file system containing oldpath and
newpath does not support the creation of hard links.
- EPERM (since Linux 3.6)
- The caller does not have permission to create a hard link
to this file (see the description of
/proc/sys/fs/protected_hardlink in proc(5)).
- The file is on a read-only file system.
- oldpath and newpath are not on the same
mounted file system. (Linux permits a file system to be mounted at
multiple points, but link() does not work across different mount
points, even if the same file system is mounted on both.)
SVr4, 4.3BSD, POSIX.1-2001 (but see NOTES).
Hard links, as created by link
(), cannot span file systems. Use
if this is required.
POSIX.1-2001 says that link
() should dereference oldpath
if it is
a symbolic link. However, since kernel 2.0, Linux does not do so: if
is a symbolic link, then newpath
is created as a (hard)
link to the same symbolic link file (i.e., newpath
becomes a symbolic
link to the same file that oldpath
refers to). Some other
implementations behave in the same manner as Linux. POSIX.1-2008 changes the
specification of link
(), making it implementation-dependent whether or
is dereferenced if it is a symbolic link. For precise
control over the treatment of symbolic links when creating a link, see
On NFS file systems, the return code may be wrong in case the NFS server
performs the link creation and dies before it can say so. Use stat(2)
to find out if the link got created.
This page is part of release 3.44 of the Linux man-pages
description of the project, and information about reporting bugs, can be found