link(2)link(2)NAMElink - Create a hard link to an existing file on the local file system
const char *path1,
const char *path2 );
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
link(): XSH4.0, XSH4.2, XSH5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
Points to the pathname of an existing file. Points to the pathname for
the directory entry to be created. If the path2 parameter names a sym‐
bolic link, an error is returned.
The link() function creates an additional hard link (directory entry)
for an existing file. The old and the new link share equal access
rights to the underlying object. The link() function atomically cre‐
ates a new link for the existing file and increments the link count of
the file by one.
Both the path1 and path2 parameters must reside on the same file sys‐
tem. A hard link to a directory cannot be created.
Upon successful completion, the link() function marks the st_ctime
field of the file for update, and marks the st_ctime and st_mtime
fields of the directory containing the new entry for update.
A process must have write permission in the target directory with
respect to all access control policies configured on the system.
See symlink(2) for information about making symbolic links, including
Context Dependent Symbolic Links (CDSLs).
Upon successful completion, the link() function returns a value of 0
(zero). If the link() function fails, a value of -1 is returned, no
link is created, and errno is set to indicate the error.
If the link() function fails, errno may be set to one of the following
values: The requested link requires writing in a directory with a mode
that denies write permission, or a component of either the path1 or
path2 parameter denies search permission.
The requested link requires writing in a directory to which the
process does not have write access with respect to one or more
of the system's configured access policies. [Tru64 UNIX] The
directory in which the entry for the new link is being placed
cannot be extended because the user's quota of disk blocks on
the file system containing the directory has been exhausted.
The link named by the path2 parameter already exists. [Tru64
UNIX] The path1 or path2 parameter is an invalid address.
[Tru64 UNIX] An I/O error occurred when updating the directory.
Too many links were encountered in translating path1 or path2.
The number of links to the file named by path1 would exceed
LINK_MAX. The length of the path1 or path2 string exceeds
PATH_MAX or a pathname component is longer than NAME_MAX. The
file named by the path1 parameter does not exist or the path1 or
path2 parameter is an empty string. The directory in which the
entry for the new link is being placed cannot be extended
because there is no space left on the file system containing the
directory. A component of either path prefix is not a direc‐
tory. The file named by the path1 parameter is a directory.
The requested link requires writing in a directory on a read-
only file system. The link named by the path2 parameter and the
file named by the path1 parameter are on different file systems,
or path1 refers to a STREAM.
[Tru64 UNIX] For NFS file access, if the link() function fails, errno
may also be set to one of the following values: Indicates that the sys‐
tem file table is full or there are too many files currently open in
the system. Indicates a stale NFS file handle. An opened file was
deleted by the server or another client; a client cannot open a file
because the server has unmounted or unexported the remote directory; or
the directory that contains an opened file was unmounted or unexported
by the server.
Commands: link(1), unlink(1)
Functions: symlink(2), unlink(2)