link - Creates a hard link to an existing file on the local file system
int link (
const char *path1,
const char *path2 );
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path1 Points to the pathname of an existing file.
path2 Points to the pathname for the directory entry to be created. If
the path2 parameter names a symbolic 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 creates 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 system. 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 Con-
text 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
[EACCES] 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.
[EACCES] 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.
[EDQUOT] 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.
[EEXIST] The link named by the path2 parameter already exists.
[EFAULT] The path1 or path2 parameter is an invalid address.
[EIO] [Tru64 UNIX] An I/O error occurred when updating the directory.
[ELOOP] Too many links were encountered in translating path1 or path2.
[EMLINK] The number of links to the file named by path1 would exceed
The length of the path1 or path2 string exceeds PATH_MAX or a
pathname component is longer than NAME_MAX.
[ENOENT] The file named by the path1 parameter does not exist or the path1
or path2 parameter is an empty string.
[ENOSPC] 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.
[ENOTDIR] A component of either path prefix is not a directory.
[EPERM] The file named by the path1 parameter is a directory.
[EROFS] The requested link requires writing in a directory on a read-only
[EXDEV] The link named by the path2 parameter and the file named by the
path1 parameter are on different file systems.
[Tru64 UNIX] For NFS file access, if the link() function fails, errno may
also be set to one of the following values:
[ENFILE] Indicates that the system file table is full or there are too
many files currently open in the system.
[ESTALE] 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 unex-
ported by the server.
Commands: link(1), unlink(1)
Functions: unlink(2), symlink(2)