link(2)link(2)Namelink - link to a file
char *name1, *name2;
A hard link to name1 is created; the link has the name name2. The
name1 must exist.
With hard links, both name1 and name2 must be in the same file system.
Unless the caller is the superuser, name1 must not be a directory.
Both the old and the new share equal access and rights to the underly‐
Upon successful completion, a value of 0 is returned. Otherwise, a
value of -1 is returned, and errno is set to indicate the error.
The system call fails and no link is created under the following condi‐
[ENOTDIR] A component of either path prefix is not a directory.
[ENAMETOOLONG] A component of either pathname exceeded 255 characters,
or the entire length of either pathname exceeded 1023
[ENOENT] A component of either path prefix does not exist.
[ENOENT] The file named by name1 does not exist.
[ENOENT] When name1 or name2 point to an empty string and the
environment defined is POSIX or SYSTEM_FIVE.
[EACCES] A component of either path prefix denies search permis‐
[EACCES] The requested link requires writing in a directory with
a mode that denies write permission.
[EEXIST] The link named by name2 does exist.
[EPERM] The file named by name1 is a directory, and the effec‐
tive user ID is not that of superuser or the environment
defined is POSIX.
[EXDEV] The link named by name2 and the file named by name1 are
on different file systems.
[EROFS] The requested link requires writing in a directory on a
read-only file system.
[EFAULT] One of the pathnames specified is outside the process's
allocated address space.
[ELOOP] Too many symbolic links were encountered in translating
one of the pathnames.
[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.
[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 direc‐
tory has been exhausted.
[EIO] An I/O error occurred while reading from or writing to
the file system to make the directory entry.
[ESTALE] The file handle given in the argument is invalid. The
file referred to by that file handle no longer exists or
has been revoked.
[ETIMEDOUT] A connect request or remote file operation failed
because the connected party did not properly respond
after a period of time that is dependent on the communi‐
[EMLINK] The number of links to the file named by path1 would
In the POSIX environment, linking to directories is not allowed.
See Alsosymlink(2), unlink(2)link(2)