January 12, 1994 LINK 2

### NAME

link - make a hard file link

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```int` link(```const char *name1``, const char *name2`)

### DESCRIPTION

The link(``) function call atomically creates the specified directory entry (hard link) ```name2` with the attributes of the underlying object pointed at by ```name1`. If the link is successful: the link count of the underlying object is incremented; ```name1` and ```name2` share equal access and rights to the underlying object.

If ```name1` is removed, the file ```name2` is not deleted and the link count of the underlying object is decremented.

```name1` must exist for the hard link to succeed and both ```name1` and ```name2` must be in the same file system. ```name1` may not be a directory unless the caller is the super-user and the file system containing it supports linking to directories.

### 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:

[```ENOTDIR`]
  A component of either path prefix is not a directory.

[```ENAMETOOLONG`]
  A component of a pathname exceeded ```{NAME_MAX}` characters, or an entire path name exceeded ```{PATH_MAX}` characters.

[```ENOENT`]
  A component of either path prefix does not exist.

[```EACCES`]
  A component of either path prefix denies search permission, or the requested link requires writing in a directory with a mode that denies write permission.

[```ELOOP`]
  Too many symbolic links were encountered in translating one of the pathnames.

[```ENOENT`]
  The file named by ```name1` does not exist.

[```EOPNOTSUPP`]
  The file system containing the file named by ```name1` does not support links.

[```EMLINK`]
  The link count of the file named by ```name1` would exceed ```{LINK_MAX}`.

[```EEXIST`]
  The link named by ```name2` does exist.

[```EPERM`]
  The file named by ```name1` is a directory and the effective user ID is not super-user, or the file system containing the file does not permit the use of link(``) on a directory.

[```EXDEV`]
  The link named by ```name2` and the file named by ```name1` are on different file systems.

[```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 directory has been exhausted.

[```EIO`]
  An I/O error occurred while reading from or writing to the file system to make the directory entry.

[```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.

### SEE ALSO

symlink(2), unlink(2)

### STANDARDS

The link(``) function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'') .