link(2)

NAME
     link - make a hard link to a file

SYNOPSIS
     #include <unistd.h>

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

DESCRIPTION
     A hard link to name1 is created; the link has the name name2.  Name1 must
     exist.

     With hard links, both name1 and name2 must be in the  same  file  system.
     Name1 must not be a directory.  Both the old and the new link share equal
     access and rights to the underlying object.

RETURN VALUE
     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  one  or  more  of  the
     following are true:

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

     [ENAMETOOLONG] A path name exceeds PATH_MAX characters.

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

     [EACCES]       A  component  of  either   path   prefix   denies   search
                    permission.

     [EACCES]       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.  (Minix-vmd)

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

     [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.

     [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.

     [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).