link(2) - NetBSD Manual Pages

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LINK(2)                   NetBSD Programmer's Manual                   LINK(2)


NAME

     link - make a hard file link


SYNOPSIS

     #include <unistd.h>

     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 link-
     ing 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.

     [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.

     [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 al-
                   located address space.


SEE ALSO

     symlink(2), unlink(2)


STANDARDS

     The link() function conforms to IEEE Std1003.1-1990 (``POSIX'').

NetBSD 1.4                     January 12, 1994                              2