System Calls link(2)
NAME
link - link to a file
SYNOPSIS
#include <unistd.h>
int link(const char *existing, const char *new);
DESCRIPTION
The link() function creates a new link (directory entry) for
the existing file and increments its link count by one. The
existing argument points to a path name naming an existing
file. The new argument points to a pathname naming the new
directory entry to be created.
To create hard links, both files must be on the same file
system. Both the old and the new link share equal access and
rights to the underlying object. The super-user may make
multiple links to a directory. Unless the caller is the
super-user, the file named by existing must not be a direc-
tory.
Upon successful completion, link() marks for update the
st_ctime field of the file. Also, the st_ctime and st_mtime
fields of the directory that contains the new entry are
marked for update.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is
returned, no link is created, and errno is set to indicate
the error.
ERRORS
The link() function will fail if:
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 per-
mission.
EDQUOT The directory where the entry for the new link is
being placed cannot be extended because the user's
quota of disk blocks on that file system has been
exhausted.
EEXIST The link named by new exists.
EFAULT The existing or new argument points to an illegal
address.
EINTR A signal was caught during the execution of the
link() function.
System Calls link(2)
ELOOP Too many symbolic links were encountered in
translating path.
EMLINK The maximum number of links to a file would be
exceeded.
ENAMETOOLONG
The length of the existing or new argument exceeds
PATH_MAX, or the length of a existing or new com-
ponent exceeds NAME_MAX while _POSIX_NO_TRUNC is
in effect.
ENOENT The existing or new argument is a null pathname; a
component of either path prefix does not exist; or
the file named by existing does not exist.
ENOLINK The existing or new argument points to a remote
machine and the link to that machine is no longer
active.
ENOSPC The directory that would contain the link cannot
be extended.
ENOTDIR A component of either path prefix is not a direc-
tory.
EPERM The file named by existing is a directory and the
effective user of the calling process is not
super-user.
EROFS The requested link requires writing in a directory
on a read-only file system.
EXDEV The link named by new and the file named by exist-
ing are on different logical devices (file sys-
tems).
SEE ALSO
symlink(2), unlink(2)
Everything2 Last change: 5 July 2000 2