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FHLINK(2) FreeBSD System Calls Manual FHLINK(2)
NAME
fhlink, fhlinkat - make a hard file link
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
fhlink(fhandle_t *fhp, const char *to);
int
fhlinkat(fhandle_t *fhp, int tofd, const char *to);
DESCRIPTION
The fhlink() system call atomically creates the specified directory entry
(hard link) to with the attributes of the underlying object pointed at by
fhp. If the link is successful: the link count of the underlying object
is incremented; fhp and to share equal access and rights to the
underlying object.
If fhp is removed, the file to is not deleted and the link count of the
underlying object is decremented.
The object pointed at by the fhp argument must exist for the hard link to
succeed and both fhp and to must be in the same file system. The fhp
argument may not be a directory.
The fhlinkat() system call is equivalent to fhlink except in the case
where to is a relative paths. In this case a relative path to is
interpreted relative to the directory associated with the file descriptor
tofd instead of the current working directory.
If fhlinkat() is passed the special value AT_FDCWD in the tofd parameter,
the current working directory is used for the to argument. If tofd has
value AT_FDCWD, the behavior is identical to a call to link(). Unless
flag contains the AT_SYMLINK_FOLLOW flag, if fhp names a symbolic link, a
new link is created for the symbolic link fhp and not its target.
RETURN VALUES
The link() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
The fhlink() system call will fail and no link will be created if:
[ENOTDIR] A component of to prefix is not a directory.
[ENAMETOOLONG] A component of to exceeded 255 characters, or entire
length of to name exceeded 1023 characters.
[ENOENT] A component of to prefix does not exist.
[EOPNOTSUPP] The file system containing the file pointed at by fhp
does not support links.
with a mode that denies write permission.
[ELOOP] Too many symbolic links were encountered in
translating one of the pathnames.
[ENOENT] The file pointed at by fhp does not exist.
[EEXIST] The link named by to does exist.
[EPERM] The file pointed at by fhp is a directory.
[EPERM] The file pointed at by fhp has its immutable or
append-only flag set, see the chflags(2) manual page
for more information.
[EPERM] The parent directory of the file named by to has its
immutable flag set.
[EXDEV] The link named by to and the file pointed at by fhp
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.
[EINTEGRITY] Corrupted data was detected while reading from the
file system.
[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.
[ESTALE] The file handle fhp is no longer valid
In addition to the errors returned by the fhlink(), the fhlinkat() system
call may fail if:
[EBADF] The fhp or to argument does not specify an absolute
path and the tofd argument, is not AT_FDCWD nor a
valid file descriptor open for searching.
[EINVAL] The value of the flag argument is not valid.
[ENOTDIR] The fhp or to argument is not an absolute path and
tofd is not AT_FDCWD nor a file descriptor associated
with a directory.
SEE ALSO