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lib/libc/sys/fhlink.2
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.\" SPDX-License-Identifier: BSD-2-Clause | |||||
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.\" Copyright (c) 2018 Gandi | |||||
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.\" $FreeBSD$ | |||||
.\" | |||||
.Dd November 29, 2018 | |||||
.Dt FHLINK 2 | |||||
.Os | |||||
.Sh NAME | |||||
.Nm fhlink , | |||||
.Nm fhlinkat | |||||
.Nd make a hard file link | |||||
.Sh LIBRARY | |||||
.Lb libc | |||||
.Sh SYNOPSIS | |||||
.In unistd.h | |||||
.Ft int | |||||
.Fn fhlink "fhandle_t *fhp" "const char *to" | |||||
.Ft int | |||||
.Fn fhlinkat "fhandle_t *fhp" "int tofd" "const char *to" | |||||
.Fc | |||||
Not Done Inline Actionss/link/fhlink/ ? brooks: s/link/fhlink/ ? | |||||
.Sh DESCRIPTION | |||||
The | |||||
.Fn fhlink | |||||
system call | |||||
atomically creates the specified directory entry (hard link) | |||||
.Fa to | |||||
with the attributes of the underlying object pointed at by | |||||
.Fa fhp . | |||||
If the link is successful: the link count of the underlying object | |||||
is incremented; | |||||
.Fa fhp | |||||
and | |||||
.Fa to | |||||
share equal access and rights | |||||
to the | |||||
underlying object. | |||||
.Pp | |||||
If | |||||
.Fa fhp | |||||
is removed, the file | |||||
.Fa to | |||||
is not deleted and the link count of the | |||||
underlying object is | |||||
decremented. | |||||
.Pp | |||||
The object pointed at by the | |||||
.Fa fhp | |||||
argument | |||||
must exist for the hard link to | |||||
succeed and | |||||
both | |||||
.Fa fhp | |||||
and | |||||
.Fa to | |||||
must be in the same file system. | |||||
The | |||||
.Fa fhp | |||||
argument | |||||
may not be a directory. | |||||
.Pp | |||||
The | |||||
.Fn fhlinkat | |||||
system call is equivalent to | |||||
.Fa fhlink | |||||
except in the case where | |||||
.Fa to | |||||
is a relative paths. | |||||
In this case a relative path | |||||
.Fa to | |||||
is interpreted relative to | |||||
the directory associated with the file descriptor | |||||
.Fa tofd | |||||
instead of the current working directory. | |||||
.Pp | |||||
Values for | |||||
.Fa flag | |||||
are constructed by a bitwise-inclusive OR of flags from the following | |||||
list, defined in | |||||
.In fcntl.h : | |||||
.Bl -tag -width indent | |||||
.It Dv AT_SYMLINK_FOLLOW | |||||
If | |||||
.Fa fhp | |||||
names a symbolic link, a new link for the target of the symbolic link is | |||||
created. | |||||
.It Dv AT_BENEATH | |||||
Only allow to link to a file which is beneath of the topping directory. | |||||
See the description of the | |||||
.Dv O_BENEATH | |||||
flag in the | |||||
.Xr open 2 | |||||
manual page. | |||||
.El | |||||
.Pp | |||||
If | |||||
.Fn fhlinkat | |||||
is passed the special value | |||||
.Dv AT_FDCWD | |||||
in the | |||||
.Fa tofd | |||||
parameter, the current working directory is used for the | |||||
.Fa to | |||||
argument. | |||||
If | |||||
.Fa tofd | |||||
has value | |||||
.Dv AT_FDCWD , | |||||
the behavior is identical to a call to | |||||
.Fn link . | |||||
Unless | |||||
.Fa flag | |||||
contains the | |||||
.Dv AT_SYMLINK_FOLLOW | |||||
flag, if | |||||
.Fa fhp | |||||
names a symbolic link, a new link is created for the symbolic link | |||||
.Fa fhp | |||||
and not its target. | |||||
.Sh RETURN VALUES | |||||
.Rv -std link | |||||
.Sh ERRORS | |||||
The | |||||
.Fn fhlink | |||||
system call | |||||
will fail and no link will be created if: | |||||
.Bl -tag -width Er | |||||
.It Bq Er ENOTDIR | |||||
A component of | |||||
.Fa to | |||||
prefix is not a directory. | |||||
.It Bq Er ENAMETOOLONG | |||||
A component of | |||||
.Fa to | |||||
exceeded 255 characters, | |||||
or entire length of | |||||
.Fa to | |||||
name exceeded 1023 characters. | |||||
.It Bq Er ENOENT | |||||
A component of | |||||
.Fa to | |||||
prefix does not exist. | |||||
.It Bq Er EOPNOTSUPP | |||||
The file system containing the file pointed at by | |||||
.Fa fhp | |||||
does not support links. | |||||
.It Bq Er EMLINK | |||||
The link count of the file pointed at by | |||||
.Fa fhp | |||||
would exceed 32767. | |||||
.It Bq Er EACCES | |||||
A component of | |||||
.Fa to | |||||
prefix denies search permission. | |||||
.It Bq Er EACCES | |||||
The requested link requires writing in a directory with a mode | |||||
that denies write permission. | |||||
.It Bq Er ELOOP | |||||
Too many symbolic links were encountered in translating one of the pathnames. | |||||
.It Bq Er ENOENT | |||||
The file pointed at by | |||||
.Fa fhp | |||||
does not exist. | |||||
.It Bq Er EEXIST | |||||
The link named by | |||||
.Fa to | |||||
does exist. | |||||
.It Bq Er EPERM | |||||
The file pointed at by | |||||
.Fa fhp | |||||
is a directory. | |||||
.It Bq Er EPERM | |||||
The file pointed at by | |||||
.Fa fhp | |||||
has its immutable or append-only flag set, see the | |||||
.Xr chflags 2 | |||||
manual page for more information. | |||||
.It Bq Er EPERM | |||||
The parent directory of the file named by | |||||
.Fa to | |||||
has its immutable flag set. | |||||
.It Bq Er EXDEV | |||||
The link named by | |||||
.Fa to | |||||
and the file pointed at by | |||||
.Fa fhp | |||||
are on different file systems. | |||||
.It Bq Er 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. | |||||
.It Bq Er 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. | |||||
.It Bq Er EIO | |||||
An I/O error occurred while reading from or writing to | |||||
the file system to make the directory entry. | |||||
.It Bq Er EROFS | |||||
The requested link requires writing in a directory on a read-only file | |||||
system. | |||||
.It Bq Er EFAULT | |||||
One of the pathnames specified | |||||
is outside the process's allocated address space. | |||||
.It Bq Er ESTALE | |||||
The file handle | |||||
.Fa fhp | |||||
is no longer valid | |||||
.El | |||||
.Pp | |||||
In addition to the errors returned by the | |||||
.Fn fhlink , | |||||
the | |||||
.Fn fhlinkat | |||||
system call may fail if: | |||||
.Bl -tag -width Er | |||||
.It Bq Er EBADF | |||||
The | |||||
.Fa fhp | |||||
or | |||||
.Fa to | |||||
argument does not specify an absolute path and the | |||||
.Fa tofd | |||||
argument, is not | |||||
.Dv AT_FDCWD | |||||
nor a valid file descriptor open for searching. | |||||
.It Bq Er EINVAL | |||||
The value of the | |||||
.Fa flag | |||||
argument is not valid. | |||||
.It Bq Er ENOTDIR | |||||
The | |||||
.Fa fhp | |||||
or | |||||
.Fa to | |||||
argument is not an absolute path and | |||||
.Fa tofd | |||||
is not | |||||
.Dv AT_FDCWD | |||||
nor a file descriptor associated with a directory. | |||||
.El | |||||
.Sh SEE ALSO | |||||
.Xr fhstat 2 , | |||||
.Xr fhreadlink 2 , | |||||
.Xr fhopen 2 , |
I am sure that UCB has nothing to do with the new file. Please update copyright with the proper reference (to your personally or to Gandi). Same for fhreadlink.
BTW, preferred license for the new files is two clause BSD, see share/examples/etc/bsd-style-copyright. Please consider using it.