freebsd-skq/lib/libc/sys/fhreadlink.2
Konstantin Belousov d1fd400a80 Add new file handle system calls.
Namely, getfhat(2), fhlink(2), fhlinkat(2), fhreadlink(2).  The
syscalls are provided for a NFS userspace server (nfs-ganesha).

Submitted by:	Jack Halford <jack@gandi.net>
Sponsored by:	Gandi.net
Tested by:	pho
Feedback from:	brooks, markj
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D18359
2018-12-07 15:17:29 +00:00

93 lines
2.5 KiB
Groff

.\" SPDX-License-Identifier: BSD-2-Clause
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.\" Copyright (c) 2018 Gandi
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.\" $FreeBSD$
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.Dd November 29, 2018
.Dt FHREADLINK 2
.Os
.Sh NAME
.Nm fhreadlink
.Nd read value of a symbolic link
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In sys/mount.h
.Ft int
.Fn fhreadlink "fhandle_t *fhp" "char *buf" "size_t bufsize"
.Fc
.Sh DESCRIPTION
The
.Fn fhreadlink
system call
places the contents of the symbolic link
.Fa fhp
in the buffer
.Fa buf ,
which has size
.Fa bufsiz .
The
.Fn fhreadlink
system call does not append a
.Dv NUL
character to
.Fa buf .
.Pp
.Sh RETURN VALUES
The call returns the count of characters placed in the buffer
if it succeeds, or a \-1 if an error occurs, placing the error
code in the global variable
.Va errno .
.Sh ERRORS
The
.Fn readlink
system call
will fail if:
.Bl -tag -width Er
.It Bq Er ENOENT
The named file does not exist.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating the file handle
.Fa fhp .
.It Bq Er EINVAL
The named file is not a symbolic link.
.It Bq Er EIO
An I/O error occurred while reading from the file system.
.It Bq Er EFAULT
The
.Fa buf
argument
extends outside the process's allocated address space.
.It Bq Er ESTALE
The file handle
.Fa fhp
is no longer valid
.El
.El
.Sh SEE ALSO
.Xr fhstat 2 ,
.Xr fhlink 2 ,