freebsd-dev/lib/libc/gen/gethostname.3
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

132 lines
3.6 KiB
Groff

.\" Copyright (c) 1983, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)gethostname.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd August 18, 2003
.Dt GETHOSTNAME 3
.Os
.Sh NAME
.Nm gethostname ,
.Nm sethostname
.Nd get/set name of current host
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn gethostname "char *name" "size_t namelen"
.Ft int
.Fn sethostname "const char *name" "int namelen"
.Sh DESCRIPTION
The
.Fn gethostname
function
returns the standard host name for the current processor, as
previously set by
.Fn sethostname .
The
.Fa namelen
argument
specifies the size of the
.Fa name
array.
The returned name is null-terminated unless insufficient space is provided.
.Pp
The
.Fn sethostname
function
sets the name of the host machine to be
.Fa name ,
which has length
.Fa namelen .
This call is restricted to the super-user and
is normally used only when the system is bootstrapped.
.Pp
Host names are limited to
.Brq Dv HOST_NAME_MAX
characters, not including the trailing null, currently 255.
.Sh RETURN VALUES
.Rv -std
.Sh ERRORS
The following errors may be returned by these calls:
.Bl -tag -width Er
.It Bq Er EFAULT
The
.Fa name
or
.Fa namelen
argument gave an
invalid address.
.It Bq Er ENAMETOOLONG
The current host name is longer than
.Fa namelen .
(For
.Fn gethostname
only.)
.It Bq Er EPERM
The caller tried to set the host name and was not the super-user.
.El
.Sh SEE ALSO
.Xr sysconf 3 ,
.Xr sysctl 3
.Sh STANDARDS
The
.Fn gethostname
function conforms to
.St -p1003.1-2001 .
Callers should be aware that
.Brq Dv HOST_NAME_MAX
may be variable or infinite, but is guaranteed to be no less than
.Brq Dv _POSIX_HOST_NAME_MAX .
On older systems, this limit was defined in the non-standard header
.In sys/param.h
as
.Dv MAXHOSTNAMELEN ,
and counted the terminating null.
The
.Fn sethostname
function and the error returns for
.Fn gethostname
are not standardized.
.Sh HISTORY
The
.Fn gethostname
function appeared in
.Bx 4.2 .
The
.Fa namelen
argument to
.Fn gethostname
was changed to
.Vt size_t
in
.Fx 5.2
for alignment with
.St -p1003.1-2001 .