.\"
.\" Copyright (c) 2006 The DragonFly Project.  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 DragonFly Project 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 COPYRIGHT HOLDERS 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
.\" COPYRIGHT HOLDERS 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.
.\"
.\" $DragonFly: src/lib/libc/sys/caps_sys_getgen.2,v 1.1 2006/02/28 22:40:49 swildner Exp $
.\"
.Dd February 28, 2006
.Dt CAPS_SYS_GETGEN 2
.Os
.Sh NAME
.Nm caps_sys_getgen
.Nd get the generation number for a CAPS IPC link
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/caps.h
.Ft caps_gen_t
.Fn caps_sys_getgen "int portid"
.Sh DESCRIPTION
The
.Fn caps_sys_getgen
function returns the 64 bit generation number for a CAPS link
specified by the
.Fa portid
identifier.
This number is typically used to allow a client to detect when a
service has been restarted.
.Sh RETURN VALUES
On success, the 64 bit generation number is returned.
If an error occurs, -1 is returned and
.Va errno
is set.
.Sh ERRORS
This function will fail if:
.Bl -tag -width ".Bq Er ENOTCONN"
.It Bq Er EINVAL
The
.Fa portid
could not be found.
.It Bq Er ENOTCONN
The process originally creating the port forked and the child
process attempts to access the port.
The child process is expected to create its own port.
.El
.Sh SEE ALSO
.Xr caps_sys_setgen 2
.Sh HISTORY
The
.Fn caps_sys_getgen
function call first appeared in
.Dx 1.0 .
.Sh AUTHORS
.An -nosplit
CAPS IPC was written by
.An Matthew Dillon .
This man page was written by
.An Sascha Wildner .