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.
from: @(#)sigblock.2 8.1 (Berkeley) 6/2/93
$NetBSD: sigblock.3,v 1.16 2003/04/16 13:34:35 wiz Exp $
.Dd August 10, 2002 .Dt SIGBLOCK 3 .Os .Sh NAME .Nm sigblock .Nd block signals .Sh LIBRARY .Lb libc .Sh SYNOPSIS n signal.h .Ft int .Fn sigblock "int mask" .Ft int .Fn sigmask signum .Sh DESCRIPTION f -symbolic This interface is made obsolete by: .Xr sigprocmask 2 . .Ef
p .Fn sigblock adds the signals specified in .Fa mask to the set of signals currently being blocked from delivery. Signals are blocked if the corresponding bit in .Fa mask is a 1; the macro .Fn sigmask is provided to construct the mask for a given .Fa signum .
p It is not possible to block .Dv SIGKILL or .Dv SIGSTOP ; this restriction is silently imposed by the system. .Sh RETURN VALUES The previous set of masked signals is returned. .Sh EXAMPLES The following example using .Fn sigblock : d -literal -offset indent int omask; omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP)); .Ed
p Becomes: d -literal -offset indent sigset_t set, oset; sigemptyset(&set); sigaddset(&set, SIGINT); sigaddset(&set, SIGHUP); sigprocmask(SIG_BLOCK, &set, &oset); .Ed
p Another use of .Fn sigblock is to get the current set of masked signals without changing what is actually blocked. Instead of: d -literal -offset indent int set; set = sigblock(0); .Ed
p Use the following: d -literal -offset indent sigset_t set; sigprocmask(SIG_BLOCK, NULL, &set); .Ed .Sh SEE ALSO .Xr kill 2 , .Xr sigaction 2 , .Xr sigprocmask 2 , .Xr sigsetmask 3 , .Xr sigsetops 3 .Sh HISTORY The .Fn sigblock function call appeared in x 4.2 and has been deprecated.