1.\" Copyright (C) 2000 Jason Evans <[email protected]>. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 20.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 26.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd April 27, 2000 31.Dt SIGWAIT 2 32.Os 33.Sh NAME 34.Nm sigwait 35.Nd select a set of signals 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In signal.h 40.Ft int 41.Fn sigwait "const sigset_t * restrict set" "int * restrict sig" 42.Sh DESCRIPTION 43The 44.Fn sigwait 45system call selects a set of signals, specified by 46.Fa set . 47If none of the selected signals are pending, 48.Fn sigwait 49waits until one or more of the selected signals has been generated. 50Then 51.Fn sigwait 52atomically clears one of the selected signals from the set of pending signals 53for the process and sets the location pointed to by 54.Fa sig 55to the signal number that was cleared. 56.Pp 57The signals specified by 58.Fa set 59should be blocked at the time of the call to 60.Fn sigwait . 61.Sh RETURN VALUES 62If successful, 63.Fn sigwait 64returns 0 and sets the location pointed to by 65.Fa sig 66to the cleared signal number. 67Otherwise, an error number is returned. 68.Sh ERRORS 69The 70.Fn sigwait 71system call will fail if: 72.Bl -tag -width Er 73.It Bq Er EINVAL 74The 75.Fa set 76argument 77specifies one or more invalid signal numbers. 78.El 79.Sh SEE ALSO 80.Xr sigaction 2 , 81.Xr sigpending 2 , 82.Xr sigsuspend 2 , 83.Xr pause 3 , 84.Xr pthread_sigmask 3 85.Sh STANDARDS 86The 87.Fn sigwait 88function conforms to 89.St -p1003.1-96 . 90