.\" Copyright (c) 1983 Regents of the University of California. .\" All rights reserved. The Berkeley software License Agreement .\" specifies the terms and conditions for redistribution. .\" .\" @(#)sigblock.2 6.1 (Berkeley) 05/15/85 .\" .TH SIGBLOCK 2 "" .UC 5 .SH NAME sigblock \- block signals .SH SYNOPSIS .nf .B sigblock(mask); .B int mask; .SH DESCRIPTION .I Sigblock causes the signals specified in .I mask to be added to the set of signals currently being blocked from delivery. Signal .I i is blocked if the .IR i -th bit in .I mask is a 1. .PP It is not possible to block SIGKILL, SIGSTOP, or SIGCONT; this restriction is silently imposed by the system. .SH "RETURN VALUE The previous set of masked signals is returned. .SH "SEE ALSO" kill(2), sigvec(2), sigsetmask(2),