SIGBLOCK(2) System Calls SIGBLOCK(2)
sigblock, sigmask - temporarily block signals
long sigblock(long mask);
sigblock is used to temporarily block the reception of signals. The
input parameter mask is a bit vector that specifies which signals are
to be blocked; a 1 in bit n will block signal n+1. The mask is bit-
wise-or'd with the current signal mask to create the new signal mask.
sigmask is a macro that can be used to calculate signal masks for
sigsetmask. It takes a signal number signum, as listed in signal(2),
as an argument and returns a mask corresponding to that signal.
If a signal is sent to a process but is blocked, the event is recorded
for later release by sigsetmask(2). blocked signals are not stacked;
further occurrences of a blocked signal will overwrite any previous
pending signal of the same signum.
It is not possible to block SIGKILL, SIGCONT, or SIGSTOP. This
restriction is silently enforced by the kernel.
The previous value of the signal mask is returned.
kill(2), sigsetmask(2), signal(2)
GNO 19 January 1997 SIGBLOCK(2)
Man(1) output converted with