sigblock - block signals
This interface is made obsolete by: sigprocmask(2).
sigblock() adds the signals specified in mask to the set of
being blocked from delivery. Signals are blocked if
bit in mask is a 1; the macro sigmask() is provided
the mask for a given signum.
It is not possible to block SIGKILL or SIGSTOP; this restriction is
silently imposed by the system.
The previous set of masked signals is returned.
The following example utilizing sigblock():
omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
sigset_t set, oset;
sigprocmask(SIG_BLOCK, &set, &oset);
Another use of sigblock() is to get the current set of
without changing what is actually blocked. Instead of:
set = sigblock(0);
Use the following:
sigprocmask(SIG_BLOCK, NULL, &set);
kill(2), sigaction(2), sigprocmask(2), sigsetmask(3), sigsetops(3)
The sigblock() function call appeared in 4.2BSD and has been
OpenBSD 3.6 March 10, 1991
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