SIGBLOCK(2) BSD Programmer's Manual SIGBLOCK(2)
sigblock - block signals
This interface is made obsolete by: sigprocmask(2).
Sigblock() adds the signals specified in mask to the set of signals cur-
rently being blocked from delivery. Signals are blocked if the corre-
sponding bit in mask is a 1; the macro sigmask() is provided to construct
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.
kill(2), sigprocmask(2), sigaction(2), sigsetmask(2), sigsetops(3)
The sigblock function call appeared in 4.2BSD and has been deprecated.
4.2 Berkeley Distribution June 2, 1993 1