The sigblock() function causes the signals specified by the mask parameter to be added to the set of signals currently being blocked from delivery. The signals are blocked from delivery by logically ORing the mask parameter into the signal mask of the process. Signal i is blocked if the i-th bit in the mask parameter is a value of 1. Only signals with values 1-31 can be masked with the sigblock() function.
It is not possible to block SIGKILL. The system provides no indication of this restriction.
The sigblock() function is provided for compatibility to other UNIX systems. Its function is a subset of the sigprocmask() function.
Functions: kill(2), sigaction(2), sigpause(3), sigprocmask(2), sigsuspend(2), sigvec(2) delim off