traditional single-threaded application, sigprocmask (2) can be used to manipulate the signal mask ... state of the signal mask (using sigprocmask (2)), if it is desired to unblockbelow signal (2) sigpause (3) sigpending (2) sigprocmask (2) sigqueue (2) sigset (3) sigsuspendsigaction (2), signalfd (2), sigpending (2), sigprocmask (2), sigsuspend (2), sigwaitinfo (2), signal (7) NOTES3.Reset the signal mask using sigprocmask() . 4.Sanitize the environment block, removing or resetting environment variablessignal set argument of these calls. • The sigprocmask (2) and pthread_sigmask (3) interfaces silently