sigsetmask(2) manipulate current signal mask

Other Alias



Lb libc


In signal.h Ft int Fn sigsetmask int mask Ft int Fn sigblock int mask Ft int Fn sigmask int signum


Bf -symbolic This interface is made obsolete by: Ef sigprocmask(2).

The Fn sigsetmask function sets the current signal mask to the specified Fa mask . Signals are blocked from delivery if the corresponding bit in Fa mask is a 1. The Fn sigblock function adds the signals in the specified Fa mask to the current signal mask, rather than overwriting it as Fn sigsetmask does. The macro Fn sigmask is provided to construct the mask for a given Fa signum .

The system quietly disallows SIGKILL or SIGSTOP to be blocked.


The Fn sigblock and Fn sigsetmask functions return the previous set of masked signals.


The Fn sigsetmask and Fn sigblock functions first appeared in BSD 4.2 and have been deprecated.