SIGBLOCK(2) Linux Programmer's Manual SIGBLOCK(2)
sigblock, siggetmask, sigsetmask, sigmask - manipulate the signal mask
int sigblock(int mask);
int sigsetmask(int mask);
int sigmask(int signum);
This interface is made obsolete by sigprocmask(2).
The sigblock system call adds the signals specified in mask to the set
of signals currently being blocked from delivery.
The sigsetmask system call replaces the set of blocked signals totally
with a new set specified in mask. Signals are blocked if the corre-
sponding bit in mask is a 1.
The current set of blocked signals can be obtained using siggetmask.
The sigmask macro is provided to construct the mask for a given signum.
siggetmask returns the current set of masked signals.
sigsetmask and sigblock return the previous set of masked signals.
Prototypes for these functions are only available if _BSD_SOURCE is
defined before the inclusion of any system header file.
It is not possible to block SIGKILL or SIGSTOP - this restriction is
silently imposed by the system.
4.4BSD. These function calls appeared in BSD 4.3 and are deprecated.
Use the POSIX signal facilities for new programs.
kill(2), sigprocmask(2), signal(7)
Linux 1.3 1995-08-31 SIGBLOCK(2)