SIGBLOCK
NAME
sigblock, siggetmask, sigsetmask, sigmask - manipulate the signal mask
SYNOPSIS
#include <signal.h>
I int sigblock(int mask );
int siggetmask(void);
I int sigsetmask(int mask );
I int sigmask(int signum );
DESCRIPTION
This interface is made obsolete by
sigprocmask(2).
The
R sigblock ()
system call adds the signals specified in
mask
to the set of signals currently being blocked from delivery.
The
R sigsetmask ()
system call replaces the set of blocked signals totally with a new set
specified in
R mask .
Signals are blocked if the corresponding bit in
mask
is a 1.
The current set of blocked signals can be obtained using
R siggetmask ().
The
R sigmask ()
macro is provided to construct the mask for a given
R signum .
RETURN VALUE
R siggetmask ()
returns the current set of masked signals.
R sigsetmask ()
and
R sigblock ()
return the previous set of masked signals.
NOTES
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.
CONFORMING TO
4.4BSD. These function calls appeared in 4.3BSD and are deprecated.
Use the POSIX signal facilities for new programs.
SEE ALSO
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