sigblock(2) sigblock(2)
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NAME [Toc] [Back]
sigblock - block signals
SYNOPSIS [Toc] [Back]
#include <signal.h>
long sigblock(long mask);
DESCRIPTION [Toc] [Back]
sigblock() causes the signals specified in mask to be added to the set
of signals currently being blocked from delivery. Signal i is blocked
if the i-th bit in mask is 1, as specified with the macro sigmask(i).
It is not possible to block signals that cannot be ignored, as
documented in signal(5); this restriction is silently imposed by the
system.
Use sigsetmask() to set the mask absolutely (see sigsetmask(2)).
RETURN VALUE [Toc] [Back]
sigblock() returns the previous set of masked signals.
EXAMPLES [Toc] [Back]
The following call to sigblock() adds the SIGUSR1 and SIGUSR2 signals
to the mask of signals currently blocked for the process:
long oldmask;
oldmask = sigblock (sigmask (SIGUSR1) | sigmask (SIGUSR2));
WARNINGS [Toc] [Back]
Do not use sigblock() in conjunction with the facilities described
under sigset(3C).
Obsolescent Interfaces [Toc] [Back]
sigblock() is to be obsoleted at a future date.
APPLICATION USAGE [Toc] [Back]
Threads Considerations
Since each thread maintains its own blocked signal mask, sigblock()
modifies only the calling thread's blocked signal mask.
For more information regarding signals and threads, refer to
signal(5).
LP64 Programs [Toc] [Back]
sigblock() accepts and returns long (64 bit) values. However, as for
ILP32 programs, sigblock() supports signals numbered 1 through 32.
The upper 32 bits of the mask argument are ignored. Also, the upper
32 bits of the returned mask have no meaning.
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003
sigblock(2) sigblock(2)
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AUTHOR [Toc] [Back]
sigblock() was developed by the University of California, Berkeley.
SEE ALSO [Toc] [Back]
kill(2), sigprocmask(2), sigsetmask(2), sigvector(2), signal(5).
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: August 2003 [ Back ] |
