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sigblock(3UCB)	   SunOS/BSD Compatibility Library Functions	sigblock(3UCB)

NAME
       sigblock, sigmask, sigpause, sigsetmask - block signals

SYNOPSIS
       /usr/ucb/cc [ flag ... ]	file ...
       #include	<signal.h>

       int sigblock(mask);
       intmask;

       int sigmask( signum);
       int signum;

       int sigpause(int	mask);
       int mask;

       int sigsetmask( mask);
       int mask;

DESCRIPTION
       sigblock, sigmask, sigpause, sigsetmask - block signals

       sigblock()  adds	 the  signals  specified in mask to the	set of signals
       currently being blocked from delivery.  Signals are blocked if the  ap-
       propriate  bit  in  mask	 is a 1; the macro sigmask is provided to con-
       struct the mask for a given signum.  sigblock()	returns	 the  previous
       mask. The previous mask may be restored using sigsetmask().

       sigpause() assigns mask to the set of masked signals and	then waits for
       a signal	to arrive; on return the set of	masked	signals	 is  restored.
       mask  is	 usually  0 to indicate	that no	signals	are now	to be blocked.
       sigpause() always terminates by being  interrupted,  returning  -1  and
       setting errno to	EINTR.

       sigsetmask()  sets  the	current	 signal	 mask  (those signals that are
       blocked from delivery).	Signals	are blocked if the  corresponding  bit
       in mask is a 1; the macro sigmask is provided to	construct the mask for
       a given signum.

       In normal usage,	a signal is blocked using sigblock(). To begin a crit-
       ical  section,  variables  modified on the occurrence of	the signal are
       examined	to determine that there	is no work to be done, and the process
       pauses awaiting work by using sigpause()	with the mask returned by sig-
       block().

       It is not possible to block SIGKILL, SIGSTOP,  or   SIGCONT,  this  re-
       striction is silently imposed by	the system.

RETURN VALUES
       sigblock()  and sigsetmask() return the previous	set of masked signals.
       sigpause() returns -1 and sets errno to EINTR.

SEE ALSO
       kill(2),	sigaction(2), signal(3UCB), sigvec(3UCB)

NOTES
       Use of these interfaces should be restricted to only applications writ-
       ten  on	BSD platforms.	Use of these interfaces	with any of the	system
       libraries or in multi-thread applications is unsupported.

SunOS 5.9			  19 Feb 1993			sigblock(3UCB)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | NOTES

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