SIGBLOCK(3B)							  SIGBLOCK(3B)

NAME    [Toc]    [Back]

     sigblock -	block signals from delivery to process (4.3BSD)

SYNOPSIS    [Toc]    [Back]

     #include <signal.h>

     int sigblock(int mask);

     mask = sigmask(int	signum);

     To	use any	of the BSD signal routines (kill(3B), killpg(3B),
     sigblock(3B), signal(3B), sigpause(3B), sigsetmask(3B), sigstack(2B),
     sigvec(3B)) you must either

     1)	#define	_BSD_SIGNALS or	_BSD_COMPAT before including <signal.h>, or

     2)	specify	one of them in the compile command or makefile:

	  cc -D_BSD_SIGNALS -o prog prog.c

DESCRIPTION    [Toc]    [Back]

     sigblock causes the signals specified in mask to be added to the set of
     signals currently being blocked from delivery.  Signals are blocked if
     the corresponding bit in mask is a	1 (numbering the bits from 1 to	32);
     the macro sigmask is provided to construct	the mask for a given signum.

     It	is not possible	to block SIGKILL, SIGSTOP, or SIGCONT; this
     restriction is imposed silently by	the system.

RETURN VALUE    [Toc]    [Back]

     The previous set of masked	signals	is returned.

SEE ALSO    [Toc]    [Back]

     kill(3B), sigvec(3B), sigsetmask(3B), signal(5).

WARNING	(IRIX)
     The 4.3BSD	and System V signal facilities have different semantics.
     Using both	facilities in the same program is strongly discouraged and
     will result in unpredictable behavior.


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