NAME

     sigblock, siggetmask, sigsetmask, sigmask -  manipulate  the
     signal mask


SYNOPSIS

     #include <signal.h>

     int sigblock(int mask));

     int siggetmask(void);

     int sigsetmask(int mask));

     int sigmask(int signum));


DESCRIPTION

     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  sig-
     nals  totally with a new set specified in mask.  Signals are
     blocked if the corresponding 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.



RETURN VALUES

     siggetmask returns the current set of masked signals.

     sigsetmask and sigblock return the previous  set  of  masked
     signals.


NOTES

     Prototypes  for  these  functions  are  only  available   if
     __USE_BSD is defined before <signal.h> is included.

     It is not possible to block SIGKILL or SIGSTOP -  this  res-
     triction is silently imposed by the system.



CONFORMING TO

     4.4BSD. These function calls appeared in  BSD  4.3  and  are
     deprecated.   Use  the  POSIX signal facilities for new pro-
     grams.



SEE ALSO

     kill(2), sigprocmask(2), signal(7)