NAME    [Toc]    [Back]

     sigsetmask - set current signal mask

SYNOPSIS    [Toc]    [Back]

     #include <signal.h>

     int
     sigsetmask(int mask);

     sigmask(int signum);

DESCRIPTION    [Toc]    [Back]

     This interface is made obsoleted by:  sigprocmask(2).

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

     The system  quietly  disallows  SIGKILL  or  SIGSTOP  to  be
blocked.

RETURN VALUES    [Toc]    [Back]

     The previous set of masked signals is returned.

EXAMPLES    [Toc]    [Back]

     The following example utilizing sigsetmask():

           int omask;

           omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));

           ...

           sigsetmask(omask    &    ~(sigmask(SIGINT)    |   sigmask(SIGHUP)));

     Could be converted literally to:

           sigset_t set, oset;

           sigemptyset(&set);
           sigaddset(&set, SIGINT);
           sigaddset(&set, SIGHUP);
           sigprocmask(SIG_BLOCK, &set, &oset);

           ...

           sigdelset(&oset, SIGINT);
           sigdelset(&oset, SIGHUP);
           sigprocmask(SIG_SETMASK, &oset, NULL);

     Another, clearer, alternative is:

           sigset_t set;

           sigemptyset(&set);
           sigaddset(&set, SIGINT);
           sigaddset(&set, SIGHUP);
           sigprocmask(SIG_BLOCK, &set, NULL);

           ...

           sigprocmask(SIG_UNBLOCK, &set, NULL);

     To completely clear the signal mask using  sigsetmask()  one
can do:

           (void) sigsetmask(0);

     Which can be expressed via sigprocmask(2) as:

           sigset_t eset;

           sigemptyset(&eset);
           (void) sigprocmask(SIG_SETMASK, &eset, NULL);

SEE ALSO    [Toc]    [Back]

     kill(2),  sigaction(2),  sigprocmask(2), sigsuspend(2), sigblock(3),
     sigsetops(3), sigvec(3)

HISTORY    [Toc]    [Back]

     The sigsetmask() function call appeared in  4.2BSD  and  has
been deprecated.


OpenBSD      3.6                          March      10,     1991