SIGSETOPS(3-POSIX)  RISC/os Reference Manual   SIGSETOPS(3-POSIX)



NAME
     sigemptyset, sigfillset, sigaddset, sigdelset, sigismember
      - manipulate signal sets

SYNOPSIS
     #include <signal.h>

     int sigemptyset(set)
     sigsett *set;

     int sigfillset(set)
     sigsett *set;

     int sigaddset(set, signo)
     sigsett *set;
     int signo;

     int sigdelset(set, signo)
     sigsett *set;
     int signo;

     int sigismember(set, signo)
     sigsett *set;
     int signo;

DESCRIPTION
     These routines manipulate sets of signals.  They operate on
     data objects addressable by the program, not on any set of
     signals known to the system, such as the sets of blocked and
     pending signals for a process.

     sigemptyset initializes the signal set pointed to by set
     such that all signals are excluded.

     sigfillset initializes the signal set pointed to by set such
     that all signals are included.

     Either sigemptyset or sigfillset must be called at least
     once for each object of type sigset_t prior to any other use
     of that object.

     sigaddset and sigdelset respectively add and delete the sig-
     nal indicated by signo from the signal set pointed to by
     set.

     sigismember tests whether the signal indicated by signo is a
     member of the set pointed to by set.

RETURN VALUES
     Upon successful completion, sigismember returns 1 if the
     specified signal is a member of the specified set and 0 if
     it is not.  Upon successful completion, sigemptyset,



                         Printed 1/15/91                   Page 1

SIGSETOPS(3-POSIX)  RISC/os Reference Manual   SIGSETOPS(3-POSIX)



     sigfillset, sigaddset, and sigdelset return 0.  If any of
     the above functions fail, -1 is returned and errno is set to
     indicate the error.

ERRORS
     If any of the following conditions occur, sigaddset, sigdel-
     set, and sigismember return -1 and set errno to the
     corresponding value:

     [EINVAL]            The value of signo is invalid.

     If any of the following conditions occur, the above func-
     tions return -1 and set errno to the corresponding value:

     [EFAULT]            set points outside the process' allo-
                         cated address space.

SEE ALSO
     sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2).




































 Page 2                  Printed 1/15/91