sigset(3)

NAME

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

SYNOPSIS

     #include <signal.h>

     int sigaddset(sigset_t *set, int sig)
     int sigdelset(sigset_t *set, int sig)
     int sigemptyset(sigset_t *set)
     int sigfillset(sigset_t *set)
     int sigismember(const sigset_t *set, int sig)

DESCRIPTION

     The  system  calls  that  handle  signals,  such  as   sigaction(2)   and
     sigprocmask(2)  use  sets  of  signals  to  keep  a  process  from  being
     interrupted by those signals  while  executing  a  signal  handler  or  a
     critical  code  segment.   These  signal  sets  are  manipulated  by  the
     following functions:

     int sigaddset(sigset_t *set, int sig)
          Add signal sig to the signal set referenced by set.

     int sigdelset(sigset_t *set, int sig)
          Remove signal sig from the signal set referenced by set.

     int sigemptyset(sigset_t *set)
          Initialize the signal set referenced by set to an empty set.

     int sigfillset(sigset_t *set)
          Initialize the signal set referenced by set to an full set, i.e. all
          signals are in the set.

     int sigismember(const sigset_t *set, int sig)
          Return 1 if the signal sig is present in the set referenced by  set,
          0 otherwise.

SEE ALSO

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

DIAGNOSTICS

     All functions  except  sigismember  return  0  on  success.   Sigismember
     returns  0 or 1 on success.  They return -1 with error code EINVAL for an
     invalid signal number.  (They do not use EFAULT for a  bad  set  address,
     but will simply cause a segmentation violation.)

AUTHOR

     Kees J. Bot (kjb@cs.vu.nl)