sigsetops(3P) INTERACTIVE UNIX System (POSIX) sigsetops(3P)
NAME
sigsetops, sigaddset, sigdelset, sigemptyset, sigfillset,
sigismember - manipulate signal sets
SYNOPSIS
#include <signal.h>
int sigemptyset (set)
sigset_t*set;
int sigfillset (set)
sigset_t*set;
int sigaddset (set, signo)
sigset_t*set;
intsigno;
int sigdelset (set, signo)
sigset_t*set;
intsigno;
int sigismember (set, signo)
sigset_t*set;
intsigno;
DESCRIPTION
The sigsetops primitives manipulate sets of signals. They
operate on data objects addressable by the application, not
on any set of signals known to the system, such as the set
blocked from delivery to a process or the set pending for a
process.
The sigemptyset() function initializes the signal set
pointed to by the argument set, such that all signals
defined in this standard are excluded.
The sigfillset() function initializes the signal set pointed
to by the argument set, such that all signals defined in
this standard are included.
Applications must call either sigemptyset() or sigfillset()
at least once for each object of type sigset_t prior to any
other use of that object. If such an object is not initial-
ized in this way, but is nevertheless supplied as an argu-
ment to any of the sigaddset(), sigdelset(), sigismember(),
sigaction(), sigprocmask(), sigpending(), or sigsuspend()
functions, the results are undefined.
The sigaddset() and sigdelset() functions respectively add
and delete the individual signal specified by the value of
the argument signo from the signal set pointed to by the
argument set.
The sigismember() function tests whether the signal
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sigsetops(3P) INTERACTIVE UNIX System (POSIX) sigsetops(3P)
specified by the value of the argument signo is a member of
the set pointed to by the argument set.
RETURNS
Upon successful completion, the sigismember() function
returns a value of one if the specified signal is a member
of the specified set, or a value of zero if it is not. Upon
successful completion, the other functions return a value of
zero. For all the above functions, if an error is detected,
a value of -1 is returned, and errno is set to indicate the
error.
ERROR MESSAGES
For each of the following conditions, if the condition is
detected, the sigaddset(), sigdelset(), and sigismember()
functions shall return -1 and set errno to EINVAL.
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