SIGSETOPS(3) MachTen Programmer’s Manual SIGSETOPS(3)

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

SYNOPSIS
#include <signal.h>

sigemptyset(sigset_t *set)

sigfillset(sigset_t *set)

sigaddset(sigset_t *set, int signo)

sigdelset(sigset_t *set, int signo)

sigismember(sigset_t *set, int signo)

DESCRIPTION
These functions manipulate signal sets stored in a sigset_t. Either
sigemptyset() or sigfillset() must be called for every object of type
sigset_t before any other use of the object.

The sigemptyset() function initializes a signal set to be empty.

The sigfillset() function initializes a signal set to contain all sig-
nals.

The sigaddset() function adds the specified signal signo to the signal
set.

The sigdelset() function deletes the specified signal signo from the sig-
nal set.

The sigismember() function returns whether a specified signal signo is
contained in the signal set.

These functions are provided as macros in the include file <signal.h>.
Actual functions are available if their names are undefined (with #undef
name).

RETURN VALUES
If signo is a valid signal number, the sigismember() function returns 1
if the signal is a member of the set, 0 otherwise. The other functions
return 0 if successful. Otherwise -1 is returned and errno is set appro-
priately.

ERRORS
The following errors may be reported:

[EINVAL] The signal number signo is invalid.

SEE ALSO
kill(2), sigaction(2), sigsuspend(2)

STANDARDS
These functions are defined by IEEE Std1003.1-1988 (‘‘POSIX’’).

4.4BSD June 4, 1993 1