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 signals.
The
sigaddset() function adds the specified signal
signo to the signal set.
The
sigdelset() function deletes the specified signal
signo from the signal set.
The
sigismember() function returns whether a specified signal
signo is contained in the signal set.
sigemptyset() and
sigfillset() are provided as macros, but actual functions are available if their names are undefined (with #undef
name).