This section lists the names for various standard kinds of signals and
describes what kind of event they mean. Each signal name is a macro
which stands for a positive integer—the signal number for that
kind of signal. Your programs should never make assumptions about the
numeric code for a particular kind of signal, but rather refer to them
always by the names defined here. This is because the number for a
given kind of signal can vary from system to system, but the meanings of
the names are standardized and fairly uniform.
The signal names are defined in the header file signal.h.
— Macro: int NSIG
The value of this symbolic constant is the total number of signals
defined. Since the signal numbers are allocated consecutively,
NSIG is also one greater than the largest defined signal number.
