finite3
Classify a floating-point number
Part of fpclassify(3).
Usage
#include <math.h>
int
fpclassify(real-floating x);
int
isfinite(real-floating x);
int
isinf(real-floating x);
int
isnan(real-floating x);
int
isnormal(real-floating x);
Library
Math Library (libm, -lm)
Overview
The fpclassify() macro takes an argument of x and returns one of the following manifest constants.
- FP_INFINITE
-
Indicates that x is an infinite number.
- FP_NAN
-
Indicates that x is not a number (NaN).
- FP_NORMAL
-
Indicates that x is a normalized number.
- FP_SUBNORMAL
-
Indicates that x is a denormalized number.
- FP_ZERO
-
Indicates that x is zero (0 or -0).
The isfinite() macro returns a non-zero value if and only if its argument has a finite (zero, subnormal, or normal) value. The isinf(), isnan(), and isnormal() macros return non-zero if and only if x is an infinity, NaN, or a non-zero normalized number, respectively.
The symbol isnanf() is provided as an alias to isnan() for compatibility, and its use is deprecated. Similarly, finite() and finitef() are deprecated versions of isfinite().
Releases
85 releases since FreeBSD 2.0.5-RELEASE; the text changed 43 times.