ISFINITE(3) BSD Programmer's Manual ISFINITE(3)

**isfinite** - test for finite value

libc

**#include <math.h>**
*int*
**isfinite**(*real-floating x*);

The **isfinite**() determines whether its argument *x* has a finite value. An
argument represented in a format wider than its semantic type is convert-
ed to its semantic type first. The determination is then based on the
type of the argument.

It is determined whether the value of *x* is zero, subnormal, or normal,
and neither infinite nor NaN.

It is determined whether the value of *x* is true zero or finite, and nei-
ther dirty zero nor ROP.

The **isfinite**() macro returns a non-zero value if the value of *x* is fin-
ite. Otherwise 0 is returned.

No errors are defined.

fpclassify(3), isnormal(3), math(3), signbit(3)

The **isfinite**() macro conforms to ISO/IEC 9899:1999 ("ISO C99").
MirBSD #10-current October 29, 2003 1