ISFINITE(3) Library Functions Manual ISFINITE(3)

NAME

isfinitetest for finite value

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <math.h>

int
isfinite(real-floating x);

DESCRIPTION

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

IEEE 754

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

VAX

It is determined whether the value of x is true zero or finite, and neither dirty zero nor ROP.

RETURN VALUES

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

ERRORS

No errors are defined.

SEE ALSO

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

STANDARDS

The isfinite() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
August 6, 2011 NetBSD 6.1