Header File 

float.h 

Category 

Math Routines 

Prototype 

int _finite(double d); 

int _finitel(long double ld); 

Description 

Determines whether a given double-precision floating point value d is finite. 

_finitel is the long double version; it takes a long double argument. 

Return Value 

Returns non-zero if the argument is finite, and 0 if it is not. 

Portability