NAME

       isinf, isnan, finite - test for infinity or not-a-number (NaN)

SYNOPSIS

       #include <math.h>

       int isinf(double value);

       int isnan(double value);

       int finite(double value);

DESCRIPTION

       The  isinf()  function  returns  -1  if  value  represents  negative  infinity, 1 if value
       represents positive infinity, and 0 otherwise.

       The isnan() function returns a non-zero value if value  is  "not-a-number"  (NaN),  and  0
       otherwise.

       The  finite() function returns a non-zero value if value is neither infinite nor a "not-a-
       number" (NaN) value, and 0 otherwise.

CONFORMING TO

       BSD 4.3