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