isinf

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  nega-
       tive  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
       finite or is not a "not-a-number" (NaN) value, and 0  oth-
       erwise.

CONFORMING TO

       BSD 4.3