linux man page for infnan

INFNAN(3)						     Linux Programmer's Manual							 INFNAN(3)

NAME
       infnan - deal with infinite or not-a-number (NaN) result

SYNOPSIS
       #include <math.h>

       double infnan(int error);

       Link with -lm.

DESCRIPTION
       The  infnan()  function returns a suitable value for infinity and "not-a-number" (NaN) results.	The value of error can be ERANGE to repre-
       sent infinity or anything else to represent NaN.  errno is also set.

RETURN VALUE
       If error is ERANGE (Infinity), HUGE_VAL is returned.

       If error is -ERANGE (-Infinity), -HUGE_VAL is returned.

       If error is anything else, NAN is returned.

ERRORS
       EDOM   The value of error is "not-a-number" (NaN).

       ERANGE The value of error is positive infinity or negative infinity.

CONFORMING TO
       4.3BSD.

NOTES
       This obsolete function was provided in libc4 and libc5, but is not available in glibc2.

GNU
								    1993-06-02								 INFNAN(3)