isnan

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



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.

NOTE
       C99 provides additional macros, such as the type-independent
       fpclassify(), isinf() and isnan().

CONFORMING TO
       BSD 4.3

SEE ALSO
       fpclassify(3)




                                  2002-07-27                          ISINF(3)