isfinite(3) - NetBSD Manual Pages

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ISFINITE(3)             NetBSD Library Functions Manual            ISFINITE(3)


NAME

     isfinite -- test for finite value


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <math.h>

     int
     isfinite(real-floating x);


DESCRIPTION

     The isfinite() determines whether its argument x has a finite value.  An
     argument represented in a format wider than its semantic type is con-
     verted to its semantic type first.  The determination is then based on
     the type of the argument.

   IEEE 754
     It is determined whether the value of x is zero, subnormal, or normal,
     and neither infinite nor NaN.

   VAX
     It is determined whether the value of x is true zero or finite, and nei-
     ther dirty zero nor ROP.


RETURN VALUES

     The isfinite() macro returns a non-zero value if the value of x is
     finite.  Otherwise 0 is returned.


ERRORS

     No errors are defined.


SEE ALSO

     finite(3), fpclassify(3), isnormal(3), math(3), signbit(3)


STANDARDS

     The isfinite() macro conforms to ISO/IEC 9899:1999 (``ISO C99'').

NetBSD 6.1.2                    August 6, 2011                    NetBSD 6.1.2