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FPCLASSIFY(3)		 BSD Library Functions Manual		 FPCLASSIFY(3)

NAME
     fpclassify, isfinite, isinf, isnan, isnormal -- classify a	floating-point
     number

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     int
     fpclassify(real-floating x);

     int
     isfinite(real-floating x);

     int
     isinf(real-floating x);

     int
     isnan(real-floating x);

     int
     isnormal(real-floating x);

DESCRIPTION
     The fpclassify() macro takes an argument of x and returns one of the fol-
     lowing manifest constants.

     FP_INFINITE   Indicates that x is an infinite number.

     FP_NAN	   Indicates that x is not a number (NaN).

     FP_NORMAL	   Indicates that x is a normalized number.

     FP_SUBNORMAL  Indicates that x is a denormalized number.

     FP_ZERO	   Indicates that x is zero (0 or -0).

     The isfinite() macro returns a non-zero value if and only if its argument
     has a finite (zero, subnormal, or normal) value.  The isinf(), isnan(),
     and isnormal() macros return non-zero if and only if x is an infinity,
     NaN, or a non-zero	normalized number, respectively.

     The symbol	isnanf() is provided as	an alias to isnan() for	compatibility,
     and its use is deprecated.

SEE ALSO
     isgreater(3), math(3), signbit(3)

STANDARDS
     The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros
     conform to	ISO/IEC	9899:1999 ("ISO	C99").

HISTORY
     The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros
     were added	in FreeBSD 5.1.	 3BSD introduced isinf() and isnan() func-
     tions, which accepted double arguments; these have	been superseded	by the
     macros described above.

BSD				 July 8, 2004				   BSD

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | SEE ALSO | STANDARDS | HISTORY

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