Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
FPCLASSIFY(3)	       FreeBSD 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.	 Similarly, finite() and finitef() are depre-
     cated versions of isfinite().

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     tions, which accepted double arguments; these have	been superseded	by the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.

FreeBSD	11.2		       January 26, 2005			  FreeBSD 11.2

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

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=isinf&sektion=3&manpath=FreeBSD+11.2-RELEASE>

home | help