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



NAME
       finite,	finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl
       - BSD floating-point classification functions

SYNOPSIS
       #include <math.h>

       int finite(double x);
       int finitef(float x);
       int finitel(long double x);

       int isinf(double x);
       int isinff(float x);
       int isinfl(long double x);

       int isnan(double x);
       int isnanf(float x);
       int isnanl(long double x);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       finite(), finitef(), finitel():
	   /* Glibc since 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       isinf():
	   _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE
	       || /* Glibc since 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       isinff(), isinfl():
	   /* Glibc since 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       isnan():
	   _XOPEN_SOURCE || _ISOC99_SOURCE
	       || /* Glibc since 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       isnanf(), isnanl():
	   _XOPEN_SOURCE >= 600
	       || /* Glibc since 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       The finite(), finitef(), and finitel() functions return a nonzero value
       if x is neither infinite nor a "not-a-number" (NaN) value, and 0 other-
       wise.

       The isnan(), isnanf(), and isnanl() functions return a nonzero value if
       x is a NaN value, and 0 otherwise.

       The isinf(), isinff(), and isinfl() functions return 1 if x is positive
       infinity, -1 if x is negative infinity, and 0 otherwise.

ATTRIBUTES
       For  an	explanation  of	 the  terms  used   in	 this	section,   see
       attributes(7).

       +--------------------------------+---------------+---------+
       |Interface			| Attribute	| Value	  |
       +--------------------------------+---------------+---------+
       |finite(), finitef(), finitel(), | Thread safety | MT-Safe |
       |isinf(), isinff(), isinfl(),	|		|	  |
       |isnan(), isnanf(), isnanl()	|		|	  |
       +--------------------------------+---------------+---------+
NOTES
       Note that these functions are obsolete.	C99 defines macros isfinite(),
       isinf(), and isnan() (for all types) replacing them.  Further note that
       the C99 isinf() has weaker guarantees on the return value.  See fpclas-
       sify(3).

SEE ALSO
       fpclassify(3)

COLOPHON
       This page is part of release 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



				  2016-03-15			     FINITE(3)