xfree86 man page for finite

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
       otherwise.

       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 fpclassify(3).

SEE ALSO

       fpclassify(3)

COLOPHON

       This  page is part of release 4.15 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/.

								    2017-09-15								 FINITE(3)