x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
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():
_BSD_SOURCE || _SVID_SOURCE
isinf():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
_ISOC99_SOURCE;
or cc -std=c99
isinff(), isinfl():
_BSD_SOURCE || _SVID_SOURCE
isnan():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE;
or cc -std=c99
isnanf(), isnanl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
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
Multithreading (see pthreads(7))
The finite(), finitef(), finitel(), isinf(), isinff(), isinfl(),
isnan(), isnanf(), and isnanl() functions are thread-safe.
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 3.69 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
http://www.kernel.org/doc/man-pages/.
2013-07-22 FINITE(3)
Want to link to this manual page? Use this URL:
<http://star2.abcm.com/cgi-bin/bsdi-man?query=finite&sektion=3&manpath=>