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 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
   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 fpclassify(3).

SEE ALSO
       fpclassify(3)

COLOPHON
       This page is part of release 3.74 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)