isinff(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 4.09 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)

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