ceil(3) — Справочная страница Linux

ceil(3)                 Library Functions Manual                 ceil(3)

ИМЯ

       ceil, ceilf, ceill - ceiling function: smallest integral value
       not less than argument

БИБЛИОТЕКА

       Math library (libm, -lm)

СИНТАКСИС

       #include <math.h>

       double ceil(double x);
       float ceilf(float x);
       long double ceill(long double x);

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

       ceilf(), ceill():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

ОПИСАНИЕ

       These functions return the smallest integral value that is not
       less than x.

       For example, ceil(0.5) is 1.0, and ceil(-0.5) is 0.0.

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       These functions return the ceiling of x.

       If x is integral, +0, -0, NaN, or infinite, x itself is returned.

ОШИБКИ

       No errors occur.

АТРИБУТЫ

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ ceil(), ceilf(), ceill()            │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

СТАНДАРТЫ

       C11, POSIX.1-2008.

ИСТОРИЯ

       C99, POSIX.1-2001.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

       SUSv2 and POSIX.1-2001 contain text about overflow (which might
       set errno to ERANGE, or raise an FE_OVERFLOW exception).  In
       practice, the result cannot overflow on any current machine, so
       this error-handling stuff was just nonsense.  (More precisely,
       overflow can happen only when the maximum value of the exponent
       is smaller than the number of mantissa bits.  For the IEEE-754
       standard 32-bit and 64-bit floating-point numbers the maximum
       value of the exponent is 127 (respectively, 1023), and the number
       of mantissa bits including the implicit bit is 24 (respectively,
       53).)  This was removed in POSIX.1-2008.

       The integral value returned by these functions may be too large
       to store in an integer type (int, long, etc.).  To avoid an
       overflow, which will produce undefined results, an application
       should perform a range check on the returned value before
       assigning it to an integer type.

СМОТРИТЕ ТАКЖЕ

       floor(3), lrint(3), nearbyint(3), rint(3), round(3), trunc(3)

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
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       man-pages@man7.org

Linux man-pages 6.9.1          2024-06-16                        ceil(3)

Страницы, которые ссылаются на эту страницу: abs(3), fabs(3), floor(3), lrint(3), lround(3), rint(3), round(3), roundup(3), trunc(3)