atoi(3) — Справочная страница Linux

atoi(3)                 Library Functions Manual                 atoi(3)

ИМЯ

       atoi, atol, atoll - convert a string to an integer

БИБЛИОТЕКА

       Standard C library (libc, -lc)

СИНТАКСИС

       #include <stdlib.h>

       int atoi(const char *nptr);
       long atol(const char *nptr);
       long long atoll(const char *nptr);

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

       atoll():
           _ISOC99_SOURCE
               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

ОПИСАНИЕ

       The atoi() function converts the initial portion of the string
       pointed to by nptr to int.  The behavior is the same as

           strtol(nptr, NULL, 10);

       except that atoi() does not detect errors.

       The atol() and atoll() functions behave the same as atoi(),
       except that they convert the initial portion of the string to
       their return type of long or long long.

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       The converted value or 0 on error.

АТРИБУТЫ

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

ВЕРСИИ

       POSIX.1 leaves the return value of atoi() on error unspecified.
       On glibc, musl libc, and uClibc, 0 is returned on error.

СТАНДАРТЫ

       C11, POSIX.1-2008.

ИСТОРИЯ

       C99, POSIX.1-2001, SVr4, 4.3BSD.

       C89 and POSIX.1-1996 include the functions atoi() and atol()
       only.

ОШИБКИ

       errno is not set on error so there is no way to distinguish
       between 0 as an error and as the converted value.  No checks for
       overflow or underflow are done.  Only base-10 input can be
       converted.  It is recommended to instead use the strtol() and
       strtoul() family of functions in new programs.

СМОТРИТЕ ТАКЖЕ

       atof(3), strtod(3), strtol(3), strtoul(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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       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                        atoi(3)

Страницы, которые ссылаются на эту страницу: atof(3), form_field_validation(3x), strtod(3), strtol(3), strtoul(3)