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   strndup    ( 3 )

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Имя (Name)

strdup, strndup, strdupa, strndupa - duplicate a string

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Синопсис (Synopsis)

#include <string.h>

       char *strdup(const char *s);

       char *strndup(const char *s, size_t n);
       char *strdupa(const char *s);
       char *strndupa(const char *s, size_t n);

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

       strdup():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
               || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

       strndup():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _GNU_SOURCE

       strdupa(), strndupa():
           _GNU_SOURCE

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Описание (Description)

The strdup() function returns a pointer to a new string which is
       a duplicate of the string s.  Memory for the new string is
       obtained with malloc(3), and can be freed with free(3).

       The strndup() function is similar, but copies at most n bytes.
       If s is longer than n, only n bytes are copied, and a terminating
       null byte ('\0') is added.

       strdupa() and strndupa() are similar, but use alloca(3) to
       allocate the buffer.  They are available only when using the GNU
       GCC suite, and suffer from the same limitations described in
       alloca(3).

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Возвращаемое значение (Return value)

On success, the strdup() function returns a pointer to the
       duplicated string.  It returns NULL if insufficient memory was
       available, with errno set to indicate the error.

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Ошибки (Error)

ENOMEM Insufficient memory available to allocate duplicate
              string.

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Атрибуты (Attributes)

For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │Interface                             │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │strdup(), strndup(), strdupa(),       │ Thread safety │ MT-Safe │
       │strndupa()                            │               │         │
       └──────────────────────────────────────┴───────────────┴─────────┘

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Стандарты (Conforming to)

strdup() conforms to SVr4, 4.3BSD, POSIX.1-2001.  strndup()
       conforms to POSIX.1-2008.  strdupa() and strndupa() are GNU
       extensions.

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Смотри также (See also)

alloca(3), calloc(3), free(3), malloc(3), realloc(3), string(3),
       wcsdup(3)

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