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strcpy(3)               Library Functions Manual               strcpy(3)

ИМЯ

       stpcpy, strcpy, strcat - copy or catenate a string

БИБЛИОТЕКА

       Standard C library (libc, -lc)

СИНТАКСИС

       #include <string.h>

       char *stpcpy(char *restrict dst, const char *restrict src);
       char *strcpy(char *restrict dst, const char *restrict src);
       char *strcat(char *restrict dst, const char *restrict src);

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

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

ОПИСАНИЕ

       stpcpy()
       strcpy()
              These functions copy the string pointed to by src, into a
              string at the buffer pointed to by dst.  The programmer is
              responsible for allocating a destination buffer large
              enough, that is, strlen(src) + 1.  For the difference
              between the two functions, see RETURN VALUE.

       strcat()
              This function catenates the string pointed to by src,
              after the string pointed to by dst (overwriting its
              terminating null byte).  The programmer is responsible for
              allocating a destination buffer large enough, that is,
              strlen(dst) + strlen(src) + 1.

       An implementation of these functions might be:

           char *
           stpcpy(char *restrict dst, const char *restrict src)
           {
               char  *p;

               p = mempcpy(dst, src, strlen(src));
               *p = '\0';

               return p;
           }

           char *
           strcpy(char *restrict dst, const char *restrict src)
           {
               stpcpy(dst, src);
               return dst;
           }

           char *
           strcat(char *restrict dst, const char *restrict src)
           {
               stpcpy(dst + strlen(dst), src);
               return dst;
           }

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       stpcpy()
              This function returns a pointer to the terminating null
              byte of the copied string.

       strcpy()
       strcat()
              These functions return dst.

АТРИБУТЫ

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

СТАНДАРТЫ

       stpcpy()
              POSIX.1-2008.

       strcpy()
       strcat()
              C11, POSIX.1-2008.

СТАНДАРТЫ

       stpcpy()
              POSIX.1-2008.

       strcpy()
       strcat()
              POSIX.1-2001, C89, SVr4, 4.3BSD.

ЗАМЕЧАНИЯ

       The strings src and dst may not overlap.

       If the destination buffer is not large enough, the behavior is
       undefined.  See _FORTIFY_SOURCE in feature_test_macros(7).

       strcat() can be very inefficient.  Read about Shlemiel the
       painter 
       ⟨https://www.joelonsoftware.com/2001/12/11/back-to-basics/⟩.

ПРИМЕРЫ

       #include <err.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>

       int
       main(void)
       {
           char    *p;
           char    *buf1;
           char    *buf2;
           size_t  len, maxsize;

           maxsize = strlen("Hello ") + strlen("world") + strlen("!") + 1;
           buf1 = malloc(sizeof(*buf1) * maxsize);
           if (buf1 == NULL)
               err(EXIT_FAILURE, "malloc()");
           buf2 = malloc(sizeof(*buf2) * maxsize);
           if (buf2 == NULL)
               err(EXIT_FAILURE, "malloc()");

           p = buf1;
           p = stpcpy(p, "Hello ");
           p = stpcpy(p, "world");
           p = stpcpy(p, "!");
           len = p - buf1;

           printf("[len = %zu]: ", len);
           puts(buf1);  // "Hello world!"
           free(buf1);

           strcpy(buf2, "Hello ");
           strcat(buf2, "world");
           strcat(buf2, "!");
           len = strlen(buf2);

           printf("[len = %zu]: ", len);
           puts(buf2);  // "Hello world!"
           free(buf2);

           exit(EXIT_SUCCESS);
       }

СМОТРИТЕ ТАКЖЕ

       strdup(3), string(3), wcscpy(3), string_copying(7)

КОЛОФОН

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       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
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       man-pages@man7.org

Linux man-pages 6.9.1          2024-06-15                      strcpy(3)

Страницы, которые ссылаются на эту страницу: bcopy(3), memccpy(3), memcpy(3), memmove(3), string(3), wcpcpy(3), wcscat(3), wcscpy(3), feature_test_macros(7), signal-safety(7), string_copying(7)