memmove_s, wmemmove_s
Moves one buffer to another. These are versions of memmove, wmemmove with security enhancements as described in Security Enhancements in the CRT.
errno_t memmove_s(
void *dest,
size_t numberOfElements,
const void *src,
size_t count
);
errno_t wmemmove_s(
wchar_t *dest,
size_t numberOfElements,
const wchar_t *src,
size_t count
);
Параметры
dest
Destination object.numberOfElements
Size of the destination buffer.src
Source object.count
Number of bytes (memmove_s) or characters (wmemmove_s) to copy.
Возвращаемое значение
Zero if successful; an error code on failure
Error Conditions
dest |
numberOfElements |
src |
Return value |
Contents of dest |
---|---|---|---|---|
NULL |
any |
any |
EINVAL |
not modified |
any |
any |
NULL |
EINVAL |
not modified |
any |
< count |
any |
ERANGE |
not modified |
Заметки
Copies count bytes of characters from src to dest*.* If some regions of the source area and the destination overlap, memmove_s ensures that the original source bytes in the overlapping region are copied before being overwritten.
If dest or if src is a null pointer, or if the destination string is too small, these functions invoke an invalid parameter handler, as described in Parameter Validation . If execution is allowed to continue, these functions return EINVAL and set errno to EINVAL.
Требования
Routine |
Required header |
---|---|
memmove_s |
<string.h> |
wmemmove_s |
<wchar.h> |
For additional compatibility information, see Compatibility in the Introduction.
Пример
// crt_memmove_s.c
//
// The program demonstrates the
// memmove_s function which works as expected
// for moving overlapping regions.
#include <stdio.h>
#include <string.h>
int main()
{
char *str = "0123456789";
printf("Before: %s\n", str);
// Move six bytes from the start of the string
// to a new position shifted by one byte. To protect against
// buffer overrun, the secure version of memmove requires the
// the length of the destination string to be specified.
memmove_s((str + 1), strnlen(str + 1, 10), str, 6);
printf_s(" After: %s\n", str);
}
Output
Before: 0123456789 After: 0012345789
Эквивалент в .NET Framework
См. также
Основные понятия
strncpy_s, _strncpy_s_l, wcsncpy_s, _wcsncpy_s_l, _mbsncpy_s, _mbsncpy_s_l
strncpy, _strncpy_l, wcsncpy, _wcsncpy_l, _mbsncpy, _mbsncpy_l