memcpy_s, wmemcpy_s
Copies bytes between buffers. These are versions of memcpy, wmemcpy with security enhancements as described in Security Features in the CRT.
errno_t memcpy_s( void *dest, size_t numberOfElements, const void *src, size_t count ); errno_t wmemcpy_s( wchar_t *dest, size_t numberOfElements, const wchar_t *src, size_t count );
memcpy_s copies count bytes from src to dest; wmemcpy_s copies count wide characters (two bytes). If the source and destination overlap, the behavior of memcpy_s is undefined. Use memmove_s to handle overlapping regions.
These functions validate their parameters. If dest or src is a null pointer, or numberOfElements is too small for the buffer, these functions invoke the invalid parameter handler, as described in Parameter Validation. If execution is allowed to continue, these functions return EINVAL and set errno to EINVAL.
|
Routine |
Required header |
|---|---|
|
memcpy_s |
<memory.h> or <string.h> |
|
wmemcpy_s |
<wchar.h> |
For additional compatibility information, see Compatibility in the Introduction.
// crt_memcpy_s.c
// Copy memory in a more secure way.
#include <memory.h>
#include <stdio.h>
int main()
{
int a1[10], a2[100], i;
errno_t err;
// Populate a2 with squares of integers
for (i = 0; i < 100; i++)
{
a2[i] = i*i;
}
// Tell memcpy_s to copy 10 ints (40 bytes), giving
// the size of the a1 array (also 40 bytes).
err = memcpy_s(a1, sizeof(a1), a2, 10 * sizeof (int) );
if (err)
{
printf("Error executing memcpy_s.\n");
}
else
{
for (i = 0; i < 10; i++)
printf("%d ", a1[i]);
}
printf("\n");
}
0 1 4 9 16 25 36 49 64 81
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
