CopyMemory

Copies a block of memory from one location to another.

Syntax

C++

void CopyMemory(
  __in  PVOID Destination,
  __in  const VOID *Source,
  __in  SIZE_T Length
);

Parameters

Destination [in]

A pointer to the starting address of the copied block's destination.

Source [in]

A pointer to the starting address of the block of memory to copy.

Length [in]

The size of the block of memory to copy, in bytes.

Examples

The following code example shows a safer way to use CopyMemory. Alternatively, you could use the memcpy_s or wmemcpy_s function.

C++

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

#define BUFFER_SIZE 1024
#define COPY_SIZE 512

/*
   MyCopyMemory - A wrapper for CopyMemory

   buf     - destination buffer
   pbData  - source buffer
   cbData  - size of block to copy, in bytes
   bufsize - size of the destination buffer
*/

void MyCopyMemory(TCHAR *buf, TCHAR *pbData, SIZE_T cbData, SIZE_T bufsize) 
{
    CopyMemory(buf, pbData, min(cbData,bufsize));
}

void main()
{
    TCHAR buf[BUFFER_SIZE] = TEXT("This is the destination");
    TCHAR pbData[BUFFER_SIZE] = TEXT("This is the source");

    MyCopyMemory(buf, pbData, COPY_SIZE*sizeof(TCHAR), BUFFER_SIZE*sizeof(TCHAR));

    _tprintf(TEXT("Destination buffer contents: %s\n"), buf);
}