memcpy, wmemcpy (CRT)

memcpy, wmemcpy

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Microsoft Visual Studio 2005/.NET Framework 2.0

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Run-Time Library Reference

memcpy, wmemcpy

Copies bytes between buffers. These functions are deprecated because more secure versions are available; see memcpy_s, wmemcpy_s.

void *memcpy(
   void *dest,
   const void *src,
   size_t count 
);
wchar_t *wmemcpy(
   wchar_t *dest,
   const wchar_t *src,
   size_t count
);

Parameters

dest: New buffer.

src: Buffer to copy from.

count: Number of characters to copy.

Return Value

The value of dest.

Remarks

memcpy copies count bytes from src to dest; wmemcpy copies count wide characters (two bytes). If the source and destination overlap, the behavior of memcpy is undefined. Use memmove to handle overlapping regions.

Security Note Make sure that the destination buffer is the same size or larger than the source buffer. For more information, see Avoiding Buffer Overruns.

The memcpy and wmemcpy functions will only be deprecated if the constant _CRT_SECURE_DEPRECATE_MEMORY is defined prior to the inclusion statement in order for the functions to be deprecated, such as in the example below:

#define _CRT_SECURE_DEPRECATE_MEMORY
#include <memory.h>

#define _CRT_SECURE_DEPRECATE_MEMORY
#include <wchar.h>

Requirements

Routine	Required header	Compatibility
memcpy	<memory.h> or <string.h>	ANSI, Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003
wmemcpy	<wchar.h>	ANSI, Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003

For additional compatibility information, see Compatibility in the Introduction.

Example

See memmove for a sample of how to use memcpy.

Reference

Buffer Manipulation
_memccpy
memchr, wmemchr
memcmp, wmemcmp
memmove, wmemmove
memset, wmemset
strcpy, wcscpy, _mbscpy
strncpy, _strncpy_l, wcsncpy, _wcsncpy_l, _mbsncpy, _mbsncpy_l