Category : C Source Code
Archive   : ECSTR.ZIP
Filename : MEMCPY.C

Output of file : MEMCPY.C contained in archive : ECSTR.ZIP
/* File : memcpy.c
Author : Richard A. O'Keefe.
Updated: 25 May 1984
Defines: memcpy()

memcpy(dst, src, len)
moves len bytes from src to dst. The result is dst. This is not
the same as strncpy or strnmov, while move a maximum of len bytes
and stop early if they hit a NUL character. This moves len bytes
exactly, no more, no less. See also bcopy() and bmove() which do
not return a value but otherwise do the same job.

Note: the VAX assembly code version can only handle 0 <= len < 2^16.
It is presented for your interest and amusement.

#include "strings.h"

#if VaxAsm

char *memcpy(dst, src, len)
char *dst, *src;
int len;
asm("movc3 12(ap),*8(ap),*4(ap)");
return dst;

#else ~VaxAsm

char *memcpy(dst, src, len)
char *dst;
register char *src;
register int len;
register char *d;

for (d = dst; --len >= 0; *d++ = *src++) ;
return dst;

#endif VaxAsm

  3 Responses to “Category : C Source Code
Archive   : ECSTR.ZIP
Filename : MEMCPY.C

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: