1 /*
2 FUNCTION
3 <<memmove>>---move possibly overlapping memory
4
5 INDEX
6 memmove
7
8 ANSI_SYNOPSIS
9 #include <string.h>
10 void *memmove(void *<[dst]>, const void *<[src]>, size_t <[length]>);
11
12 TRAD_SYNOPSIS
13 #include <string.h>
14 void *memmove(<[dst]>, <[src]>, <[length]>)
15 void *<[dst]>;
16 void *<[src]>;
17 size_t <[length]>;
18
19 DESCRIPTION
20 This function moves <[length]> characters from the block of
21 memory starting at <<*<[src]>>> to the memory starting at
22 <<*<[dst]>>>. <<memmove>> reproduces the characters correctly
23 at <<*<[dst]>>> even if the two areas overlap.
24
25
26 RETURNS
27 The function returns <[dst]> as passed.
28
29 PORTABILITY
30 <<memmove>> is ANSI C.
31
32 <<memmove>> requires no supporting OS subroutines.
33
34 QUICKREF
35 memmove ansi pure
36 */
37
38 void*
39 memmove (void *dst_void, const void *src_void, long length)
40 {
41 char *dst = dst_void;
42 const char *src = src_void;
43
44 if (src < dst && dst < src + length)
45 {
46 /* Have to copy backwards */
47 src += length;
48 dst += length;
49 while (length--)
50 {
51 *--dst = *--src;
52 }
53 }
54 else
55 {
56 while (length--)
57 {
58 *dst++ = *src++;
59 }
60 }
61
62 return dst_void;
63 }