1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
/* inststr.c ... stolen from bdupdate.c, which stole it from perl 4.
* Theft by C. Scott Ananian <cananian@alumni.princeton.edu>
* Modified similarly to perl 5.8.3's alignment-checking code
8 by Paul Howarth <paul@city-fan.org>
*
* $Id: inststr.c,v 1.3 2004/06/08 23:40:14 quozl Exp $
*/
#include <string.h>
#define PTRSIZE sizeof(void *)
typedef unsigned long UL;
void
inststr(int argc, char **argv, char **environ, char *src)
{
if (strlen(src) <= strlen(argv[0]))
{
char *ptr;
for (ptr = argv[0]; *ptr; *(ptr++) = '\0');
strcpy(argv[0], src);
} else
{
/* Stolen from the source to perl 4.036 (assigning to $0) */
/* Modified to allow for aligned array members, assuming */
/* no system has something bizarre like the argv[] */
/* interleaved with some other data. Also allow for argv */
/* array having higher numbered elements lower in memory */
/* than lower numbered elements. */
char *ptr, *ptr2;
int count;
UL mask = ~(UL)(PTRSIZE == 4 ? 3 : PTRSIZE == 8 ? 7 : PTRSIZE == 16 ? 15 : 0);
int aligned = (mask < ~(UL)0) && (((UL)(argv[0]) & mask) == (UL)(argv[0]));
ptr = argv[0] + strlen(argv[0]);
if (argv[argc - 1] >= argv[1]) {
/* argv pointers in ascending memory order */
for (count = 1; count < argc; count++) {
if (argv[count] == ptr + 1
||
(aligned && argv[count] > ptr && argv[count] <= (char *)((UL)(ptr + PTRSIZE) & mask))
) {
ptr = argv[count] + strlen(argv[count]);
}
}
} else
{
/* sometimes the argv pointers go down in memory rather than up */
for (count = argc - 1; count > 0; count--) {
if (argv[count] == ptr + 1
||
(aligned && argv[count] > ptr && argv[count] <= (char *)((UL)(ptr + PTRSIZE) & mask))
) {
ptr = argv[count] + strlen(argv[count]);
}
}
}
for (count = 0; environ[count]; count++) {
if (environ[count] == ptr + 1
||
(aligned && environ[count] > ptr && environ[count] <= (char *)((UL)(ptr + PTRSIZE) & mask))
) {
ptr = environ[count] + strlen(environ[count]);
}
}
count = 0;
for (ptr2 = argv[0]; ptr2 <= ptr; ptr2++) {
*ptr2 = '\0';
count++;
}
strncpy(argv[0], src, count);
}
}
|
