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
| | #include <stdlib.h>
#include <string.h>
#include <errno.h>
char *__strchrnul(const char *, int);
int __putenv(char *, size_t, char *);
void __env_change(char *p, char *r)
{
static char **env_alloced;
static size_t env_alloced_n;
for (size_t i=0; i < env_alloced_n; i++)
if (env_alloced[i] == p) {
env_alloced[i] = r;
free(p);
return;
}
if (!r) return;
char **new_ea = realloc(env_alloced, sizeof *new_ea * (env_alloced_n+1));
if (!new_ea) return;
new_ea[env_alloced_n++] = r;
env_alloced = new_ea;
}
int setenv(const char *var, const char *value, int overwrite)
{
char *s;
size_t l1 = __strchrnul(var, '=') - var, l2;
if (!l1 || var[l1]) {
errno = EINVAL;
return -1;
}
if (!overwrite && getenv(var)) return 0;
l2 = strlen(value);
s = malloc(l1+l2+2);
if (!s) return -1;
memcpy(s, var, l1);
s[l1] = '=';
memcpy(s+l1+1, value, l2+1);
return __putenv(s, l1, s);
}
|