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/*
* __put_env.c - common code for putenv() and setenv()
*/
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "env.h"
static size_t __environ_size;
static char **__environ_alloc;
/* str should be a duplicated version of the input string;
len is the length of the key including the = sign */
int __put_env(char *str, size_t len, int overwrite)
{
static char *const null_environ = { NULL };
char **p, *q;
char **newenv;
size_t n;
if (!environ)
environ = (char **)null_environ;
n = 1; /* Include space for final NULL */
for (p = environ; (q = *p); p++) {
n++;
if (!strncmp(q, str, len)) {
if (!overwrite)
free(str);
else
*p = str; /* Possible memory leak... */
return 0;
}
}
if (__environ_alloc && environ != __environ_alloc) {
free(__environ_alloc);
__environ_alloc = NULL;
}
/* Need to extend the environment */
if (n < __environ_size) {
p[1] = NULL;
*p = str;
return 0;
} else {
if (__environ_alloc) {
newenv =
realloc(__environ_alloc,
(__environ_size << 1) * sizeof(char *));
if (!newenv)
return -1;
__environ_size <<= 1;
} else {
/* Make a reasonable guess how much more space
we need */
size_t newsize = n + 32;
newenv = malloc(newsize * sizeof(char *));
if (!newenv)
return -1;
memcpy(newenv, environ, n * sizeof(char *));
__environ_size = newsize;
}
newenv[n-1] = str; /* Old NULL position */
newenv[n] = NULL;
environ = newenv;
}
return 0;
}
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