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| | #include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "libc.h"
char *__strchrnul(const char *, int);
static void dummy(char *p, char *r) {}
weak_alias(dummy, __env_change);
int unsetenv(const char *name)
{
size_t l = __strchrnul(name, '=') - name;
if (!l || name[l]) {
errno = EINVAL;
return -1;
}
if (!__environ) return 0;
for (char **e = __environ; *e; e++)
while (*e && !strncmp(name, *e, l) && l[*e] == '=') {
char **ee = e, *tmp = *e;
do *ee = *(ee+1);
while (*++ee);
__env_change(tmp, 0);
}
return 0;
}
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