third_party/ulib/musl/src/env/putenv.c

#include <stdlib.h>
#include <string.h>

#include "libc.h"
#include "env_impl.h"

char** __env_map;

int __putenv(char* s, int a) {
    int i = 0, j = 0;
    char* z = strchr(s, '=');
    char** newenv = 0;
    char** newmap = 0;
    static char** oldenv;

    if (!z)
        return unsetenv(s);
    if (z == s)
        return -1;
    for (; __environ[i] && memcmp(s, __environ[i], z - s + 1); i++)
        ;
    if (a) {
        if (!__env_map) {
            __env_map = calloc(2, sizeof(char*));
            if (__env_map)
                __env_map[0] = s;
        } else {
            for (; __env_map[j] && __env_map[j] != __environ[i]; j++)
                ;
            if (!__env_map[j]) {
                newmap = realloc(__env_map, sizeof(char*) * (j + 2));
                if (newmap) {
                    __env_map = newmap;
                    __env_map[j] = s;
                    __env_map[j + 1] = NULL;
                }
            } else {
                free(__env_map[j]);
                __env_map[j] = s;
            }
        }
    }
    if (!__environ[i]) {
        newenv = malloc(sizeof(char*) * (i + 2));
        if (!newenv) {
            if (a && __env_map)
                __env_map[j] = 0;
            return -1;
        }
        memcpy(newenv, __environ, sizeof(char*) * i);
        newenv[i] = s;
        newenv[i + 1] = 0;
        __environ = newenv;
        free(oldenv);
        oldenv = __environ;
    }

    __environ[i] = s;
    return 0;
}

int putenv(char* s) {
    return __putenv(s, 0);
}