// Windows NT environment variables, before and after



DEFINE_PRIMITIVE(os_env) 
{ 
    F_CHAR *key = unbox_u16_string(); 
    F_CHAR *value = safe_malloc(MAX_UNICODE_PATH * 2); 
    int ret; 
    ret = GetEnvironmentVariable(key, value, MAX_UNICODE_PATH * 2); 
    if(ret == 0) 
        dpush(F); 
    else 
        dpush(tag_object(from_u16_string(value))); 
    free(value); 
}

DEFINE_PRIMITIVE(os_envs)
{
    GROWABLE_ARRAY(result);
    REGISTER_ROOT(result);

    TCHAR *env = GetEnvironmentStrings();
    TCHAR *finger = env;

    for(;;)
    {
        TCHAR *scan = finger;
        while(*scan != '\0')
            scan++;
        if(scan == finger)
            break;

        CELL string = tag_object(from_u16_string(finger));
        GROWABLE_ARRAY_ADD(result,string);

        finger = scan + 1;
    }

    FreeEnvironmentStrings(env);

    UNREGISTER_ROOT(result);
    GROWABLE_ARRAY_TRIM(result);
    dpush(result);
}
 
DEFINE_PRIMITIVE(set_os_env) 
{ 
    F_CHAR *key = unbox_u16_string(); 
    REGISTER_C_STRING(key); 
    F_CHAR *value = unbox_u16_string(); 
    UNREGISTER_C_STRING(key); 
    if(!SetEnvironmentVariable(key, value)) 
        general_error(ERROR_IO, tag_object(get_error_message()), F, NULL); 
} 
 
DEFINE_PRIMITIVE(unset_os_env) 
{ 
    if(!SetEnvironmentVariable(unbox_u16_string(), NULL) 
        && GetLastError() != ERROR_ENVVAR_NOT_FOUND) 
        general_error(ERROR_IO, tag_object(get_error_message()), F, NULL); 
} 
 
DEFINE_PRIMITIVE(set_os_envs) 
{ 
    not_implemented_error(); 
}