static const char *const safe_env_lst[] =
{
    /* variable name starts with */
    "HTTP_",
    "SSL_",

    /* variable name is */
    "AUTH_TYPE=",
    "CONTENT_LENGTH=",
    "CONTENT_TYPE=",
    "DATE_GMT=",
    "DATE_LOCAL=",
    "DOCUMENT_NAME=",
    "DOCUMENT_PATH_INFO=",
    "DOCUMENT_ROOT=",
    "DOCUMENT_URI=",
    "GATEWAY_INTERFACE=",
    "HTTPS=",
    "LAST_MODIFIED=",
    "PATH_INFO=",
    "PATH_TRANSLATED=",
    "QUERY_STRING=",
    "QUERY_STRING_UNESCAPED=",
    "REMOTE_ADDR=",
    "REMOTE_HOST=",
    "REMOTE_IDENT=",
    "REMOTE_PORT=",
    "REMOTE_USER=",
    "REDIRECT_HANDLER=",
    "REDIRECT_QUERY_STRING=",
    "REDIRECT_REMOTE_USER=",
    "REDIRECT_STATUS=",
    "REDIRECT_URL=",
    "REQUEST_METHOD=",
    "REQUEST_URI=",
    "SCRIPT_FILENAME=",
    "SCRIPT_NAME=",
    "SCRIPT_URI=",
    "SCRIPT_URL=",
    "SERVER_ADMIN=",
    "SERVER_NAME=",
    "SERVER_ADDR=",
    "SERVER_PORT=",
    "SERVER_PROTOCOL=",
    "SERVER_SIGNATURE=",
    "SERVER_SOFTWARE=",
    "UNIQUE_ID=",
    "USER_NAME=",
    "TZ=",
    NULL
};