Someone

get_global("REQUEST_URI")

char *get_global(char *varname)
{
    zval **varvalue;

    if (
    zend_hash_find(Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_SERVER]), varname, strlen( varname ) + 1, (void **) &varvalue) == FAILURE)
    {
        php_error_docref(NULL TSRMLS_CC, E_NOTICE, "Undefined variable: %s", varname);
        return FAILURE;
    }

if (varvalue != NULL)
    {
    convert_to_string(*varvalue);
    return Z_STRVAL_PP(varvalue);
    }
else
    return "null";
}