You can also print execution information, such as the current file being executed. The name of the function currently being executed can be retrieved using the function get_active_function_name(). This function returns a pointer to the function name and doesn't accept any arguments. To retrieve the name of the file currently being executed, use zend_get_executed_filename(). This function accesses the executor globals, which are passed to it using the TSRMLS_C macro. The executor globals are automatically available to every function that's called directly by Zend (they're part of the INTERNAL_FUNCTION_PARAMETERS described earlier in this chapter). If you want to access the executor globals in another function that doesn't have them available automatically, call the macro TSRMLS_FETCH() once in that function; this will introduce them to your local scope.
Finally, the line number currently being executed can be retrieved using the function zend_get_executed_lineno(). This function also requires the executor globals as arguments. For examples of these functions, see Example 36-2.