(PECL runkit >= 0.7.0)
Specify a function to capture and/or process output from a runkit sandbox
mixed runkit_sandbox_output_handler ( object $sandbox [, mixed $callback ] )
Ordinarily, anything output (such as with echo or print) will be output as though it were printed from the parent's scope. Using runkit_sandbox_output_handler() however, output generated by the sandbox (including errors), can be captured by a functi