PHP command line output buffer outputs regardless of buffer settings

I have some classes I am writing开发者_JS百科 unit tests for which have echoes in them. I want to suppress this output and thought ob_start() and ob_clean() would suffice, but they aren't having an effect.

public function testSomething (){
    ob_start();
    $class = new MyClass();
    $class->method();
    ob_clean();
}

I've also tried variations such as ob_start(false, 0, true); and ob_end_clean() to no avail.

What am I missing?

you may want something like this

<?php
public function testSomething (){
    ob_start();
    ob_implicit_flush(false); // turn off implicit flush

// Make your output below
    $class = new MyClass();
    $class->method();
// End of output

// store output into variable:
    $output = ob_get_contents();
}
?>

Do you have implicit_flush set to true in your PHP ini? This can cause the behaviour you are seeing as it tells PHP to tell the output layer to flush itself automatically after every output block. This is equivalent to calling the PHP function flush() after each and every call to print() or echo() and each and every HTML block.

The following solves this problem for me. Without calling ob_end_clean(), the contents of the buffer remain until the script's end, where it is flushed.

ob_implicit_flush(false);
ob_start();    
/*
  ...
  ... do something that pushes countent to the output buffer
  ...
*/    
$rendered = ob_get_contents();
ob_end_clean(); // Needed to clear the buffer