When single-stepping through PHP code during debugging (e.g. in Netbeans) I want to see PHP output in my browser immediately. This can be achieved (at least when using PHP7.2 and Firefox) by including the following at the start of the PHP code:
ob_implicit_flush ();
while (@ob_end_flush());
This ensures that things like
echo "foo\n";
immediately result in 'foo' being displayed in the web browser rather than when the output buffer is due for a flush or the PHP code exits upon completion or error.
But is there a way to achieve this by editing php.ini so I don't have to include it in every bit of PHP code to be debugged? (I understand this will result in a performance penalty, but this is for development and debugging purposes only.)
Flushing the output buffer is an implicit action that the developer must make, so isn't something that can be toggled on or off in the php.ini.
However, PHP does have a feature called ticks, which allows the developer to register a callback function to be called every X lines of code that are executed.
See register_tick_function, where you can define your own callback function to perform the flush, and have it run in between every statement in your program. This will obviously kill performance, and there is probably a better way of achieving what you're trying to do.
Example:
declare(ticks=1);
function autoFlushBuffer() {
ob_implicit_flush ();
while (@ob_end_flush());
}
register_tick_function("autoFlushBuffer", true);
// The following lines will appear in your web browser one by one:
echo "one";
sleep(1);
echo "two";
sleep(1);
echo "three";
sleep(1);