PHP in a Nutshell

Getting Started

There are two ways to start buffering output: through a php.ini setting to enable output buffering for all scripts, or by using a function call on a script-by-script basis. The latter is preferred, as it makes your code more portable and also gives you greater flexibility in how you use output buffering.

To create a new output buffer and start writing to it, call ob_start() . There are two ways to end a buffer: ob_end_flush() and ob_end_clean() . The former ends the buffer and sends all data to output, and the latter ends the buffer without sending it to output. Every piece of text written while an output buffer is open is placed into that buffer, as opposed to being sent to output. For example:

    ob_start();
    print "Hello First!\n";
    ob_end_flush();

    ob_start();
    print "Hello Second!\n";
    ob_end_clean();

    ob_start();
    print "Hello Third!\n";

That script will output "Hello First" because the first text is placed into a buffer and then flushed with ob_end_flush(). The "Hello Second" will not be printed out, though, because it is placed into a buffer that is cleaned using ob_end_clean() and not sent to output. Finally, the script will print out "Hello Third" because PHP automatically flushes open output buffers when it reaches the end of a script.