Control output being sent while it's being processed

Question

I've implemented a file optimization script which takes about 30 seconds or more. There's a loop in which I added echos to track what's being processed.

However, most of the time, no output is being sent, until the end of the process.

How can I control this in order to send the echos in an iteration just as they're being finished?

EDIT:

This is the implied code, with the output buffer functions:

    set_time_limit(60);
    ini_set("memory_limit", "256M");

    $documents = $this->documents_model->get($date1, $date2);

    ob_start();

    echo '-- Start ' . "<br>\n";

    ob_end_flush();
    flush();

    foreach ($documents as $document) {

        ob_start();

        echo '-- Processing document ' . $document->id . "<br>\n";

        $file = $document->get_file_name();
        if (! $file || ! file_exists(DOCUMENT_ROOT . 'documents/' . $file)) {

            echo '---- Document ' . $document->id . " has no PDF file yet or it was deleted<br>\n";

            $path = $this->documents_model->generatePDF($document);
            echo '------ file generated: ' . $path;
        }

        ob_end_flush();
        flush();
    }

    echo '-- End ' . "<br>\n";

Checkout the `ob_buffer` in PHP. You can force it to flush output when you want instead of waiting for the script to do it. — The Unknown Dev, Apr 01 '16 at 13:19

score 1 · Answer 1 · edited May 23 '17 at 12:24

1

The reason why you will get the output after the processing finishes, is php's output buffer and eventually your webserver's buffer.

You will have to flush these buffers with the invokation of ob_flush() and flush() after every few echo statements.

For more technical information see PHP buffer ob_flush() vs. flush()

edited May 23 '17 at 12:24

Community

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answered Apr 01 '16 at 12:24

l-x

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It's not working either with ob_flush() or flush(), or their combination. All the output is displayed at the end of the processing. – luis.ap.uyen Apr 01 '16 at 13:20

Control output being sent while it's being processed

1 Answers1