CODEWITHSUNDEEP
phpjavascript
Jarek
Jarek

Reputation: 145

Updating web page with txt file contents using PHP

I am using PHP to read in a .txt file, and parsing the data to a webpage. The .txt file is a local log file that displays my server's status, and I can currently read out the last line and push it out to my site.

However, when my server's status changes, the .txt file becomes updated locally, but the new value never shows up on the site.

I am using HTML5/Javascript for displaying the contents, and PHP for reading the file and parsing/cleaning up the input. The code segment I am attaching, which shows the PHP file reading functions I am using, runs every 10 seconds. After this segment is run, the display (I am using an HTML5 canvas) is refreshed, but the data stays constant. The display only updates if I manually refresh the page.

Is it possible that to poll this txt file every 10 seconds or so, and push the last line out into a variable I can call?

function getCurrentStatus() {
    <?php           
        clearstatcache();

        $myFile = "C:\available.log";

        $fh = fopen($myFile, 'r');
        $theData = fread($fh, filesize($myFile));
        fclose($fh);

        $statusList = explode("\n", $theData);
        $statusListLength = count($statusList) - 2;
        $currentStatus = explode(" ", $statusList[$statusListLength]);
        $previousStatus = explode(" ", $statusList[$statusListLength - 1]);

        $myFile = "C:\std_server0.out";

        $fh = fopen($myFile, 'r');
        $theData = fread($fh, filesize($myFile));
        fclose($fh);

        $garbageCollector = array_map('trim',explode("\n", $theData));
        $garbageCollectorLength = count($garbageCollector);
    ?>
    currentStatus = ["Latest Status:", "<?php echo $currentStatus[0]; ?>", "First Started:", "<?php echo $currentStatus[1]; ?>", "<?php echo $currentStatus[2]; ?>", "Last Checked:", "<?php echo $currentStatus[4]; ?>", "<?php echo $currentStatus[5]; ?>"];      

    latestGC = "<?php echo $garbageCollector[$garbageCollectorLength - 2] ?>"
}

Upvotes: 2

Views: 1301

Answers (3)

user2490528
user2490528

Reputation: 1

I had a similar problem and found that it was a problem with browser caching. You can check this by opening developer tools in Chrome (Windows / Linux = Ctrl + Shift + I, Mac = Cmd + Opt + I) and disabling caching there.

If this solves the problem, then you need to find a workaround. You can add a unique dummy query string to each page to fool the browser into thinking that it was a unique page. In my case, I created a timestamp using time() and appended it to the page url.

Upvotes: 0

jprofitt
jprofitt

Reputation: 10964

The reason this isn't working is because JavaScript is executed in the client's browser, where the PHP is executed on the server. So in the initial load, you're getting what you'd expect because as the page was being created, PHP got the contents of that file. After that, however, PHP is gone and out of the picture.

You'll probably need to look into using AJAX to periodically refresh the contents.

Upvotes: 2

Ravi Bhatt
Ravi Bhatt

Reputation: 3163

Polling something is not a good idea. What you need is a server push about new data or changed data. Have a look at this http://www.zeitoun.net/articles/comet_and_php/start

Hope this helps.

Upvotes: 0

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