How To watch a file write in PHP?

Question

I want to make movement such as the tail command with PHP, but how may watch append to the file?

Answer 1

Below is what I adapted from above. Call it periodically with an ajax call and append to your 'holder' (textarea)... Hope this helps... thank you to all of you who contribute to stackoverflow and other such forums!

/* Used by the programming module to output debug.txt */
session_start();
$_SESSION['tailSize'] = filesize("./debugLog.txt");
if($_SESSION['tailPrevSize'] == '' || $_SESSION['tailPrevSize'] > $_SESSION['tailSize'])
{
      $_SESSION['tailPrevSize'] = $_SESSION['tailSize'];
}
$tailDiff = $_SESSION['tailSize'] - $_SESSION['tailPrevSize'];
$_SESSION['tailPrevSize'] = $_SESSION['tailSize'];

/* Include your own security checks (valid user, etc) if required here */

if(!$valid_user) {
   echo "Invalid system mode for this page.";
}
$handle = popen("tail -c ".$tailDiff." ./debugLog.txt 2>&1", 'r');
while(!feof($handle)) {
    $buffer = fgets($handle);
    echo "$buffer";
    flush(); 
}
pclose($handle);