Question

I make an AJAX POST request to a PHP script on my server. That script in turn makes a GET request to a php script on an external server to check the contents of a text file. However, it takes a very long time to come back with a result. Why is the case?

AJAX Post Request to Script on my server

session_start();
$fileName = $_POST['textFile'];
$result = file_get_contents($_SESSION['serverURL']."fileReader.php?textFile=$fileName");
echo $result;

GET Request to a script on different server

$fileName = $_GET['textFile'];

if (file_exists('text/'.$fileName.'.txt')) {

    $lines = file('text/'.$fileName.'.txt');

    echo $lines[sizeof($lines)-1];

}
else{
    echo 0;
}

These are very simple scripts and its only checking a very small text file, so why does it take so long?

I am making other AJAX request on my site but these surely can’t be causing a problem. Having said this, the returned value of that text file always co-incides with the completion of another AJAX request which initiates a script that takes a while to complete on my server, but how would these effect each other?! They shouldn’t right?

Answer 1

You don’t have to take the route over HTTP to get the last line of a file. Why don’t you stay inside the file system and use a function like that to retrieve the last line:

function fileGetLine($filename, $line) {
    if (!is_file($filename) || !is_readable($filename)) {
        // invalid file name or not readable
        return false;
    }
    if (!is_int($line)) {
        // invalid line number
        return false;
    }
    $lines = file($filename);
    $lineCount = count($lines);
    if ($line < 0) {
        // negative line number, count from end
        $line = $lineCount + $line;
    }
    if ($line < 0 || $line >= $lineCount) {
        // line number out of bounds
        return false;
    }
    return $lines[$line];
}

session_start();
echo fileGetLine('text/'.basename($_POST['textFile']).'.txt', -1);