Constantly read local file with JS?

Constantly read local file with JS?

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Constantly read local file with JS?
Tag : javascript , By : user160048
Date : November 28 2020, 04:01 AM

To fix this issue You can enable XmlHttpRequest for local files by starting Chrome with it's security features disabled. This is not an ideal solution but it is the only way to automatically do what you want without running some kind of server. Using Node to watch the file for changes and pushing the data over a WebSocket to the browser would be the proper way to handle this.
Alternatively you could use the FileReader API to open this local file but you need to select it manually through an element first.
function readInputFile(event) {
  let file = event.target.files[0];

  if (!file) {
  let reader = new FileReader();
  reader.addEventListener('load', event => {
    let content = event.target.result;

document.getElementById('datafile').addEventListener('change', readInputFile, false);
<input type="file" id="datafile">

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PHP: How to read a file live that is constantly being written to

Tag : php , By : Webtoad
Date : March 29 2020, 07:55 AM
With these it helps I want to read a log file that is constantly being written to. It resides on the same server as the application. The catch is the file gets written to every few seconds, and I basically want to tail the file on the application in real-time. , You need to loop with sleep:
$lastpos = 0;
while (true) {
    usleep(300000); //0.3 s
    clearstatcache(false, $file);
    $len = filesize($file);
    if ($len < $lastpos) {
        //file deleted or reset
        $lastpos = $len;
    elseif ($len > $lastpos) {
        $f = fopen($file, "rb");
        if ($f === false)
        fseek($f, $lastpos);
        while (!feof($f)) {
            $buffer = fread($f, 4096);
            echo $buffer;
        $lastpos = ftell($f);

Constantly read a file for a particular string?

Tag : chash , By : Ambarish Singh
Date : March 29 2020, 07:55 AM
it fixes the issue In the assembly, I used a timer to periodically check the .txt file status, something like this:
System.Timers.Timer _logFileCheckTimer;
    public FijiLauncherControl()

    {        // timer set up
                    _logFileCheckTimer = new System.Timers.Timer(250);  
                    _logFileCheckTimer.Enabled = true;
                    _logFileCheckTimer.Elapsed += new System.Timers.ElapsedEventHandler(_logFileCheckTimer_Elapsed);
                   _logFileCheckTimer.Start();  // start the timer


     void _logFileCheckTimer_Elapsed(object sender, EventArgs e)
            if (_processOn && IsLogOn)
                    _processFinished = CheckStatuts();  // checking file status

                    if (_processFinished) // fire event if checking status returns true
                        _processOn = false;
                catch (Exception ex)

   protected virtual void OnIjmFinished(EventArgs e)
      if (IjmFinished != null)   // trigger event
                IjmFinished(this, e);          
private FijiLauncherControl _fl; // the object of your assembly

  _fl.IjmFinished += new IjmFinishedEventHandler(_fl_IjmFinished); // event from the assembly should trigger an event handler

   void _fl_IjmFinished(object sender, EventArgs e)   // event handler
            _vm.IjmFinished = true;   // a boolean var in viewmodel in main app set to be true once the event from the assembly is triggered

            //throw new NotImplementedException();

PHP: How to constantly read a file

Tag : php , By : micate
Date : March 29 2020, 07:55 AM
I hope this helps you . If your file have only one string, and you need to read it on change, use this code:
$file = '/path/to/test.txt';
$last_modify_time = 0;
while (true) {
    sleep(1); // 1 s
    clearstatcache(true, $file);
    $curr_modify_time = filemtime($file);
    if ($last_modify_time < $curr_modify_time) {
        echo file_get_contents($file);

    $last_modify_time = $curr_modify_time;
<!DOCTYPE html>
    <meta charset="UTF-8">
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"
    <div id="file_content"></div>
        var time = 0;
        setInterval(function() {
                type: "POST",
                data: {time : time},
                url: "fileupdate.php",
                success: function (data) {
                    var result = $.parseJSON(data)
                    if (result.content) {
                        $('#file_content').append('<br>' + result.content);
                    time = result.time;
        }, 1000);
$file = 'test.txt';
$result = array();
clearstatcache(true, $file);

$data['time']    = filemtime($file);
$data['content'] = $_POST['time'] < $data['time']
    ? file_get_contents($file)
    : false;

echo json_encode($data);

How do you read a local file on your PC and update it constantly in javascript?

Tag : javascript , By : Terrence Poon
Date : March 29 2020, 07:55 AM
wish help you to fix your issue Doing some more research, it's security reasons as to why you can't access a file from the local computer.
So, in lieu of all that, I made some code that will constantly load the selected file so you can see whenever it changes:
<title>Import Data</title>
var input;

    var openFile = function() {

        var reader = new FileReader(event);
        reader.onload = function() {
            var text = reader.result;
            var node = document.getElementById('output');
            node.innerText = text;

<input type='file' accept='text/plain' onchange='input = event.target; openFile(event);'><br>
<div id='output'>

How do I read a file which is constantly updating?

Tag : perl , By : Praetoriansentry
Date : March 29 2020, 07:55 AM
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