How to open a local disk file with JavaScript?

Question

I tried to open file with

window.open(\"file:///D:/Hello.txt\");

The browser does not allow opening a local file this way, probably for sec

Answer 1

Try

function readFile(file) {
  return new Promise((resolve, reject) => {
    let fr = new FileReader();
    fr.onload = x=> resolve(fr.result);
    fr.readAsText(file);
})}

but user need to take action to choose file

function readFile(file) {
  return new Promise((resolve, reject) => {
    let fr = new FileReader();
    fr.onload = x=> resolve(fr.result);
    fr.readAsText(file);
})}

async function read(input) {
  msg.innerText = await readFile(input.files[0]);
}

Content: