[js] clipboard 읽기&쓰기

function copyToClipboard(val) {
  let t = document.createElement('textarea')
  document.body.appendChild(t)
  t.value = val
  t.select()
  document.execCommand('copy')
  document.body.removeChild(t)
}

<textarea id="output"></textarea>
<button id="paste">Paste</button>

function paste() {
  var pasteText = document.querySelector("#output");
  pasteText.focus();
  document.execCommand("paste");
  console.log(pasteText.textContent);
}

document.querySelector("#paste").addEventListener("click", paste);

navigator.clipboard.readText()
  .then(text => {
    console.log('Pasted content: ', text);
  })
  .catch(err => {
    console.error('Failed to read clipboard contents: ', err);
  });