espltd,
<!DOCTYPE HTML>
<html>
<head>
<title>example</title>
<meta charset="utf-8">
</head>
<body>
<textarea style="width: 300px; height: 150px;">text1
text2
text3
text4
</textarea><br/>
<input type="text" class="out">
<input type="text" class="out">
<input type="text" class="out">
<input type="text" class="out">
<script>
var textarea = document.querySelector('textarea'),
out = document.querySelectorAll('input.out');
textarea.oninput = function ()
{
var myList = textarea.value.split(/[\r\n]+/);
for (var i = 0, ln = myList.length; i < ln; ++i)
out[i] && (out[i].value =myList[i]);
}
</script>
</body>
</html>