使用Javascript从一个文本区域逐行分析substr（0,6）到另一个文本区域

Question

Originally this started with me trying to parse a text file upload through an input field but everything I researched came up with HTML5 and I don't want to use that. So then I switched to just pasting text into a textarea(input) and having Javascript parse it grabbing the first 16 characters to place in textarea (output1) and grabbing the first 6 characters to place in textarea (output2). When I do this it only parses the first line. I am sure this can be done with a loop but I haven't quite mastered loops yet.

The data I paste in would be like:

A2C6F8-008CFF294
C4F2D1-008CAB312

So output1 should have the first six, and output2 should have the whole line in these examples.

Here is the code I have. Not sure what the next steps are.

function trimit() {
    var str = "";
    str = document.getElementById("input").value;
    var six = str.substr(0,6);
    var sixteen = str.substr(0,16);
    document.getElementById("output1").value = six;
    document.getElementById("output2").value = sixteen; }

<table>
        <tr>
          <td><div align="center"><textarea name="input" cols="25" rows="10" id="input" onchange="trimit();"></textarea></div></td>
          <td><div align="center"><textarea name="output1" cols="7" rows="10" id="output1"></textarea></div></td>
          <td><div align="center"><textarea name="output2" cols="20" rows="10" id="output2"></textarea></div></td>
        </tr>
</table>

I realize that there is redundancy in my javascript. I tend to do that when I am troubleshooting to make sure I don't miss something. After I solve this I am going to take the same input, substr 6 characters and then change all of the line breaks into commas so I can submit it to a database query.

This is my first time posting here so I apologize if I missed something you wanted. I have read thousands of SO questions and should know what to put.

Update: I was going to add a picture but apparently I am not worthy yet so here is an ASCII model.

+---------INPUT---------+   +-----OUTPUT1-----+   +-------OUTPUT2-------+
| A2C6F8-008CFF294      |   | A2C6F8          |   | A2C6F8-008CFF294    |
| C4F2D1-008CAB312      |   | C4F2D1          |   | C4F2D1-008CAB312    |
|                       |-->|                 |-->|                     |
|                       |   |                 |   |                     |
|                       |   |                 |   |                     |
+-----------------------+   +-----------------+   +---------------------+

Answer 1

If I'm understanding correctly, you want the first 16 characters of each input line to show up in one of your output boxes and just the first 6 characters of the same to show up in the other.

You can use regular expressions and get what you want. So, first as an illustration:

"A2C6F8-008CFF294\nC4F2D1-008CAB312".match(/^....../mg) // match first 6 of each line
      ==> ["A2C6F8", "C4F2D1"]
"A2C6F8-008CFF294\nC4F2D1-008CAB312".match(/^................/mg) // match first 16 of each line
      ==> ["A2C6F8-008CFF294", "C4F2D1-008CAB312"]

So your function would be:

function trimit() {
    var str = "";
    str = document.getElementById("input").value;  
    var sixes = str.match(/^....../mg);
    var sixteens = str.match(/^................/mg);  
    document.getElementById("output1").value = sixes.join('\n');
    document.getElementById("output2").value = sixteen.join('\n'); }