How can i parse specific string from text file reading all lines?

Question

In each line i want to parse the string after the tag

I know it's html but i copied this part of the html to text file. For example the first two lines in the text file are like this:

<li>602 — <a href="/w/index.php?title=Text602&amp;action=edit&amp;redlink=1" class="new" title="Text602 (page does not exist)">Text602</a> document</li>
<li>ABW — <a href="/wiki/AbiWord" title="AbiWord">AbiWord</a> Document</li>

I want to parse the 602 from the first line and the ABW from the second line. What i tried to do is:

private void ParseFilesTypes()
        {
            string[] lines = File.ReadAllLines(@"E:\New folder (44)\New Text Document.txt");
            foreach (string str in lines)
            {
                int r = str.IndexOf("<li>");
                if (r >= 0)
                {
                    int i = str.IndexOf(" -", r + 1);
                    if (i >= 0)
                    {

                        int c = str.IndexOf(" -", i + 1);
                        if (c >= 0)
                        {
                            i++;
                            MessageBox.Show(str.Substring(i, c - i));
                        }
                    }
                }
            }
        }

But c is all the time -1

Upvotes: 1

Views: 79

Answer 1

Actually, your problem is that you're reading the file with the incorrect encoding. You have a special character in your file — and not -. So you need to correct this character in your code and read the file in the correct encoding. If you debug your string read with wrong encoding, you'll see a black diamond instead of —.

Also, you need to remove the space before — or replace i + 1 with i;

private static void ParseFilesTypes()
{
    string sampleFilePath = @"log.txt";
    string[] lines = File.ReadAllLines(@"log.txt", Encoding.GetEncoding("windows-1252"));
    foreach (string str in lines)
    {
        int r = str.IndexOf("<li>");
        if (r >= 0)
        {
            int i = str.IndexOf(" —", r + 1);
            if (i >= 0)
            {

                int c = str.IndexOf(" —", i);
                if (c >= 0)
                {
                    i++;
                    int startIndex = r + "<li>".Length;
                    int length = i - startIndex - 1;
                    string result = str.Substring(r + "<li>".Length, length);
                    MessageBox.Show(result);
                }
            }
        }
    }
}

Answer 2

I think it is a case when regex would be useful (unless there will be no li attributes):

var regex = new Regex("^<li>(.+) —");
foreach (string str in lines)
{
     var m = regex.Match(str);
     if (m.Success)
        MessageBox.Show(m.Groups[1].Value);
}