Delete a dynamic String value from path

@Naimish and @ Prasad. Thank you so much for both contribution and for helping me to increase my learning skills, this is how I use it:

private void button2_Click(object sender, EventArgs e)
		{
			try
			{
				if (string.IsNullOrEmpty(FromFile))
				{
					lblStatus.Text = "Missing CSV Information";
					MessageBox.Show("Please select a CSV file first.");
					return;
				}

				if (string.IsNullOrEmpty(ToFile))
				{
					lblStatus.Text = "Missing Save Information";
					MessageBox.Show("Please enter save information.");
					return;
				}
				else if (File.Exists(ToFile))
				{
					File.Delete(ToFile);
				}

				btnProcess.Enabled = false;
				lblStatus.Text = "Processing...";
				//TIF = 2, PDF= 16 column 6
				var lines = File.ReadAllLines(FromFile).Skip(1);
				string docId = "";
				string[] oldLine = null;

				string pattern = @".\\[^_]*_[^_]*_\d{8}_\d{8}_\d{4}\\";
				var sb = new StringBuilder();

				foreach (var line in lines)
				{
					var newLine = Regex.Replace(line, pattern, "").Replace("\"", "").Split(',');

					// Replace file extension in column 6 with numeric value
					if (newLine.Length > 5)
					{
						if (newLine[5].Equals("tif", StringComparison.OrdinalIgnoreCase))
						{
							newLine[5] = "2";
						}
						else if (newLine[5].Equals("pdf", StringComparison.OrdinalIgnoreCase))
						{
							newLine[5] = "16";
						}
					}

					if (docId != newLine[0])
					{
						docId = newLine[0];
						oldLine = newLine;
					}
					else
					{
						for (int i = COPY_FROM - 1; i < newLine.Length; i++)
							newLine[i] = oldLine[i];
					}

					sb.AppendLine(string.Join("|", newLine));
				}

				File.WriteAllText(ToFile, sb.ToString());

				//btnProcess.Enabled = true;
				//lblStatus.Text = "Completed";
			}
			catch (FileNotFoundException ex)
			{
				MessageBox.Show($"File not found: {ex.Message}");
			}
			catch (IOException ex)
			{
				MessageBox.Show($"IO error: {ex.Message}");
			}

Sure, I can help you with that.

Firstly, the regular expression you’re using seems to be incorrect. If you want to match the dynamic string in the path and replace it, you can use the following pattern:

string pattern = @"\\.\\[^_]*_[^_]*_[^_]*_[^_]*_\d{4}\\";

This pattern will match any string that starts with .\, followed by any characters until it encounters an underscore _, and repeats this four times, and finally matches four digits \d{4} and a backslash \\.

Secondly, for replacing ‘tif’ with ‘2’ and ‘pdf’ with ‘16’ in the third column, you can add the following code inside your foreach loop:

if (newLine[2].ToLower() == "tif") newLine[2] = "2";
else if (newLine[2].ToLower() == "pdf") newLine[2] = "16";

Here’s how your updated code would look like:

private void button2_Click(object sender, EventArgs e)
{
	try
	{
		if (string.IsNullOrEmpty(FromFile))
		{
			lblStatus.Text = "Missing CSV Information";
			MessageBox.Show("Please select a CSV file first.");
			return;
		}

		if (string.IsNullOrEmpty(ToFile))
		{
			lblStatus.Text = "Missing Save Information";
			MessageBox.Show("Please enter save information.");
			return;
		}
		else if (File.Exists(ToFile))
		{
			File.Delete(ToFile);
		}

		btnProcess.Enabled = false;
		lblStatus.Text = "Processing...";
		//TIF = 2, PDF= 16 column 6
		var lines = File.ReadAllLines(FromFile).Skip(1);
		string docId = "";
		string[] oldLine = null;

		string pattern = @"\\.\\[^_]*_[^_]*_[^_]*_[^_]*_\d{4}\\";
		var sb = new StringBuilder();

		foreach (var line in lines)
		{
			var newLine = Regex.Replace(line, pattern, "").Replace("\"", "").Split(',');

			if (newLine[2].ToLower() == "tif") newLine[2] = "2";
			else if (newLine[2].ToLower() == "pdf") newLine[2] = "16";

			if (docId != newLine[0])
			{
				docId = newLine[0];
				oldLine = newLine;
			}
			else
			{
				for (int i = COPY_FROM - 1; i < newLine.Length; i++)
					newLine[i] = oldLine[i];
			}

			sb.AppendLine(string.Join("|", newLine));
		}

		File.WriteAllText(ToFile, sb.ToString());

		//btnProcess.Enabled = true;
		//lblStatus.Text = "Completed";
	}
	catch (Exception ex)
	{
		// Handle exception
	}
}

Thanks

please try with this

private void button2_Click(object sender, EventArgs e)
{
    try
    {
        if (string.IsNullOrEmpty(FromFile))
        {
            lblStatus.Text = "Missing CSV Information";
            MessageBox.Show("Please select a CSV file first.");
            return;
        }

        if (string.IsNullOrEmpty(ToFile))
        {
            lblStatus.Text = "Missing Save Information";
            MessageBox.Show("Please enter save information.");
            return;
        }
        else if (File.Exists(ToFile))
        {
            File.Delete(ToFile);
        }

        btnProcess.Enabled = false;
        lblStatus.Text = "Processing...";
        
        // TIF = 2, PDF = 16 column 6
        var lines = File.ReadAllLines(FromFile).Skip(1);
        string docId = "";
        string[] oldLine = null;

        // Regular expression pattern to remove the dynamic part of the path
        string pattern = @"_\d{4}\\";

        var sb = new StringBuilder();

        foreach (var line in lines)
        {
            // Remove the dynamic part of the path
            var newLine = Regex.Replace(line, pattern, "").Replace("\"", "").Split(',');

            // Replace file extension in column 6 with numeric value
            if (newLine.Length > 5)
            {
                if (newLine[5].Equals("tif", StringComparison.OrdinalIgnoreCase))
                {
                    newLine[5] = "2";
                }
                else if (newLine[5].Equals("pdf", StringComparison.OrdinalIgnoreCase))
                {
                    newLine[5] = "16";
                }
            }

            if (docId != newLine[0])
            {
                docId = newLine[0];
                oldLine = newLine;
            }
            else
            {
                for (int i = COPY_FROM - 1; i < newLine.Length; i++)
                    newLine[i] = oldLine[i];
            }

            sb.AppendLine(string.Join("|", newLine));
        }

        File.WriteAllText(ToFile, sb.ToString());

        //btnProcess.Enabled = true;
        //lblStatus.Text = "Completed";
    }
    catch (Exception ex)
    {
        lblStatus.Text = "Error: " + ex.Message;
        MessageBox.Show("An error occurred: " + ex.Message);
    }
}

1. Regex Pattern: _\d{4}\\ matches the underscore, followed by exactly four digits, and the backslash.
2. Replacing File Extensions: In the loop, check if the sixth column (index 5) is tif or pdf and replace it with 2 or 16 respectively.

This should fulfill your requirements of removing the dynamic part of the path and replacing the file extensions with their corresponding numeric values. Adjust COPY_FROM as per your actual column index for copying values from the old line to the new line.