Reputation: 1636

C# - Read/Copy/Replace Lines In Text

I have a text file that I am opening up and it is in a similar format to this:

  10 SOME TEXT
  20 T A40
  B B5, C45, D48
  30 B E25
  40 B F17, G18
  60 T H20, I23,
  B J6, K7, L8, M9, N10, O11, P12,
  Q31, R32, S33, T34, U35, V36,
  W37, X38, Y39
  100 T Z65
  360 B A1, B4, C5, D6, E7, F10
  2000 T SOME TEXT
  423 TEXT

With this text I need to be able to read it and replace values accordingly. If a ReadLine begins with a number (ie, 10, 20, 30, 40, 60, 100, 360, 2000, 423) I need to to check if there is a T, B, or text after it. The only case that I need to change/reformat the lines when they come in and output them differently.

Example: 10 is fine except for I would like to add zeros in front of every number to make them 4 digits long (ie, 10 turns to 0010, 360 turns to 0360, 2000 stays the same). When the string "B B5, C45, D48" is read (this is the third line in the text) I need to change it to say "20A B5, C45, D48". I need to grab the number above the "B" and concat it to the "B" and replace the "B" with an "A". If instead of a "B" there is a "T" I simply need to remove the "T". Also, if a line does not start with a number or a "B" (ie, Q31 or W37) I need to concat that line with the previous line.

So after the changes take place it should look like this:

  0010 SOME TEXT
  0020 A40
  0020A B5, C45, D48
  0030A E25
  0040A F17, G18
  0060 H20, I23,
  0060A J6, K7, L8, M9, N10, O11, P12, Q31, R32, S33, T34, U35, V36, W37, X38, Y39
  0100 Z65
  0360A A1, B4, C5, D6, E7, F10
  2000 SOME TEXT
  0423 TEXT

I am currently trying to use Regex to do this but I have been told that there is an easier way to do this and I am not sure how. So far I have been able to add the zeros in front of the numbers. Also, my code is adding an "A" to the end of everything as well as keeping the original number on the next line and I am not grabbing the lines that begin with anything but a digit.

This is what my current output is turning out to look like:

I am obviously doing something wrong using Regex.

Here is my current code:

    private void openRefsButton_Click(object sender, EventArgs e)
    {
        // Initialize the OpenFileDialog to specify the .txt extension as well as
        // its intial directory for the file.
        openRefs.DefaultExt = "*.txt";
        openRefs.Filter = ".txt Files|*.txt";
        openRefs.InitialDirectory = "C:\\";
        openRefs.RestoreDirectory = true;

        try
        {
            // Open the contents of the file into the originalTextRichTextBox.
            if (openRefs.ShowDialog() == DialogResult.OK && openRefs.FileName.Length > 0)
                refsTextRichTextBox.LoadFile(openRefs.FileName, RichTextBoxStreamType.PlainText);

            // Throws a FileNotFoundException otherwise.
            else
                throw new FileNotFoundException();

            StreamReader refsInput = File.OpenText(openRefs.FileName);

            string regExpression = @"^[\d]+";
            string findNewBottomRegex = @"^B\s";

            StringBuilder buildNumberText = new StringBuilder();
            StringBuilder formatMatchText = new StringBuilder();

            foreach (string allLines in File.ReadAllLines(openRefs.FileName))
            {
                Match newBottomMatch = Regex.Match(allLines, findNewBottomRegex);
                Match numberStartMatch = Regex.Match(allLines, regExpression);
                int counter = 0;

                if (counter < numberStartMatch.Length)
                {
                    if (numberStartMatch.Value.Length == 2)
                    {
                        if (refsTextRichTextBox.Text.Contains(newBottomMatch.ToString()))
                        {
                            finalTextRichTextBox.AppendText("00" + numberStartMatch + "A\n");
                        }

                        finalTextRichTextBox.AppendText("00" + numberStartMatch + "\n");
                    }

                    else if (numberStartMatch.Value.Length == 3)
                    {
                        if (refsTextRichTextBox.Text.Contains(newBottomMatch.ToString()))
                        {
                            finalTextRichTextBox.AppendText("0" + numberStartMatch + "A\n");
                        }

                        finalTextRichTextBox.AppendText("0" + numberStartMatch + "\n");
                    }

                    else
                    {
                        if (refsTextRichTextBox.Text.Contains(newBottomMatch.ToString()))
                        {
                            finalTextRichTextBox.AppendText(numberStartMatch + "A\n");
                        }

                        finalTextRichTextBox.AppendText(numberStartMatch + "\n");
                    }
                    counter++;
                }
            }
        }

        // Catches an exception if the file was not opened.
        catch (Exception)
        {
            MessageBox.Show("There was not a specified file path.", "Path Not Found Error",
                            MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
    }
}

}

QUESTION(S):

What is a better way to go about doing this task?
Are there any recommendations on changing my code to be more efficient and cleaner?
How do I properly split each line into number, T/B, A40 when every line is not the same?
After the lines are properly split, how do I replace copy the line before if the current line begins with a "B"?
- If the line begins with "Q31" or similar, how do I add that current line to the end of the previous one?
Once this happens, is there a way to concat everything to create the speficied format above?

WORK FLOW @jaywayco

Open Text File
Read file line by line
- Save each line in a list of strings
Split each string by ' '
Find each line that starts with a digit
- Replace that digit to make it 4 digits in length
- Check the following text after the digit to see if it is a "B ", "T ", or "SOME TEXT"
  - if "B " copy the line above
    - Add an "A" to the end of the digit
  - if "T " remove the "T "
  - if "SOME TEXT" do nothing
Find each line that starts with a "B "
- Copy the digits on the line above and concat to the front of the "B "
  - Follow step 4.b.i
Find each line that starts with (or similar to) "Q31"
- Concat this line to the end of the previous line
...?

Upvotes: 3

Answers (4)

Dave Ziegler

Reputation: 1745

Here's a really lame, procedural solution:

using System.IO;
using System.Collections.Generic;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            var list = new List<string>();

            using (var reader = File.OpenText(@"c:\input.txt"))
            {
                while (true)
                {
                    var line = reader.ReadLine();
                    if (string.IsNullOrEmpty(line)) break;
                    list.Add(line);
                }
            }

            list = HandleRemoveTRequirement(list);
            list = HandleFourDigitRequirement(list);
            list = HandleConcatRequirement(list);
            list = HandleStartsWithBRequirement(list);
            list = HandleSecondElementIsBRequirement(list);

            using (var output = new StreamWriter(@"c:\output.txt"))
            {
                foreach (var line in list)
                {
                    output.WriteLine(line);
                }
            }
        }

        static List<string> HandleSecondElementIsBRequirement(List<string> list)
        {
            var result = new List<string>();

            foreach (var line in list)
            {
                var parts = line.Split(' ');

                if (parts[1].Equals("B"))
                {
                    parts[0] += "A";
                    parts[1] = string.Empty;
                    result.Add(string.Join(" ", parts).Replace("  ", " "));
                }
                else
                {
                    result.Add(line);
                }
            }

            return result;
        }

        static List<string> HandleStartsWithBRequirement(List<string> list)
        {
            var result = new List<string>();
            var i = 0;

            foreach (var line in list)
            {
                var parts = line.Split(' ');

                if (parts[0].Equals("B"))
                {
                    parts[0] = string.Empty;
                    result.Add(list[i - 1].Split(' ')[0] + "A" + string.Join(" ", parts));
                }
                else
                {
                    result.Add(line);
                }

                i++;
            }

            return result;
        }

        static List<string> HandleConcatRequirement(List<string> list)
        {
            var result = new List<string>();

            foreach (var line in list)
            {
                var parts = line.Split(' ');
                int test;
                if (int.TryParse(parts[0], out test) || parts[0].Equals("B"))
                {
                    result.Add(line);
                }
                else
                {
                    result[result.Count -1] += line;
                }
            }

            return result;
        }

        static List<string> HandleRemoveTRequirement(List<string> list)
        {
            var result = new List<string>();

            foreach (var line in list)
            {
                var parts = line.Split(' ');
                if (parts[1].Equals("T"))
                {
                    parts[1] = string.Empty;
                }
                result.Add(string.Join(" ", parts).Replace("  ", " "));
            }

            return result;
        }

        static List<string> HandleFourDigitRequirement(List<string> list)
        {
            var result = new List<string>();

            foreach (var line in list)
            {
                var parts = line.Split(' ');
                int test;
                if (int.TryParse(parts[0], out test))
                {
                    parts[0] = parts[0].PadLeft(4, '0');
                    result.Add(string.Join(" ", parts));
                }
                else
                {
                    result.Add(line);
                }
            }

            return result;
        }
    }
}

Upvotes: 2

Alex Peck

Reputation: 4711

The way I would go about this task is to write a set of unit tests based on your requirements, then make them pass one at a time (having one test per requirement).

As jaywayco suggested, I would read the file into an array of lines, then implement each of your rules as a line transformation method which can be tested in isolation. I would probably separate out the method which can select which transformation(s) to apply. Then loop over the lines and apply the transformations.

Upvotes: 1

Alex

Reputation: 2144

One way to possibly approach this is similiar to jaywayco's.

I'd start with placing each line split by spaces into it's own array. Place that array into an Array of arrays. From there you can consider your workflow. Your line array that is split by the spaces you can determine how to print it based off the first value, being a number or letter B etc... If it's a B, you know that it should start with array[i-1] first value, which would be the number etc. You'd have to think through the logic a bit, but I think you can understand where I am coming from. I'm not sure if this is the best approach or not, but I think this is the way I would tackle it. Good luck!

Edit: Here is some mock code...

var mainArray = new Array[textFile.Count];  
//obviously get the count of number of lines set that to the size of your array object.

for(int i=0; i < mainArray.Length; i++)
{
     var line = methodToGetLineFromTextFile[i];
     string[] lineArray = line.Split(' ');
     mainArray[i] = lineArray;
}

//Once you have everything loaded into your arrays, apply your workflow logic.

Hope this helps!

Upvotes: 1

jaywayco

Reputation: 6296

These are pretty complicated requirements and I would be tempted to implement this as a workflow. This way you can separate out each of the logical steps and this will increase maintainability.

I would be tempted to represent the text file as an array of string arrays or even a data table. Then you can write general functions that concatenate/transform specific values

Upvotes: 1

C# - Read/Copy/Replace Lines In Text

Answers (4)

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