C# - Extracting satellite two line elements from a text file

Question

I'm very new to c# and programming in general so I apologise if this doesn't make sense... I need to be able to search a textbox or combobox to read a notepad file containing many satellite two line element codes. The text file is set out like this:

0 VANGUARD 1
1 00005U 58002B   14242.42781498  .00000028  00000-0  24556-4 0  2568
2 00005 034.2497 271.4959 1848458 183.2227 175.4750 10.84383299975339
0 TRANSIT 2A
1 00045U 60007A   14245.43855606  .00000265  00000-0  95096-4 0  2208
2 00045 066.6958 193.0879 0251338 053.7315 060.2264 14.33038972819563
0 EXPLORER 11
1 00107U 61013A   14245.36883128  .00001088  00000-0  12832-3 0  1217
2 00107 028.7916 229.2883 0562255 219.9933 302.0575 14.05099145667434

Etc.

I need to search the box for the only satellite's name (the name after the 0 in the 'first' row) and extract that name into another textbox, and to use in my code. Additionally, I need to seperately extract the 2 lines of code directly beneath the name selected in the box (also to use in the code).

I have written code to use these two line elements, but I'm not able to automatically put them in my code.

Thank you

Answer 1

You can use regular expressions for this task.

(I assume that the letters/numbers block after the name is also part of the name)

This code will do the following:

• capture the name of the satellite and the two lines into a Satellite object
• populate a ComboBox with the names of the satellite
• whenever you selected a satellite you can know which one it was
• a search box that searches for the first satellite beginning with the typed text

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        private readonly BindingList<Satellite> _satellites = new BindingList<Satellite>();
        private string _input = @"
0 VANGUARD 1
1 00005U 58002B   14242.42781498  .00000028  00000-0  24556-4 0  2568
2 00005 034.2497 271.4959 1848458 183.2227 175.4750 10.84383299975339
0 TRANSIT 2A
1 00045U 60007A   14245.43855606  .00000265  00000-0  95096-4 0  2208
2 00045 066.6958 193.0879 0251338 053.7315 060.2264 14.33038972819563
0 EXPLORER 11
1 00107U 61013A   14245.36883128  .00001088  00000-0  12832-3 0  1217
2 00107 028.7916 229.2883 0562255 219.9933 302.0575 14.05099145667434
";

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            var regexObj =
                new Regex(@"(?<=^\d+\s(?<name>[\w|\d|\s]+))\r\n(?<line1>(?<=^).*)\r\n(?<line2>(?<=^).*(?=\r))",
                    RegexOptions.Multiline);
            Match matchResult = regexObj.Match(_input);

            while (matchResult.Success)
            {
                string name = matchResult.Groups["name"].Value;
                string line1 = matchResult.Groups["line1"].Value;
                string line2 = matchResult.Groups["line2"].Value;


                var regexObj1 = new Regex(@"(?<=^[1|2].*)([\d\w.-]+)");
                Match matchResult1 = regexObj1.Match(line1);
                var numbers1 = new List<string>();
                while (matchResult1.Success)
                {
                    string s = matchResult1.Value;
                    numbers1.Add(s);
                    matchResult1 = matchResult1.NextMatch();
                }

                var regexObj2 = new Regex(@"(?<=^[1|2].*)([\d\w.-]+)");
                Match matchResult2 = regexObj2.Match(line2);
                var numbers2 = new List<string>();
                while (matchResult2.Success)
                {
                    string s = matchResult2.Value;
                    numbers2.Add(s);
                    matchResult2 = matchResult2.NextMatch();
                }

                _satellites.Add(new Satellite
                {
                    Name = name,
                    Line1 = line1,
                    Line2 = line2,
                    Numbers1 = numbers1,
                    Numbers2 = numbers2
                });


                matchResult = matchResult.NextMatch();
            }

            comboBox1.DataSource = _satellites;
            comboBox1.DisplayMember = "Name";
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            var comboBox = (ComboBox) sender;
            var satellites = comboBox.DataSource as List<Satellite>;
            if (satellites != null && comboBox.SelectedIndex > -1)
            {
                Satellite selectedSatellite = satellites[comboBox.SelectedIndex];
                Console.WriteLine("Selected satellite: " + selectedSatellite.Name);
            }
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            var textBox = (TextBox) sender;
            string text = textBox.Text;
            if (!string.IsNullOrWhiteSpace(text))
            {
                Satellite satellite =
                    _satellites.FirstOrDefault((s => s.Name.ToLower().StartsWith(text.ToLower())));
                if (satellite != null)
                {
                    Console.WriteLine("Found satellite: " + satellite);
                }
            }
        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {
            var textBox = (TextBox) sender;
            string text = textBox.Text;
            if (!string.IsNullOrWhiteSpace(text))
            {
                Satellite satellite =
                    _satellites.FirstOrDefault(
                        s => s.Numbers1.Any(t => t.StartsWith(text)) || s.Numbers2.Any(t => t.StartsWith(text)));
                if (satellite != null)
                {
                    Console.WriteLine("Found satellite: " + satellite);
                }
            }
        }
    }

    internal class Satellite
    {
        public string Name { get; set; }
        public string Line1 { get; set; }
        public string Line2 { get; set; }
        public List<string> Numbers1 { get; set; }
        public List<string> Numbers2 { get; set; }

        public override string ToString()
        {
            return string.Format("Name: {0}", Name);
        }
    }
}

Result:

Answer 2

If you don't want to use regex you could do something like this:

public List<string> GetSatelliteNames(string input)
{
    string[] split = input.split(new string[2] { "\n", "\r\n" });
    List<string> result = new List<string>();    
    foreach (var s in split)
    {
        string splitagain = s.split(new char[1] { ' ' });
        if (s[0] == "0") result.add(s[1]);
    }
    return result;
}

Answer 3

here is something that you can try quick and dirty that I have come up with.

1st place the file in a folder on your local hard drive.

2nd where I have filepath defined replace it with your actual file path and know how to use the @ symbol and what it means in C#

3rd notice how I used the string .Replace Method.. you will have to tweak it I just gave you an Idea I am not going to write the entire code for you.. good luck.

static void Main(string[] args)
{
    var fileName = string.Empty;
    var filePath = @"C:\Users\myfolder\Documents\RGReports\"; //for testing purposes only 
    List<string> listNames = new List<string>();
    string[] filePaths = Directory.GetFiles(@filePath);
    foreach (string file in filePaths)
    {
        if (file.Contains(".txt"))
        {
            fileName = file;
            using (StreamReader sr = File.OpenText(fileName))
            {
                //string s = String.Empty;
                var tempFile = sr.ReadToEnd();
                var splitFile = tempFile.Split(new string[] { "\r\n", "\n" }, StringSplitOptions.None);
                foreach (string str in splitFile)
                {
                    if (str.Length == 12)
                    {
                        listNames.Add(str.Substring(0, str.Length).Replace("0", "").Replace("1", "").Replace("2A",""));
                    }
                    Console.WriteLine(str);
                }
            }
        }
    }
}

Results will yield the following for names for example tested in a Console App

VANGUARD

TRANSIT

EXPLORER