Feature: Hosts File Editor

Source/GlobalAssemblyInfo.cs

@@ -6,5 +6,5 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 
-[assembly: AssemblyVersion("2025.1.18.0")]
-[assembly: AssemblyFileVersion("2025.1.18.0")]
+[assembly: AssemblyVersion("2025.3.16.0")]
+[assembly: AssemblyFileVersion("2025.3.16.0")]

Source/NETworkManager.Localization/Resources/Strings.resx

@@ -3879,4 +3879,16 @@ Right-click for more options.</value>
   <data name="ProfileFile" xml:space="preserve">
     <value>Profile file</value>
   </data>
+  <data name="ApplicationName_HostsFileEditor" xml:space="preserve">
+    <value>Hosts File Editor</value>
+  </data>
+  <data name="HostsFileEditor" xml:space="preserve">
+    <value>Hosts File Editor</value>
+  </data>
+  <data name="HostsFileEditorAdminMessage" xml:space="preserve">
+    <value>To edit the hosts file, the application must be started with elevated rights!</value>
+  </data>
+  <data name="Comment" xml:space="preserve">
+    <value>Comment</value>
+  </data>
 </root>

Source/NETworkManager.Models/AWS/AWSProfile.cs

@@ -6,10 +6,10 @@ public static class AWSProfile
 {
     public static List<AWSProfileInfo> GetDefaultList()
     {
-        return new List<AWSProfileInfo>
-        {
-            new(false, "default", "eu-central-1"),
-            new(false, "default", "us-east-1")
-        };
+        return
+        [
+            new AWSProfileInfo(false, "default", "eu-central-1"),
+            new AWSProfileInfo(false, "default", "us-east-1")
+        ];
     }
 }

Source/NETworkManager.Models/AWS/AWSProfileInfo.cs

@@ -1,7 +1,7 @@
 namespace NETworkManager.Models.AWS;
 
 /// <summary>
-///     Class is used to store informations about an AWS profile.
+///     Class is used to store information about an AWS profile.
 /// </summary>
 public class AWSProfileInfo
 {
@@ -15,7 +15,7 @@ public AWSProfileInfo()
     /// <summary>
     ///     Create an instance of <see cref="AWSProfileInfo" /> with parameters.
     /// </summary>
-    /// <param name="IsEnabled"><see cref="IsEnabled" />.</param>
+    /// <param name="isEnabled"><see cref="IsEnabled" />.</param>
     /// <param name="profile"><see cref="Profile" />.</param>
     /// <param name="region"><see cref="Region" />.</param>
     public AWSProfileInfo(bool isEnabled, string profile, string region)

Source/NETworkManager.Models/ApplicationManager.cs

@@ -1,8 +1,8 @@
-using System;
+using MahApps.Metro.IconPacks;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Windows.Controls;
-using MahApps.Metro.IconPacks;
 
 namespace NETworkManager.Models;
 
@@ -92,6 +92,9 @@ public static Canvas GetIcon(ApplicationName name)
             case ApplicationName.SNTPLookup:
                 canvas.Children.Add(new PackIconMaterial { Kind = PackIconMaterialKind.ClockCheckOutline });
                 break;
+            case ApplicationName.HostsFileEditor:
+                canvas.Children.Add(new PackIconMaterial { Kind = PackIconMaterialKind.FileEditOutline });
+                break;
             case ApplicationName.DiscoveryProtocol:
                 canvas.Children.Add(new PackIconMaterial { Kind = PackIconMaterialKind.SwapHorizontal });
                 break;

Source/NETworkManager.Models/ApplicationName.cs

@@ -90,6 +90,11 @@ public enum ApplicationName
     /// </summary>
     SNTPLookup,
 
+    /// <summary>
+    /// Hosts file editor application.
+    /// </summary>
+    HostsFileEditor,
+
     /// <summary>
     ///     Discovery protocol application.
     /// </summary>

Source/NETworkManager.Models/Export/ExportManager.HostsFileEntry.cs

@@ -0,0 +1,98 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Xml.Linq;
+using NETworkManager.Models.HostsFileEditor;
+using Newtonsoft.Json;
+
+namespace NETworkManager.Models.Export;
+
+public static partial class ExportManager
+{
+    /// <summary>
+    ///     Method to export objects from type <see cref="HostsFileEntry" /> to a file.
+    /// </summary>
+    /// <param name="filePath">Path to the export file.</param>
+    /// <param name="fileType">Allowed <see cref="ExportFileType" /> are CSV, XML or JSON.</param>
+    /// <param name="collection">Objects as <see cref="IReadOnlyList{HostsFileEntry}" /> to export.</param>
+    public static void Export(string filePath, ExportFileType fileType, IReadOnlyList<HostsFileEntry> collection)
+    {
+        switch (fileType)
+        {
+            case ExportFileType.Csv:
+                CreateCsv(collection, filePath);
+                break;
+            case ExportFileType.Xml:
+                CreateXml(collection, filePath);
+                break;
+            case ExportFileType.Json:
+                CreateJson(collection, filePath);
+                break;
+            case ExportFileType.Txt:
+            default:
+                throw new ArgumentOutOfRangeException(nameof(fileType), fileType, null);
+        }
+    }
+
+    /// <summary>
+    ///     Creates a CSV file from the given <see cref="HostsFileEntry" /> collection.
+    /// </summary>
+    /// <param name="collection">Objects as <see cref="IReadOnlyList{HostsFileEntry}" /> to export.</param>
+    /// <param name="filePath">Path to the export file.</param>
+    private static void CreateCsv(IEnumerable<HostsFileEntry> collection, string filePath)
+    {
+        var stringBuilder = new StringBuilder();
+
+        stringBuilder.AppendLine(
+            $"{nameof(HostsFileEntry.IsEnabled)},{nameof(HostsFileEntry.IPAddress)},{nameof(HostsFileEntry.Hostname)},{nameof(HostsFileEntry.Comment)}");
+
+        foreach (var info in collection)
+            stringBuilder.AppendLine($"{info.IsEnabled},{info.IPAddress},{info.Hostname},{info.Comment}");
+
+        File.WriteAllText(filePath, stringBuilder.ToString());
+    }
+
+    /// <summary>
+    ///     Creates a XML file from the given <see cref="HostsFileEntry" /> collection.
+    /// </summary>
+    /// <param name="collection">Objects as <see cref="IReadOnlyList{HostsFileEntry}" /> to export.</param>
+    /// <param name="filePath">Path to the export file.</param>
+    private static void CreateXml(IEnumerable<HostsFileEntry> collection, string filePath)
+    {
+        var document = new XDocument(DefaultXDeclaration,
+            new XElement(ApplicationName.HostsFileEditor.ToString(),
+                new XElement(nameof(HostsFileEntry) + "s",
+                    from info in collection
+                    select
+                        new XElement(nameof(HostsFileEntry),
+                            new XElement(nameof(HostsFileEntry.IsEnabled), info.IsEnabled),
+                            new XElement(nameof(HostsFileEntry.IPAddress), info.IPAddress),
+                            new XElement(nameof(HostsFileEntry.Hostname), info.Hostname),
+                            new XElement(nameof(HostsFileEntry.Comment), info.Comment)))));
+
+        document.Save(filePath);
+    }
+
+    /// <summary>
+    ///     Creates a JSON file from the given <see cref="HostsFileEntry" /> collection.
+    /// </summary>
+    /// <param name="collection">Objects as <see cref="IReadOnlyList{HostsFileEntry}" /> to export.</param>
+    /// <param name="filePath">Path to the export file.</param>
+    private static void CreateJson(IReadOnlyList<HostsFileEntry> collection, string filePath)
+    {
+        var jsonData = new object[collection.Count];
+
+        for (var i = 0; i < collection.Count; i++)
+            jsonData[i] = new
+            {
+                collection[i].IsEnabled,
+                collection[i].IPAddress,
+                collection[i].Hostname,
+                collection[i].Comment
+            };
+
+        File.WriteAllText(filePath, JsonConvert.SerializeObject(jsonData, Formatting.Indented));
+    }
+}

Source/NETworkManager.Models/HostsFileEditor/HostsFileEditor.cs

@@ -0,0 +1,135 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using log4net;
+using NETworkManager.Utilities;
+
+namespace NETworkManager.Models.HostsFileEditor;
+
+public static class HostsFileEditor
+{
+#region Events
+    public static event EventHandler HostsFileChanged;
+
+    private static void OnHostsFileChanged()
+    {
+        Log.Debug("OnHostsFileChanged - Hosts file changed.");
+        HostsFileChanged?.Invoke(null, EventArgs.Empty);
+    }
+    #endregion
+
+    #region Variables
+    private static readonly ILog Log = LogManager.GetLogger(typeof(HostsFileEditor));
+
+    private static readonly FileSystemWatcher HostsFileWatcher;
+
+    /// <summary>
+    /// Path to the hosts file.
+    /// </summary>
+    private static string HostsFilePath => Path.Combine(Environment.SystemDirectory, "drivers", "etc", "hosts");
+
+    /// <summary>
+    /// Example values in the hosts file that should be ignored.
+    /// </summary>
+    private static readonly HashSet<(string IPAddress, string Hostname)> ExampleValuesToIgnore =
+    [
+        ("102.54.94.97", "rhino.acme.com"),
+        ("38.25.63.10", "x.acme.com")
+    ];
+
+    /// <summary>
+    /// Regex to match a hosts file entry with optional comments, supporting IPv4, IPv6, and hostnames
+    /// </summary>
+    private static readonly Regex HostsFileEntryRegex = new(RegexHelper.HostsEntryRegex);
+
+    #endregion
+
+    #region Constructor
+
+    static HostsFileEditor()
+    {
+        // Create a file system watcher to monitor changes to the hosts file
+        try
+        {
+            Log.Debug("HostsFileEditor - Creating file system watcher for hosts file...");
+
+            // Create the file system watcher
+            HostsFileWatcher = new FileSystemWatcher();
+            HostsFileWatcher.Path = Path.GetDirectoryName(HostsFilePath) ?? throw new InvalidOperationException("Hosts file path is invalid.");
+            HostsFileWatcher.Filter = Path.GetFileName(HostsFilePath) ?? throw new InvalidOperationException("Hosts file name is invalid.");
+            HostsFileWatcher.NotifyFilter = NotifyFilters.LastWrite;
+
+            // Maybe fired twice. This is a known bug/feature.
+            // See: https://stackoverflow.com/questions/1764809/filesystemwatcher-changed-event-is-raised-twice
+            HostsFileWatcher.Changed += (_, _) => OnHostsFileChanged();
+
+            // Enable the file system watcher
+            HostsFileWatcher.EnableRaisingEvents = true;
+
+            Log.Debug("HostsFileEditor - File system watcher for hosts file created.");
+        }
+        catch (Exception ex)
+        {
+            Log.Error("Failed to create file system watcher for hosts file.", ex);
+        }
+    }
+    #endregion
+
+    #region Methods
+    public static Task<IEnumerable<HostsFileEntry>> GetHostsFileEntriesAsync()
+    {
+        return Task.Run(GetHostsFileEntries);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    private static IEnumerable<HostsFileEntry> GetHostsFileEntries()
+    {
+        var hostsFileLines = File.ReadAllLines(HostsFilePath);
+
+        // Parse the hosts file content
+        var entries = new List<HostsFileEntry>();
+
+        foreach (var line in hostsFileLines)
+        {
+            var result = HostsFileEntryRegex.Match(line.Trim());
+
+            if (result.Success)
+            {
+                Log.Debug("GetHostsFileEntries - Line matched: " + line);
+
+                var entry = new HostsFileEntry
+                {
+                    IsEnabled = !result.Groups[1].Value.Equals("#"),
+                    IPAddress = result.Groups[2].Value,
+                    Hostname = result.Groups[3].Value.Replace(@"\s", "").Trim(),
+                    Comment = result.Groups[4].Value.TrimStart('#',' '),
+                    Line = line
+                };
+
+                // Skip example entries
+                if(!entry.IsEnabled)
+                {
+                    if (ExampleValuesToIgnore.Contains((entry.IPAddress, entry.Hostname)))
+                    {
+                        Log.Debug("GetHostsFileEntries - Matched example entry. Skipping...");
+                        continue;
+                    }
+                }
+
+                entries.Add(entry);
+            }
+            else
+            {
+                Log.Debug("GetHostsFileEntries - Line not matched: " + line);
+            }
+        }
+
+        return entries;
+    }
+    #endregion
+}