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/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
+}

Source/NETworkManager.Models/HostsFileEditor/HostsFileEntry.cs

@@ -0,0 +1,69 @@
+namespace NETworkManager.Models.HostsFileEditor;
+
+/// <summary>
+/// Class that represents a single entry in the hosts file.
+/// </summary>
+public class HostsFileEntry
+{
+    /// <summary>
+    /// Indicates whether the entry is enabled or not.
+    /// </summary>
+    public bool IsEnabled { get; init; }
+
+    /// <summary>
+    /// IP address of the host.
+    /// </summary>
+    public string IPAddress { get; init; }
+
+    /// <summary>
+    /// Host name(s) of the host. Multiple host names are separated by a
+    /// space (equal to the hosts file format).
+    /// </summary>
+    public string Hostname { get; init; }
+
+    /// <summary>
+    /// Comment of the host.
+    /// </summary>
+    public string Comment { get; init; }
+
+    /// <summary>
+    /// Line of the entry in the hosts file.
+    /// </summary>
+    public string Line { get; init; }
+
+    /// <summary>
+    /// Creates a new instance of <see cref="HostsFileEntry" />.
+    /// </summary>
+    public HostsFileEntry()
+    {
+
+    }
+
+    /// <summary>
+    /// Creates a new instance of <see cref="HostsFileEntry" /> with parameters.
+    /// </summary>
+    /// <param name="isEnabled">Indicates whether the entry is enabled or not.</param>
+    /// <param name="ipAddress">IP address of the host.</param>
+    /// <param name="hostname">Host name(s) of the host.</param>
+    /// <param name="comment">Comment of the host.</param>
+    public HostsFileEntry(bool isEnabled, string ipAddress, string hostname, string comment)
+    {
+        IsEnabled = isEnabled;
+        IPAddress = ipAddress;
+        Hostname = hostname;
+        Comment = comment;
+    }
+
+    /// <summary>
+    /// Creates a new instance of <see cref="HostsFileEntry" /> with parameters.
+    /// </summary>
+    /// <param name="isEnabled">Indicates whether the entry is enabled or not.</param>
+    /// <param name="ipAddress">IP address of the host.</param>
+    /// <param name="hostname">Host name(s) of the host.</param>
+    /// <param name="comment">Comment of the host.</param>
+    /// <param name="line">Line of the entry in the hosts file.</param>
+    public HostsFileEntry(bool isEnabled, string ipAddress, string hostname, string comment, string line) : this(isEnabled, ipAddress, hostname, comment)
+    {
+        Line = line;
+    }
+}

Source/NETworkManager.Models/Lookup/OUILookup.cs

@@ -22,7 +22,7 @@ public static class OUILookup
     /// </summary>
     static OUILookup()
     {
-        OUIInfoList = new List<OUIInfo>();
+        OUIInfoList = [];
 
         var document = new XmlDocument();
         document.Load(OuiFilePath);

Source/NETworkManager.Models/Lookup/PortLookup.cs

@@ -19,7 +19,7 @@ public static class PortLookup
     /// </summary>
     static PortLookup()
     {
-        PortList = new List<PortLookupInfo>();
+        PortList = [];
 
         var document = new XmlDocument();
         document.Load(PortsFilePath);