git:// protocol scheme handler for Windows

GitProtocolSchemeHandler.cs

using Microsoft.Win32;
using System.Text.RegularExpressions;
using System;

/**
 * @author nkmathew
 * @date July 10, 2017
 *
 * The program makes it possible to open "git://" like urls clicked from a console
 * emulator like ConEmu in your default browser as Windows doesn't recognize that
 * protocol scheme by default
 *
 * Build from the commandline or from an IDE.
 *
 * E.g
 *
 * C:\Windows\Microsoft.NET\Framework\v3.5\csc.exe GitProtocolHandler.cs
 */
class GitProtocolSchemeHandler {

  /**
   * Creates the registry key
   */
  static void RegisterAsHandler() {
    string programPath = System.Diagnostics.Process.
        GetCurrentProcess().MainModule.FileName;
    const string keyPath = "Software\\Classes\\git\\shell\\open\\command";
    RegistryKey keyCommand = Registry.CurrentUser.OpenSubKey(keyPath, true);
    if (keyCommand == null) {
      RegistryKey keySoftware = Registry.CurrentUser.OpenSubKey("Software", true);
      RegistryKey keyClasses = keySoftware.CreateSubKey("Classes");
      RegistryKey keyGit = keyClasses.CreateSubKey("git");
      RegistryKey keyShell = keyGit.CreateSubKey("shell");
      RegistryKey keyOpen = keyShell.CreateSubKey("open");
      keyCommand = keyOpen.CreateSubKey("command");
    }
    keyCommand.SetValue("", programPath + " %1");
    keyCommand.Close();
  }

  /**
   * Returns the GitHub repo url given the a repo url starting with "git://"
   */
  static string ProcessGitUrl(string url) {
    MatchCollection matches = Regex.Matches(url, "git://github.com/(.+)/(.+).git");
    int count = matches.Count;
    if (matches.Count != 0) {
      Group username = matches[0].Groups[1];
      Group reponame = matches[0].Groups[2];
      url = String.Format("https://github.com/{0}/{1}", username, reponame);
      return url;
    } else {
      return "";
    }
  }

  static void Main(string[] args) {
    RegisterAsHandler();
    if (args.Length > 0) {
      string url = args[0];
      url = ProcessGitUrl(url);
      if (url.Length != 0) {
        Console.WriteLine("Opening {0} in browser", url);
        System.Diagnostics.Process.Start(url);
      } else {
        Console.WriteLine("Error: Invalid github url found");
      }
    } else {
      Console.WriteLine("\nError: No url argument provided");
    }
  }

}