OpenRCT2/openrct2.props

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <!-- 7z Task -->
  <UsingTask TaskName="_7z"
             TaskFactory="CodeTaskFactory"
             AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll" >
    <ParameterGroup>
      <Inputs Required="true" ParameterType="System.String" />
      <Output Required="true" ParameterType="System.String" />
    </ParameterGroup>
    <Task>
      <Using Namespace="System"/>
      <Using Namespace="System.Diagnostics"/>
      <Using Namespace="System.IO"/>
      <Code Type="Method" Language="cs">
        <![CDATA[
          public override bool Execute()
          {
              string appPath = Find7zPath();
              if (appPath == null)
              {
                  Log.LogError("Unable to find 7z.exe.");
                  return false;
              }

              string args = "a -tzip -mx9 -mtc=off \"" + Output + "\" \"" + Inputs + "\"";
              Log.LogMessage(MessageImportance.Normal, "7z " + args);

              var psi = new ProcessStartInfo(appPath, args);
              psi.CreateNoWindow = true;
              psi.UseShellExecute = false;
              psi.RedirectStandardOutput = true;
              psi.RedirectStandardError = true;
              var process = Process.Start(psi);
              process.WaitForExit();
              if (process.ExitCode != 0)
              {
                  string appError = process.StandardError.ReadToEnd();
                  appError = appError.Replace("\r\n", "\n");
                  appError = appError.Replace("\r", "\n");
                  appError = appError.Replace("\n", " ");
                  int colonIndex = appError.IndexOf(":");
                  if (colonIndex != -1)
                  {
                      appError = appError.Substring(colonIndex + 1);
                  }
                  appError = appError.Trim();
                  Log.LogError(appError);
                  return false;
              }

              string appOutput = process.StandardOutput.ReadToEnd();
              Log.LogMessage(MessageImportance.Normal, appOutput);
              return true;
          }

          private string Find7zPath()
          {
              const string DefaultAppFileName = "7z.exe";
              string DefaultAppPath = Path.Combine("7-Zip", DefaultAppFileName);

              // HACK needed as SpecialFolder.ProgramFiles returns x86 for a 32-bit process
              string programFiles = Path.Combine(Path.GetDirectoryName(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles)), "Program Files");
              string appPath = Path.Combine(programFiles, DefaultAppPath);
              if (File.Exists(appPath))
              {
                  return appPath;
              }

              programFiles = Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles);
              appPath = Path.Combine(programFiles, DefaultAppPath);
              if (File.Exists(appPath))
              {
                  return appPath;
              }
              
              programFiles = Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86);
              appPath = Path.Combine(programFiles, DefaultAppPath);
              if (File.Exists(appPath))
              {
                  return appPath;
              }
          
              string[] envPaths = Environment.GetEnvironmentVariable("PATH").Split(';');
              foreach (string envPath in envPaths)
              {
                  appPath = Path.Combine(envPath, DefaultAppFileName);
                  if (File.Exists(appPath))
                  {
                      return appPath;
                  }
              }
              
              return null;
          }
        ]]>
      </Code>
    </Task>
  </UsingTask>
</Project>