public Command()

in src/Microsoft.Diagnostics.Runtime/src/Utilities/Command/Command.cs [109:194]
73 lines of code
12 McCabe index (conditional complexity)

        public Command(string commandLine, CommandOptions options)
        {
            Options = options;
            _commandLine = commandLine;

            // See if the command is quoted and match it in that case
            Match m = Regex.Match(commandLine, "^\\s*\"(.*?)\"\\s*(.*)");
            if (!m.Success)
                m = Regex.Match(commandLine, @"\s*(\S*)\s*(.*)"); // thing before first space is command

            ProcessStartInfo startInfo = new ProcessStartInfo(m.Groups[1].Value, m.Groups[2].Value)
            {
                UseShellExecute = false,
                RedirectStandardError = true,
                RedirectStandardOutput = true,
                ErrorDialog = false,
                CreateNoWindow = true,
                RedirectStandardInput = options.Input != null
            };

            Process = new Process { StartInfo = startInfo };
            Process.StartInfo = startInfo;
            _output = new StringBuilder();
            if (options.elevate)
            {
                options.useShellExecute = true;
                startInfo.Verb = "runas";
                options.currentDirectory ??= Environment.CurrentDirectory;
            }

            Process.OutputDataReceived += OnProcessOutput;
            Process.ErrorDataReceived += OnProcessOutput;

            if (options.environmentVariables != null)
            {
                // copy over the environment variables to the process startInfo options.
                foreach (KeyValuePair<string, string> pair in options.environmentVariables)
                {
                    // look for %VAR% strings in the value and substitute the appropriate environment variable.
                    string value = pair.Value;
                    if (value != null)
                    {
                        value = Environment.ExpandEnvironmentVariables(value);
                    }

                    startInfo.EnvironmentVariables[pair.Key] = value;
                }
            }

            startInfo.WorkingDirectory = options.currentDirectory ?? string.Empty;

            _outputStream = options.outputStream;
            if (options.outputFile != null)
            {
                _outputStream = File.CreateText(options.outputFile);
            }

            try
            {
                Process.Start();
            }
            catch (Exception e)
            {
                string msg = "Failure starting Process\r\n" +
                    "    Exception: " + e.Message + "\r\n" +
                    "    Cmd: " + commandLine + "\r\n";

                if (Regex.IsMatch(startInfo.FileName, @"^(copy|dir|del|color|set|cd|cdir|md|mkdir|prompt|pushd|popd|start|assoc|ftype)", RegexOptions.IgnoreCase))
                    msg += "    Cmd " + startInfo.FileName + " implemented by Cmd.exe, fix by prefixing with 'cmd /c'.";
                throw new Exception(msg, e);
            }

            if (!startInfo.UseShellExecute)
            {
                // startInfo asynchronously collecting output
                Process.BeginOutputReadLine();
                Process.BeginErrorReadLine();
            }

            // Send any input to the command
            if (options.input != null)
            {
                Process.StandardInput.Write(options.input);
                Process.StandardInput.Dispose();
            }
        }