private static string GetUserHomeDirOnUnix()

in src/PowerShell/Utilities/SharedUtilities.cs [58:107]
47 lines of code
12 McCabe index (conditional complexity)

        private static string GetUserHomeDirOnUnix()
        {
            if (IsWindowsPlatform())
            {
                throw new NotSupportedException();
            }

            if (!string.IsNullOrEmpty(s_homeEnvVar))
            {
                return s_homeEnvVar;
            }

            string username = null;
            if (!string.IsNullOrEmpty(s_lognameEnvVar))
            {
                username = s_lognameEnvVar;
            }
            else if (!string.IsNullOrEmpty(s_userEnvVar))
            {
                username = s_userEnvVar;
            }
            else if (!string.IsNullOrEmpty(s_lNameEnvVar))
            {
                username = s_lNameEnvVar;
            }
            else if (!string.IsNullOrEmpty(s_usernameEnvVar))
            {
                username = s_usernameEnvVar;
            }

            if (IsMacPlatform())
            {
                return !string.IsNullOrEmpty(username) ? Path.Combine("/Users", username) : null;
            }
            else if (IsLinuxPlatform())
            {
                if (LinuxNativeMethods.getuid() == LinuxNativeMethods.RootUserId)
                {
                    return "/root";
                }
                else
                {
                    return !string.IsNullOrEmpty(username) ? Path.Combine("/home", username) : null;
                }
            }
            else
            {
                throw new NotSupportedException();
            }
        }