为什么该bash脚本不能在Ubuntu上执行，但是可以在在线环境上执行呢？

我不知道为什么这不能在Ubuntu上正常工作。当我在CompileOnline上执行脚本时，它的效果很好。但是当我在本地服务器上运行它时，它没有显示主菜单，而是从顶部开始读取命令列表。

该脚本应该是菜单系统。根据用户选择的内容，将发生什么动作。也有注释，因此您可以查看每个代码部分的功能。

    #!/bin/su

    # Ititialization

    function installsamba {
      sudo apt-get update
      sudo apt-get -y dist-upgrade
      sudo apt-get -y install git build-essential libacl1-dev libattr1-dev libblkid-dev libgnutls-dev libreadline-dev python-dev python-dnspython gdb pkg-config libpopt-dev libldap2-dev dnsutils libbsd-dev attr krb5-user docbook-xsl libcups2-dev acl
      git clone git://git.samba.org/samba.git samba-master
      cd samba-master
      ./configure
      sudo make
      sudo make install
      sudo rm -f -R samba-master
      sed -i "5i PATH=$PATH:/usr/local/samba/bin" ~/.bashrc
      sed -i "5i PATH=$PATH:/usr/local/samba/sbin" ~/.bashrc
      sudo sed -i "5i PATH=$PATH:/usr/local/samba/bin" /root/.bashrc
      sudo sed -i "5i PATH=$PATH:/usr/local/samba/sbin" /root/.bashrc
      mainmenu
      }

    # This installs all of the necessary components for building samba then downloads samba from git.
    # After that it then compiles and installs samba and returns to the main menu.

    function installvsftpd {
      sudo apt-get update
      sudo apt-get -y dist-upgrade
      sudo apt-get -y install vsftpd
      mainmenu
      }

    # This installs VSFTPd and return to the main menu.


    function installwebmin {
      wget http://www.webmin.com/download/deb/webmin-current.deb
      sudo apt-get update
      sudo apt-get -y dist-upgrade
      sudo dpkg -i webmin-current.deb
      sudo apt-get -y install -f
      rm webmin-current.deb
      mainmenu
      }

    # This installs the current version of WebMin and then returns to the main menu.

    function updatesystem {
      sudo apt-get update
      sudo apt-get -y dist-upgrade
      echo "Update Complete!"
      echo "It may be wise to restart your computer..."
      read -N 1
      clear
      mainmenu
      }

    # This install the latest updates for the system and then returns to the main menu.


    function configuresambaforactivedirectory {
      sudo sed -i.original -r '/[ \t]\/[ \t]/{s/(ext4[\t ]*)([^\t ]*)/\1\2,user_xattr,acl,barrier=1/}' /etc/fstab
      mount -a
      sudo /usr/local/samba/bin/samba-tool domain provision
      sudo mv /etc/krb5.conf /etc/krb5.conf.bak
      sudo cp /usr/local/samba/private/krb5.conf /etc/krb5.conf
      sudo sed -i "13i sudo /usr/local/samba/sbin/samba" /etc/rc.local
      sudo /usr/local/samba/sbin/samba
      domaincontrolleryorn
      }

    # This function runs all of the necessary actions to make samba a domain controller.


    function domaincontrolleryorn {
      echo "did you set this instalation as a primary domain controller?"
      echo ""
      echo "If you select yes then it will upgrade the forrest and domain to"
      echo "Server 2008 R2 levels. This may break compatibility with earlier"
      echo "versions of Windows Server. You can alwayse manually change the levels"
      echo "if you wish... Press wisely!"
      echo ""
      echo "Y or N:"
      read -N 1 -p "Y or N:" domaincontrolleryesorno
      if [ $domaincontrolleryesorno = "Y" ]; then
       upgradeforrestanddomain
       elif [ "$$domaincontrolleryesorno" = "N" ]; then
                clear
                echo "Samba configuration complete!"
                echo "Press any key to continue..."
                read -N 1
                mainmenu
        elif [ "$$domaincontrolleryesorno" = "n" ]; then
                clear
                echo "Samba configuration complete!"
                echo "Press any key to continue..."
                read -N 1
                mainmenu
        elif [ "$$domaincontrolleryesorno" = "y" ]; then
                upgradeforrestanddomain
        else
          echo "Please press either Y or N!!!"
          echo ""
          echo "Press any key to continue..."
          read -N 1
          clear
          domaincontrolleryorn
        fi
      }

# This asks the user if he or she would like to upgrade the domain and forrest level.
# If yes then it roputs the user to the code below. If not then the user is taken to the main menu.

    function upgradeforrestanddomain  {
      sudo /usr/local/samba/bin/samba-tool domain level raise --domain-level=2008_R2
      sudo /usr/local/samba/bin/samba-tool domain level raise --forest-level=2008_R2
      sudo /usr/local/samba/bin/samba-tool domain passwordsettings set --complexity=off
      echo "Domain Controller setup has completed!"
      echo ""
      echo "Press any key to return to the main menu..."
      read -N 1
      clear
      mainmenu
      }


    # This function upgrade the Domain and Forrest level to (Server) 2008_R2.
    # Acceptable levels are 2008 and 2008 R2. The default is 2003.


    function quitprogram {
      clear
      echo "Sorry to see you go... :("
      exit
      }

    # This is a simple good by program closer.
    # Oh, did I mention that it stops the program?


    function mainmenu {
      echo "Press 1 to update your system"
      echo "Press 2 to install samba"
      echo "Press 3 to install vsFTPd"
      echo "Press 4 to install the current version of Webmin"
      echo "Press 5 to configure samba for Active Directory"
      echo "Press x to exit the script"
      read -N 1 -p "Input Selection:" mainmenuinput
      if [ "$mainmenuinput" = "1" ]; then
                updatesystem
            elif [ "$mainmenuinput" = "2" ]; then
                installsamba
            elif [ "$mainmenuinput" = "3" ]; then
                installvsftpd
            elif [ "$mainmenuinput" = "4" ]; then
                installwebmin
            elif [ "$mainmenuinput" = "5" ]; then
                configuresambaforactivedirectory
            elif [ "$mainmenuinput" = "x" ];then
                quitprogram
            elif [ "$mainmenuinput" = "X" ];then
                quitprogram
            else
                echo "You have entered an invallid selection!"
                echo "Please try again!"
                echo ""
                echo "Press any key to continue..."
                read -N 1
                clear
                mainmenu
            fi
    }

    mainmenu

    # This executes the main menu function.
    # Let the fun begin!!!! WOOT WOOT!!!!

有人可以帮我吗？