Tips for Ubuntu

  Issues with live usb are not in regular OS and the other way, Live usb max space 4G , OS 11G for this flash drive (flash drive size 15G)
1)sudo apt-get install gdm
  sudo service gdm restart
  To switch between gdm and lightdm: "sudo dpkg-reconfigure gdm"
2)Tweaks to custome Ubuntu:<a href="http://www.noobslab.com/2013/04/tweaksthings-to-do-after-install-of.html">http://www.noobslab.com/2013/04/tweaksthings-to-do-after-install-of.html</a> 
3)Install nautilus actions configuration tool (each user has his own so they can modify or add Context (right click))
   Add (explore the options to edit):
   1)Context label: Open Remote Terminal (you have to be in the default home directory)
     Command Path: gnome-terminal
     Command Parameters: -e "ssh -l %b %h"
     Schemes: SSH
   2)Context label: Open Terminal
     Command Path: gnome-terminal
     Command Parameters: --working-directory=%d/%b
     Schemes: *
     Note: actions are save local to each user go to /home/.local/share/file-manager/actions/
 4)To change what to be displayed at the login screen edit (you can use also gedit)
   sudo nano /etc/lightdm/lightdm.conf
 5)To make the system stop displaying error massages edit
    sudo gedit /etc/default/apport
    change enabled to 0
    sudo service apport stop
 6)To update or upgrade or install
    sudo apt-get update
    sudo apt-get upgrade 
    sudo apt-get install yum , (i am using yum as an example)
 7)To clean the system after updates and install
    sudo apt-get autoremove
    sudo apt-get autoclean
 8)To bypass Ubuntu install massage and substitute it with your own message until system loads
    go to the root folder (insert the USB in another operating system and you will see the root folder i am not sure this can be done from inside Ubuntu it self)
    open syslinux directory and make sure syslinux.cfg is not read only and change it to this
    if using live usb with allocated space 32-bit , (without "( , )")
    (
	 default live
	 label live
  	 say Booting an Ubuntu Live session...
  	 kernel /casper/vmlinuz
     append  file=/cdrom/preseed/ubuntu.seed boot=casper persistent initrd=/casper/initrd.lz quiet splash noprompt --
    )
    for 64-bit systems
    (
     default live label live say Booting an Ubuntu Live session... kernel /casper/vmlinuz.efi append file=/cdrom/preseed/ubuntu.seed boot=casper persistent initrd=/casper/initrd.lz quiet splash noprompt --
    )
    if not using live usb with allocated space then remove the word persistent
	link: http://askubuntu.com/questions/47522/how-to-bypass-try-it-install-screen-when-booting-from-usb-live-session-wit
 9)If users can not shutdown the computer then do the following ( it goes to log in screen)
    sudo gedit /usr/share/polkit-1/actions/org.freedesktop.consolekit.policy
    the two blocks for the multiple users will have auth_admin _keep change both of them to yes
    Then:
    sudo chmod u+s /sbin/shutdown
    use the command sudo shutdown -h now to shutdown the computer (not init 0)
    You might need to restart the computer before the effects take change, Also if you are in this case you can click ctrl + alt + f1 and the screen will go to a console command screen, login as root and type init 0 to shut down and init 6 to restart and if you want to go back to UI press ctrl+alt+f7 (also note that from f1 to f6 each one is a console command by it self)
 10)To use ssh open a folder and click in the menu and choose connect to a server and enter:
    ssh://(username)@(host name)
    you do not have to enter the username here if you want (ssh://(hostname)
 11)If you want to clear ssh history then go to  /home/.config/nautilus and delete or edit servers
 12)When you have file manger open go to file-> preferences and go to behavior tab and check "include a delete .."  to add option delete to the right menu (recommended)
 13)If when you move a file or folder to trash and it does not go to the trash you will find it in /.Trash(number associated with each user, so the owner of that file or root can access it or delete it ) , so it is recommend to add the delete option so you delete the files rigaht away 
 14)Set a password for root once you create the system
     sudo passwd root
 15)You can execute shell files in terminals by ./example.sh 
 16)To run a c++ file you run command compile the program by command
     g++ example.cpp
     and it will create a file in the same location called a.out to execute it
     ./a.out 
     that will give you the output in the terminal, to get the executable file with different name: 
     g++ example.cpp -o output
     then
     ./output
 17)Install flash player
        sudo apt-get install flashplugin-installer
 18)Install restricted extras( mp3, fonts, java, etc..)
        sudo apt-get install ubuntu-restricted-extras 
 19)Install compression tools
        sudo apt-get install p7zip-rar p7zip-full unace unrar zip unzip sharutils rar uudeview mpack arj cabextract file-roller
 20)ctrl+alt+t to open a terminal, you can right click on the terminal icon in the luncher and check lock to luncher to lock a shortcut for the terminal in the luncher 
 21)To save space in the settings go to privacy and make recored activities off and search online off
 22)If any of the sudo apt-get install do not work then use the Ubuntu software center (it has the same programs) and when you find a program and try to install it, it will ask you do you trust this source, say yes and then sudo apt-get install should work or you can use the Ubuntu software center
 23)To remove a program example yum
       sudo apt-get remove --purge yum
       sudo apt-get clean
 24)ctrl+h to show hidden folder
 25)To switch to another user for example root in terminal type in 
       su root