Ubuntu – a tty, and how to access a tty

Finally found it! As it turns out, I was searching for the wrong term. Apparently the TTYs run on a framebuffer, which is what the colors get changed in.

From this blog post but customized to use the railscasts theme colors, add the following to ~/.bashrc:

if [ "$TERM" = "linux" ]; then
    echo -en "\e]P0232323" #black
    echo -en "\e]P82B2B2B" #darkgrey
    echo -en "\e]P1D75F5F" #darkred
    echo -en "\e]P9E33636" #red
    echo -en "\e]P287AF5F" #darkgreen
    echo -en "\e]PA98E34D" #green
    echo -en "\e]P3D7AF87" #brown
    echo -en "\e]PBFFD75F" #yellow
    echo -en "\e]P48787AF" #darkblue
    echo -en "\e]PC7373C9" #blue
    echo -en "\e]P5BD53A5" #darkmagenta
    echo -en "\e]PDD633B2" #magenta
    echo -en "\e]P65FAFAF" #darkcyan
    echo -en "\e]PE44C9C9" #cyan
    echo -en "\e]P7E5E5E5" #lightgrey
    echo -en "\e]PFFFFFFF" #white
    clear #for background artifacting
fi

The virtual terminals (the ones you get to with Ctrl Alt F1-9) go back to the roots of Linux. Remember that Linux was originally a command-line only system and designed for multiple users. The idea was that each user could log into a single tty. This would not happen on the same physical machine of course, think of servers that many computer terminals would connect to. Each user would connect using a different computer and the server log them in to a tty.

This has nothing to do with the tty command which is part of coreutils. The tty command is simply a tool that lets you know the name of the terminal you are currently using.

The "terminal" (actually called a "terminal emulator") is simply a GUI program that mimics the old behavior. It lets you run a shell (bash in the default Ubuntu) from within your X session.

The main point is that both the virtual terminals and the terminal emulators provide you with a command line interface, a shell. They are basically the same thing. The only important difference from a practical point of view is that the terminal emulators run interactive, non-login shells while if you drop into a tty and login there, you will run an interactive, login shell. For more information on the differences between these two types of shell, see here.

I suggest you also read this excellent Q&A on Unix & Linux:

What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'?.