In the early development of Linux, Shell is the only usable tools, Linux users are entered in the Shell text commands, and view text output; if necessary, Shell also display some basic graphics.
Today Linux environment is completely different, almost all Linux distributions use some sort of graphical desktop environments (such as GNOME, KDE, Unity, etc.), which makes Shell native entrance is hidden, as if into the Shell became difficult.
Into the Linux console
A method of entering the Shell is to make Linux system to exit the graphical interface mode, enter console mode, so that, on the display only a simple white text with a "black screen", as it was before the graphical interface. This mode is called Linux Console (Console).
Modern Linux system is automatically created when you start several virtual console (Virtual Console), in which a program for graphical desktop use, the other way to retain the native console. Virtual Console is actually a virtual terminal (Virtual Terminal) Linux system running in memory.
From the graphical interface mode to enter the console mode is also very simple, often press the Ctrl + Alt + Fn(n=1,2,3,4,5...)shortcut key will be able to switch back and forth.
For example, CentOS is created when you start six virtual consoles, press the shortcut key Ctrl + Alt + Fn(n=2,3,4,5,6)to switch from the graphical interface mode to console mode, press Ctrl + Alt + F1can then switch back to the graphical interface mode from the console mode. Can be found on the 1st console is a graphical desktop programs occupied.
The figure is to enter the console mode:
Enter your user name and password, log on after the success can enter the Shell. $Is the command prompt, we can enter the Shell command behind it.
In the GUI mode, enter the password often appears as *, there are several password characters on the show a few *; while in console mode, enter the password nothing will show, as if the keys were invalid, this please Do not panic, as long as the correct password is entered will be able to log on.
GUI is a program that will take up CPU time and memory space, when Linux as a server system, after the installation is completed, should be allowed to run Linux in console mode to conserve server resources. It is for this reason, many servers do not even install a graphical interface, administrators can use the command to complete the operation.
Using Terminal
Another method is to use the terminal to enter the Shell Linux desktop environment simulation package (Terminal emulation package), that is, we often say that the terminal (Terminal), so you can use the graphical desktop Shell.
In CentOS an example, the terminal can find the "Application" menu, as shown below:
Figure: In the "Favorite" and "Tools" category can be found terminal
After opening the terminal, you can enter the Shell command:
CentOS default GUI program is GNOME, the simulation package is GNOME terminal comes.
In addition GNOME terminal, Linux as well as other terminal emulation package, for example:
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xterm terminal
The oldest and most basic of X Windows desktop program comes with a terminal emulation package is xterm. xterm X Windows appear before it has been in existence, included by default in most of the X Windows. xterm although not too many dazzling features, but it does not run too many resources, so xterm is still very common in the Linux distribution designed for older hardware, such as fluxbox graphical desktop environment to use it as the default terminal emulation package. -
Konsole terminal
KDE desktop project also developed its own terminal emulation package, called Konsole. Konsole incorporates basic xterm properties and characteristics similar to some of the more advanced Windows applications.