Terminal Windows and Shell Access
The most common way to access a shell from a Linux graphicalinterface isusing a Terminal window. From a graphical interface, you can often accessvirtual terminals to get to a shell. With no graphical interface, with a text- based login you are typically dropped directly to a shell after login.
NOTE SUSE has traditionally supplied the K Desktop Environment, or KDE, as the default. Modern versions of SUSE supply both KDE anditsmain competitor, the GNOME desktop environment. The graphical examples in this book use the traditional KDE environment. Similarcommands exist within the GNOME environment.
Using Terminal Windows
Using Terminal Windows
Commands shown in Figure 3-1 illustratethat the current shell is the bash shell(/bin/bash), the current user is the desktop user who launched the window (ericfj),and the current directory is that user ’s home directory (/home/ericfj). The username(ericfj) and hostname (Brodgar) appear in the title bar.
The konsole window not only lets you access a shell, it also has controls for managing your shells. For example, click Session ➪ New Shell to open another shell on a different tab, or click Session ➪ New Window to open a new Terminal window.
Other key sequences for controlling Terminal windows include pressing Ctrl+Shift+f to show the window in full screen mode.Type Ctrl+d to exit the shell, which closes the current tab or entire Terminal window (if it’s the last tab). The konsole window sup-ports a handy program called screen.Select New Screen Session from the Session menutolaunch the screen program in a new tab.
Thekonsole window also supports profiles (select Settings ➪ Saveas Default to savethecurrent settings as your new defaults). Some profile settings are cosmetic(allow boldtext, cursor blinks, terminal bell, colors, images, and transparency). Other settings are func- tional. For example, by default, the terminal saves 1000 scrollback lines. Some people like to be able to scroll back further and are willing to give up more memory to allow that. See all the choices on the Settings menu for details.
Ifyou launch konsole manually, you can add options.Here are some examples:
$ konsole -e alsamixer Start terminal with alsamixer displayed
$ konsole --vt_sz 80x20 Start terminal 80 characters by 20 lines
$ konsole --profile name Start terminal using named session profile
Besides konsole, there are other terminal windows you can use such as xterm (basic terminal emulator that comes with the X Window System) or gnome-terminal (ter- minal emulator delivered with the GNOME desktop).The Enlightenment desktopproject offers the eterm terminal(which includes features such as message logs onthescreen background).
Using Virtual Terminals
Using Virtual Terminals
When SUSE boots in multi-user mode (runlevel 2, 3, or 5), six virtual consoles (known as tty1 through tty6) are created with text-basedlogins. If an X Window System desktopis running, X is probably running in virtual console 7. If X isn’t running, chances are you’re looking at virtual console 1.
From X, you can switch to another virtual console with Ctrl+Alt+F1, Ctrl+Alt+F2, and so on up to F6. From a text virtual console, you can switch using Alt+F1, Alt+F2, and so on. Press Alt+F7 to return to the X GUI. Each console allows you to log in using different user accounts. Switching to look at another console doesn’t affect running processes in any of them. When you switch to virtual terminal one through six, you see a login prompt similar to the following:
Welcome to openSUSE 10.3 (i586) – Kernel 2.6.22.5-29-default (tty2). localhostlogin:
Separate mingetty processes manage each virtual terminal. Type this command to see what mingetty processes look like before you log in to any virtual terminals:
$ ps awx| grep -v grep | grep mingetty
8573 tty1 | Ss+ | 0:00 /sbin/mingetty --noclear tty1 |
8574 tty2 | Ss+ | 0:00 /sbin/mingetty tty2 |
8577 tty3 | Ss+ | 0:00 /sbin/mingetty tty3 |
8579 tty5 | Ss+ | 0:00 /sbin/mingetty tty5 |
8580 tty6 | Ss+ | 0:00 /sbin/mingetty tty6 |
After I log in on the first console, mingetty handles my login and then fires up a bash shell:
$ ps awx| grep -v grep | grep tty
8573 tty1 | Ss+ | 0:00 /sbin/mingetty --noclear tty1 |
8574 tty2 | Ss+ | 0:00 /sbin/mingetty tty2 |
8577 tty3 | Ss+ | 0:00 /sbin/mingetty tty3 |
8579 tty5 | Ss+ | 0:00 /sbin/mingetty tty5 |
8580 tty6 | Ss+ | 0:00 /sbin/mingetty tty6 |
23841 tty1 | Ss+ | 0:00 -bash |
Virtual consolesare configured in the /etc/inittab file. You can have fewer or more virtual terminals by adding or deleting mingetty lines from that file.
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