A command line interface (CLI) is a way of interacting with an operating system or programs using text commands. As opposed to graphical user interfaces (GUI), CLI, due to its nature, is heavily keyboard oriented. Despite a steeper learning curve, this way of interaction has a wide range of benefits and is therefore preferred by many users.
Since most Slackware configuration and administration is performed using the command line interface, it is highly recommended to understand and feel comfortable using them. An additional advantage is that 99% of the commands are universal for most Linux distributions. Things you learn here will most probably be applicable elsewhere.
The following are some of the advantages to using CLI:
Being very powerful and flexible, CLI commands can also be unforgiving and potentially harmful to your system. Please remember about the following:
A program that provides a command line interface is called a shell
and is loaded when a user logs in to a system. The default shell in Slackware is called Bash
(Bourne-again shell). Although other shells will be briefly discussed in Chapter 3, the CLI manual will focus predominantly on Bash, the most common shell on today's Linux systems. Once you've started the X window system, you can access the shell via virtual terminals
which can be opened by pressing Alt+F2 through F6 (the 7th being the current X session).
A more convenient and common solution, however, is to access the shell via terminal emulators
. Slackware ships with the following terminal emulators:
There are many more terminal emulators available from Slackbuilds.org. Some popular ones are:
Despite the fact that ultimately they all provide access to the shell, some of them offer unique features that may be appealing to you so it is worth doing some research on them.
Another CLI tool that may come in handy, especially if you are working on remote systems, are terminal multiplexers which make it possible to run multiple terminal sessions within one virtual terminal or terminal emulator window. Two most popular terminal multiplexers are screen
(comes with Slackware) and tmux
(available from SlackBuilds).
Next Chapter: First Steps