3. Linux basics

3.1 Graphical environments

When you log in to a workstation you can (and probably will) work in a graphical environment. On most workstations you can choose between the KDE and Gnome (or Bluecurve) environments (possibly others). The first time you log in, you are presented with a brief welcome message, with instructions for getting further help. If you are not familiar with graphical envionments, you are advised to follow the instructions appearing on-screen.

3.2 Text environments

When you log in remotely, or open a terminal emulator on a workstation, you are presented with a text only environment. There are no fancy icons, menus, bars,...here, still there is much work you can do. You will probably find that many jobs are better (and/or easier and/or faster) done in a text environment.

What you interact with when you log in to a text environment is called your login shell. From here you have a wide range of programs available. We can roughly divide them as follows:

1. programs that start in the graphical environment - these are actually available/useful only if such graphical environment exists, i.e. they are certainly available from a local terminal emulator on a workstation; they may not be available if you logged in from a remote terminal
   • why should I log in graphically, then open a text environment, then launch a graphical application?
     Short answer: because you like it.
     Longer answer: because you find it simpler to type «mozilla &» than to navigate through three levels of menu to start your browser; or because this allows you to start your program with parameters not allowed within the menu interface (e.g. «nice opera www.your-site.net/ &»).
2. interactive text-mode programs, e.g. mc (file manager), pine (mail program), joe (editor): when you start such programs, you don't interact with the shell any more, but with the programs you started themselves, until you issue some «quit» command.
3. non-interactive text-mode program, e.g. ls (show directory contents), latex (text formatter), finger (show user information): these programs perform some action and «immediately» return control to the invoking shell

You can get help with most available programs via man: man pine will show you how to use the pine program (man man will show the manual for man itself). If you know what you want, but don't know what program you could use for it, try apropos keyword: this will search through all manual page headers for provided keyword.^3.1

Footnotes

...keyword.^3.1

For RedHat 8.0 users: you may need to export LANG=C to view correctly man pages.