each terminali.e., which codes to send to produce different effects and which codes can be received from the terminal. Fedora's terminfo database has entries for about 2,500 different hardware terminals and terminal programs that have been produced through the years.
curses keeps two buffers areas of memory arranged in the same size and layout as the screento store the current terminal screen contents and the desired display. When vi needs to update the screen, it updates the display buffer; curses compares the two buffers to determine the minimum number of commands it can send to the terminal to produce the desired display. It then sends the appropriate codes from the terminal database ( terminfo / termcap ) to update the terminal, copies the display buffer to the terminal buffer, and repeats the process.
The version of vi used by Fedora Core is Vim (Vi iMproved), which adds many, many features to the traditional vi capabilities; the commands covered in this chapter outline only the basics. Vim offers syntax highlighting, macro recording, support for multiple character sets, accents, right-to-left text, and many other features, making it a useful text editor for programming, scripting, and editing system files.
Vim can be configured by creating a .vimrc file; for details, type :help vimrc-intro within Vim.
4.4.3.1. ...using vi with a GUI?
If you execute gvim instead of vi , a window will appear with a full graphical user interfaceincluding pull-down menus and a toolbaras shown in Figure 4-5 . Using the File>Save menu option, clicking on the Save toolbar icon, or typing the vi save command ( :w) will perform the same operation.
Figure 4-5. gvim: vi with a GUI
4.4.3.2. ...using other text editors?
In addition to vi , Fedora ships with a plethora of other text editors, including:
? nano (an improved clone of the easy-to-use editor Pico )
? mcedit
? joe (the commands jstar , jmacs , or jpico will start joe configured to emulate WordStar , emacs , or Pico ).
? emacs and emacs-x
? kedit and gedit
All of these text editors are capable of editing just about any text file. Each has its advantages and disadvantages.
Since the choice of editor is very personal, take some time to experiment with each of the editors to see which one you prefer. In any case, I'd recommend knowing the basics of vi so that you can always fall back to it if you encounter a situation where your favorite editor is unavailable.
4.4.4. Where Can I Learn More?
? The Vim web site: http://www.vim.org/
? The vi help file and online tutorial: start vi , then type :help and press Enter
Fedora can be booted into different runlevels , each of which starts a specific collection of software for a particular purpose. The most commonly used are runlevel 3, which starts the system with a character-based user interface, and runlevel 5, which starts the system with a graphical user interface. Table 4-11 lists the standard runlevels.
Table 4-11. Standard runlevels
| Runlevel | Description | Purpose |
| s (or S) | Single-user maintenance mode | Emergency system recovery work |
| 0 | Halt | Stops the system |
| 1 | Single-user mode | System administration |
| 2 | (Multiuser without networking) |
