Text Editors

Introduction

• How to create and edit files using the available Linux text editors.
• nano, a simple text-based editor.
• gedit, a simple graphical editor.
• vi and emacs, two advanced editors with both text-based and graphical interfaces.

Basic Editors: nano and gedit

nano

• nano is easy to use, and requires very little effort to learn.

• To open a file, type nano <filename> and press Enter. If the file does not exist, it will be created.

• nano provides a two line shortcut bar at the bottom of the screen that lists the available commands. Some of these commands are:

  Command	Usage
  CTRL-G	Display the help screen.
  CTRL-O	Write to a file.
  CTRL-X	Exit a file.
  CTRL-R	Insert contents from another file to the current buffer.
  CTRL-C	Show cursor position.

gedit

• can only be run within a Graphical Desktop environment. It is visually quite similar to the Notepad text editor in Windows
• To open a new file find the program in your desktop’s menu system, or from the command line type gedit <filename>. If the file does not exist, it will be created.

More Advanced Editors: vi and emacs

vi (VIM Improved)

Modes in vi

Mode	Feature
Command	- By default, vi starts in Command mode. Each key is an editor command. Keyboard strokes are interpreted as commands that can modify file contents.
Insert	- Type i to switch to Insert mode from Command mode. Insert mode is used to enter (insert) text into a file. Insert mode is indicated by an “? INSERT ?” indicator at the bottom of the screen. Press Esc to exit Insert mode and return to Command mode.
Line	- Type : to switch to the Line mode from Command mode. Each key is an external command, including operations such as writing the file contents to disk or exiting. Press Esc to exit Line mode and return to Command mode.

[[vimtutor]]

Most important vi commands

Command	Usage
vi myfile	Start the editor and edit myfile
vi -r myfile	Start and edit myfile in recovery mode from a system crash
:r file2	Read in file2 and insert at current position
:w	Write to the file
:w myfile	Write out to myfile
:w! file2	Overwrite file2
:x or :wq	Exit and write out modified file
:q	Quit
:q!	Quit even though modifications have not been saved

Searching for Text in vi

**ENTER** key should be pressed after typing the search pattern.

Command	Usage
/pattern	Search forward for pattern
?pattern	Search backward for pattern

most important keystrokes used when searching for text in vi.

Key	Usage
n	Move to next occurrence of search pattern
N	Move to previous occurrence of search pattern

Changing Cursor Position

Key	Usage
arrow keys	To move up, down, left and right
j or <ret>	To move one line down
k	To move one line up
h or Backspace	To move one character left
l or Space	To move one character right
0	To move to beginning of line
$	To move to end of line
w	To move to beginning of next word
:0 or 1G	To move to beginning of file
:n or nG	To move to line n
:$ or G	To move to last line in file
CTRL-F or Page Down	To move forward one page
CTRL-B or Page Up	To move backward one page
^l	To refresh and center screen

Using External Commands in vi

• Typing **sh** command opens an external command shell. When you exit the shell, you will resume your editing session.
• Typing **!** executes a command from within vi. The command follows the exclamation point.
• This technique is best suited for non-interactive commands, such as : **! wc %**. Typing this will run the **wc** (word count) command on the file; the character % represents the file currently being edited.

Emacs

• Rather than having different modes for command and insert, like vi, emacs  uses the **CTRL** and Meta (**Alt** or **Esc**) keys for special commands.

Working with emacs

Key	Usage
emacs myfile	Start emacs and edit myfile
CTRL-x i	Insert prompted for file at current position
CTRL-x s	Save all files
CTRL-x CTRL-w	Write to the file giving a new name when prompted
CTRL-x CTRL-s	Saves the current file
CTRL-x CTRL-c	Exit after being prompted to save any modified files