Vim

Vim (Vi improved) is a text editor based on the text editor. It can be used from the command-line or as a standalone application with a graphical user interface.

Vim command-line
If X Window System support is not needed, install :

Vim GUI
To install Vim with both the ncurses-based interface as well as the graphical interface (for the X Window System - ), install :

There is also an experimental Qt interface called which can also be installed.

Extensions
The category app-vim provides a lot of additional syntax definitions, plugins and other Vim related stuff.

Use emerge or eix to get an overview of available packages in the app-vim category:

Configuration
Vim can be configured on a per-user basis or through a system-wide configuration file.

The system wide settings are set in whereas the user-specific configuration is located inside the user's home directory at.

Getting started
Vim has a built-in tutorial which should require around 30 min to go through. Start it using the vimtutor command:

Using Vim like ex or ed from the command line
It is possible to use Vim for one-liners — commands that can be used in scripts or on the command line to make changes in an unattended manner.

For instance, the following command adds  to the beginning of each line in the  file:

What happens is that Vim interprets the passed on commands (through the  option). The first command is Vim's substitution command (which is very similar to sed's), the second one is Vim's instruction to save and exit the editor.

Change file encoding
To change the file encoding of a file to UTF-8, use the following command (in Vim command mode):

As shown in the previous trick, it is possible to do this from the command line as well:

External resources

 * Vim Documentation Includes Manuals (aka ":help" and Free VIM OPL Book), FAQS, HOWTO's, Tutorials, in HTML, PDF, PS formats.
 * VIM Scripts/Plugins
 * Learning the vi and Vim Editors, 7th Edition O'Reilly  Print ISBN: 978-0-596-52983-3, Ebook ISBN: 978-0-596-15935-1