The next four chapters cover nvi, elvis, vim, and vile, in that order. Each chapter has the following outline:
Who wrote the editor, and why.
Important command-line arguments.
Online help and other documentation.
Initialization -- what files and environment variables the program reads, and in what order.
Multiwindow editing.
GUI interface(s), if any.
Extended regular expressions.
Improved editing facilities (tag stacks, infinite undo, etc.).
Programming assistance (edit-compile speedup, syntax highlighting).
Interesting features unique to the program.
Where to get the sources, and what operating systems the editor runs on.
All of the distributions are compressed with gzip, GNU zip. If you don't already have it, you can get gzip from ftp://ftp.gnu.org/pub/gnu/gzip-1.2.4.tar. The untar.c program available from the elvis ftp site is a very portable, simple program for unpacking gzip'ed tar files on non-UNIX systems.
Because each of these programs continues to undergo development, we have not attempted an exhaustive treatment of each one's features. Such would quickly become outdated. Instead, we have "hit the highlights," covering the features that you are most likely to need to know about and that are least likely to change as the program evolves. You should supplement this book with each one's online documentation if you need to know how to use every last feature of your editor.