red is a line-oriented text editor, based on the popular ed utility. It has two modes: command mode and input mode. In command mode the input characters are interpreted as commands, and in input mode they are interpreted as text.
Some of the history of ed is discussed in the article "Where Vim Came From".
cargo install --git https://github.com/badboy/red
$ red file.txt
a
Hello World!
.
w
13
1,$p
Hello World!
q
(.,.)p - Print the addressed lines to standard output.(.,.)n - Print the addressed lines to standard output, preceding each line by its line number and a <tab>.(.,.)d - Delete the addressed lines from the buffer.(.,.)w [file] - Write the addressed lines to the named file. The pathname is remembered for following writes.(.)a - Append text after the addressed line. End text input with a single . in a line.(.)i - Insert text before the addressed line. End text input with a single . in a line.h - Write a short message to standard output that explains the reason for the most recent ?./ - Addressing lines by search.(.,.)g/RE/command - Global regular expression search.'x - Marking lines with a name.(.)r [file] - Read contents of another file and insert into the buffer.e [file] - Delete the entire contents of the buffer and read the specified file into the buffer.(.,.)c - Delete the addressed line, then accept input text to replace these lines.MIT. See LICENSE.
This file was written with red.