Web site: gnu.org/software/ed/ed.html
Subcategory: Text Editors
Platform: Linux, UNIX-like, BSD, OS X, Windows
License: GNU GPL
First release: 1969
ed – a line-oriented text editor. It is used to create, display, modify and otherwise manipulate text files, both interactively and via shell scripts. A restricted version of ed, red, can only edit files in the current directory and cannot execute shell commands. Ed is the ‘standard’ text editor in the sense that it is the original editor for Unix, and thus widely available.
The ed utility is a line-oriented text editor that uses two modes: command mode and input mode. In command mode the input characters shall be interpreted as commands, and in input mode they shall be interpreted as text.
The ed utility shall conform to XBD Utility Syntax Guidelines, except for the unspecified usage of ‘-‘.
The following options shall be supported:
-p Use string as the prompt string when in command mode. By default, there shall be no prompt string.
-s Suppress the writing of byte counts by e, E, r, and w commands and of the ‘!’ prompt after a !command.