ed: Line-Oriented Text Editor

Overview

ed is a powerful yet concise editor specialized for editing text files line by line. In addition to interactive mode, it can be used non-interactively in scripts, making it suitable for automated text processing.

Key Features

Line-oriented editing: Works one line at a time
Script-friendly: Suitable for non-interactive use
Extremely lightweight: Uses minimal resources
POSIX standard: Included by default on most Unix/Linux systems

Key Options

ed has few command-line options; most functionality is performed through editor internal commands.

Behavior Control

Generated command:

Try combining the commands.

Description:

`ed` Executes the command.

Combine the above options to virtually execute commands with AI.

Usage Examples

ed can be used interactively or via input redirection in scripts.

Create a new file and add text

ed newfile.txt
a
Hello, ed!
This is a test line.
.
w
q

Open a new file, add text, then save and quit.

Open an existing file and view its content

ed existing_file.txt
1,$p
q

Open an existing file, print all lines, then quit.

Substitute specific text (non-interactive)

echo '1,$s/old_text/new_text/g
w
q' | ed -s my_document.txt

Replace all occurrences of 'old_text' with 'new_text' in the file and save. Suppress output with the -s option.

Append content to the end of a file (non-interactive)

echo '$a
New line added at the end.
.
w
q' | ed -s my_document.txt

Add a new line to the end of the file and save.

Tips & Notes

ed's usage is very different from other modern editors, so understanding a few key concepts is important.

Key Concepts for Using ed

Command Mode and Input Mode: ed is in command mode by default. You enter input mode with commands like a (append), i (insert), and c (change). In input mode, typing . (dot) on a line by itself returns you to command mode.
Addressing: Commands can be applied to specific lines (e.g., 1 for the first line, $ for the last line, . for the current line) or line ranges (e.g., 1,$ for the entire file).
Saving and Quitting: Use the w command to save changes and the q command to exit the editor. Combinations like wq are not supported. Q quits without saving changes.
Checking Current Line: Typing . prints the content of the current line, and the = command prints the current line number.
Using Regular Expressions: Powerful regular expressions can be used with the s (substitute) command to find and replace text.