Introduction

Legend has it that with 3 weeks to kill, Ken Thompson created ed—pronounced “ee dee”—text editor, compiler, and Unix kernel. Wow—talk about productive! Even though ed is old, learning ed is fun and lets you keep the full context of your editing session in your terminal window.

Getting started with ed

You can run ed in your terminal.

To get started, fire up your favorite terminal.
Launch ed.
Begin editing.
```
a
```
Type some text.
```
hello world
```
Exit edit mode back into command mode (with the lone period).
```
.
```
Print the current line.
```
p
```
Write your change.
```
w hello.txt
```
Quit.
```
q
```

Discussion

Consider the earlier editing session:

$ ed
a
hello world
.
p
hello world
w hello.txt
12
q
$

Consider the difference between an editing session with a full screen editor:

$ vim hello.txt
$

With the ed editor, you keep the full history of your editing session in your terminal window.

meta: build steps:

pandoc -f markdown -t html5 -o "2025-02-05 ed.html" "2025-02-05 ed.md"
scp "2025-02-05 ed.html" maxbigras.com:blog

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