Desed: A Debugger for Sed

Desed

Demystify and debug your sed scripts, from comfort of your terminal.

Desed is a command line tool with beautiful TUI that provides users with comfortable interface and practical debugger, used to step through complex sed scripts.

Some of the notable features include:

• Preivew variable values, both of them!
• See how will a substitute command affect pattern space before it runs
• Step through sed script - both forward and backwards!
• Place breakpoints and examine program state
• Hot reload and see what changes as you edit source code
• It's name is a palindrome

Install

From source:

git clone https://github.com/soptikha2/desed
cd desed
cargo install --path .

From cargo:

cargo install desed

Dependencies:

Development: rust , cargo

Runtime: sed (GNU version)

Controls

• Mouse scroll to scroll through source code, click on line to toggle breakpoint
• j , k , g , G , just as in Vim. Prefixing with numbers work too.
• b to toggle breakpoint (prefix with number to toggle breakpoint on target line)
• s to step forward, a to step backwards
• r to run to next breakpoint or end of script, R to do the same but backwards
• l to instantly reload code and continue debugging in the exactly same place as before
• q to quit

FAQ

How does it work?

GNU sed actually provides pretty useful debugging interface, try it yourself with --debug flag. However the interface is not interactive and I wanted something closer to traditional debugger.

Does it really work?

Depends. Sed actually doesn't tell me which line number is it currently executing, so I have to emulate parts of sed to guess that. Which might not be bulletproof. But it certainly worked good enough to debug tetris without issues.

Why sed??

Sed is the perfect programming language, especially for graph problems . It's plain and simple and doesn't clutter your screen with useless identifiers like if , for , while , or int . Furthermore since it doesn't have things like numbers, it's very simple to use.

But why?

I wanted to program in sed but it lacked good tooling up to this point, so I had to do something about it.

Why?

Because it's the standard stream editor for filtering and transforming text. And someone wrote tetris in it!

What is the roadmap for future updates?

I would like to introduce syntax highlighting and add this tools to standard repositories of all major distributions.