XXI

The new default.

The most basic text editor with code running, undo-redo, and everything a working text editor needs.

One file of C. No libraries. It just works.

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Get it

git clone https://github.com/SunqdXX/XXI.git
cd XXI
./install.sh

That is it. It builds itself and puts xxi where your terminal can find it.

Even shorter (one line, no cloning):

curl -fsSL https://raw.githubusercontent.com/SunqdXX/XXI/main/install.sh | sh

Want it for everyone on the computer?

sudo ./install.sh

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Use it

xxi notes.txt

If the file is not there, XXI makes a new one for you.

Now just type. That is it.

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The keys

Press this	And it does this
Ctrl-S	Save
Ctrl-W	Quit. It asks first. Press Enter to really quit.
Ctrl-C	Copy
Ctrl-V	Paste
Ctrl-K	Delete the whole line
Ctrl-R	Undo
Ctrl-Y	Redo
Ctrl-X	Select stuff
Ctrl-F	Find
Ctrl-T	Run your code
Alt-C	Copy out of the terminal at the bottom
Alt-V	Paste into the terminal at the bottom

You do not have to remember any of these. They are always listed on the right side of your screen.

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Run your code

1. Open a file, like xxi hello.py
2. Press Ctrl-T
3. It asks "run python3 hello.py?" — press Enter

Your code runs. The output shows up at the bottom. Press Esc to close it.

Press Ctrl-T again to run it again.

While your code runs, the keys go to it. Ctrl-C stops it — always, exactly like a normal terminal. And when you stop it you are left at a shell prompt in that same box, so you can just run something else. You never have to close the terminal to get out of a program.

Want a line of the output? Just drag over it. Letting go of the mouse copies it — no key at all. To paste something in, press Alt-V. Either way the terminal stays yours, you do not have to leave it to copy.

C and C++ get the math library linked for you, so pow and sqrt work without you having to know about -lm.

The box at the bottom is a real terminal, not a picture of one. Your colors come through, so a red compiler error stays red. Long lines wrap instead of falling off the edge. Programs that draw the whole screen work too — you can run vim down there if you like, and when you quit it your output comes back exactly as you left it.

One thing to know: Esc closes the terminal, unless a full-screen program is running — then Esc belongs to that program, the way it should. Press Ctrl-T to step back into the editor first.

It knows how to run Python, C, C++, Rust, Go, JavaScript, Ruby, Lua, Perl, PHP, Java, R, Julia and shell scripts. If it does not know your file, it gives you a normal terminal at the bottom instead.

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Select stuff

Press Ctrl-X. Now drag with your mouse, or use the arrow keys. What you picked lights up. Press Backspace and it is gone.

Just want to copy something? Do not press Ctrl-X. Just drag with your mouse and press Ctrl-C.

What you picked stays lit after you copy it. Press Ctrl-C ten times if you want — you get the same thing every time. Press Esc, click somewhere, or just start typing to let it go.

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Undo

Press Ctrl-R. Press it again. And again. It goes all the way back to when you opened the file.

Went back too far? Ctrl-Y goes forward again.

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Find

Press Ctrl-F and type. Every match lights up. Press Enter to jump to the next one. Press Esc when you are done.

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Good to know

• Click anywhere with your mouse to put the cursor there.
• Your clipboard is the real one. Copy in XXI, paste in your browser.
• If a file is read-only, XXI tells you and refuses to wreck it.
• No colors on your code. That is on purpose.
• Alt-C and Alt-V do the same as Ctrl-Shift-C and Ctrl-Shift-V, for terminals that keep those keys for themselves.

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Copying out of the terminal

Here is a thing about terminals that is worth knowing, because it looks like a bug and is not one. Ctrl-Shift-C never reaches the program you are running. Your terminal — kitty, GNOME Terminal, Konsole, Alacritty, foot, all of them — keeps that key for its own copy and swallows it. And its copy works on its selection, which is empty here, because XXI is reading the mouse itself. So in most terminals Ctrl-Shift-C quietly does nothing in any program like this one.

So XXI does not rely on it:

• Drag and let go. That copies. No key, no setup, works in every terminal.
• Alt-C / Alt-V if you want a key. No terminal claims these.

If you would rather have Ctrl-Shift-C anyway, you have to tell your terminal to hand it over. XXI titles its window XXI: <file>, so you can aim the rule at XXI alone and leave copy and paste alone everywhere else. In kitty that is two lines in kitty.conf:

map --when-focus-on title:^XXI: ctrl+shift+c send_text all \x1b[99;6u
map --when-focus-on title:^XXI: ctrl+shift+v send_text all \x1b[118;6u

Reload with Ctrl-Shift-F5 and restart XXI. Other terminals have their own way of saying the same thing; the escape codes to send are the kitty keyboard protocol's, which XXI asks for on startup.

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That is everything

Really. There is nothing else to learn.