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Love it, thanks for posting!
Incredibly goofy, I like it. Especially the demo gifs on the page. Wonder how long until I see it be the default output for a CLI I'm using. Got surprised to see someone using lolcat in the wild before.
Great work, this will make a lovely splash screen for my tty-only machine.
In a similar vein in Emacs: M-x zone

Every time you run it, it triggers a random screen saver effect. Fun when it's on a timer and triggers so your work colleagues wonder wth is going on.

I just get a blank emacs buffer when I run that.
Even if you run it in a buffer that is already full with text? Zone mode only really works if you have text in the buffer.
ohhhhhhhhh
Or neovim … cellular automaton
Emacs has game of life also. M-x life.
and animate.el by mister Stallman, see it in action with M-x animate-birthday-present
good one! The editor macros collection never ceases to amaze even after years of working daily in it.
> M-x zone

Available in the menu: Tools → Games → Zone Out

Next time someone donks Python for being incapable of building decent CLI tools, I'll burn their terminal using TTE.

I know Go has the crown for creating TUI apps, but Python isn't that awful. If the app doesn't need concurrency (like a terminal file manager [0] does), then Python is fine.

[0]: Yazzi (Rust) eats Ranger's (Python) lunch and dinner combined.

I freaking love this library! It reminds me of a time that I don't even know happened when computers seemed like a scifi possibility come true. So happy to see it on the front page.

One of the coolest things is not just the ability to pipe cat outputs into it, but that it doubles up as a python library- next time you're making a throw away CLI with print outs and prompts, why not make it insanely jazzy?

It's fun for silly stuff, but I've definitely been on enough slow links that I wouldn't put it in a serious tool.

EDIT: Don't get me wrong, I think it's really cool, but I wouldn't use it as a universal hammer.

On the contrary, I am currently scaffolding out the template projects for a new system at $DAYJOB and I'm seriously considering putting it in the CLI tool template.

On the one hand, these tools are going to be used for Serious Business™ but on the other hand... I owe it to 14 year old me. I'll probably add something to allow disabling it with a flag file that can be created with the tool or manually. ¯\_(ツ)_/¯

I love this kind of things the first time I see them but I would hate it in a tool used everyday
./myfancytool -disablefx

./myfancytool -showfx

Or have an "on first run only" configuration that disables it for subsequent usage of the tool ¯\_(ツ)_/¯

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I agree, a serious tool should be taking into account the length of the output delay and reducing effects to match the conditions. But you can still do some of it, sometimes.
Someone will add this to their javascript framework cli
This is great, thanks!

My favorite is Beams (the one at the very top of the page), reminds me of MGS1 “game over” screen animation a lot.

This is cool! we can utilize the 'Burn' or 'ErrorCorrect' effects to highlight warnings or errors in logs dynamically, ensuring critical issues stand out in ongoing terminal output.
No. No, you don't. No one investigating log files wants animations playing in them.
Haha..I get where you're coming from. However, tool that show reports and outputs, that are CLI-first, can get a lot of help in improving the developer experience. Honestly, I was looking for something like this for my tool!
I'm glad to see we all take the same approach to these sorts of things ^_^

  self.move_cursor_to_top()
  sys.stdout.write(output_string)
  sys.stdout.flush()
Would there be a more canonical way do do this?
Back in the day (around 1990) I implemented a gif-like effect for terminals, which happened to be old monochrome hardware terminals on slow (9600?) RS-232 ports, attached to a venerable PDP-11.

It took several text files with ASCII "pictures" (character data only, no control codes, 80x24) as animation frames, and calculated simple per-line "diffs". Then it generated a sequence of cursor movements to only update the affected areas, skipping large parts of the picture.

That made it much faster than the naive overwriting the whole screenfuls from top, with a visible delay between parts of the screen. My version was able to run "simultaneous" small animations quickly at distant parts of the screen, because they took very few bytes to navigate to and update.

   *
     *. 
  * o/
  -/M 
   _H_
E.g. a "juggler" like this could juggle quickly, inside a mostly stationary "circus", with "flags" waving high above on top of it.

With current terminals giving you 60fps in true-color mode, it makes little sense, of course.

Not redrawing the parts of the screen that don't need to be redrawn. There's going to be a tradeoff between the amount of works the terminal has to do parsing the input stream, the amount of work the terminal has to do to redraw/update its own buffer, and the amount of work necessary in the program to compute the necessary move commands.

IIRC, ncurses does this under the hood.

To be fair, the effects shown here update such a significant part of the screen that tracking the diffs might be bigger overhead than a full-screen refresh
I think the canonical way would be to ship this in some sort of hard-to-uninstall snap or flatpack package.
Flatpak is actually pretty nice and not affiliated with Canonical. No forced automatic updates with a daemon and easy to manage.
This is amazing! Please never ever use it in production.
Idk I wouldn’t mind one or two of these as loading screens or something.
As a developer-only tool, I’m sure most of my coworkers would love the attention to details.
As a product engineer, I'd love the attention to detail much more when placed toward changes that improve my ability to sustain velocity, than when toward changes that actively cut against that.
What CLI tools have a slow enough boot to require a loading screen? I'm sure there are some but...

The only one that comes to mine for me is FileBot[0] - and if the loading screen made it take ANY additional time, I'd be annoyed.

[0] https://www.filebot.net/

Deployment scripts are what come to mind for me. I wouldn’t mind a cool loading screen that highlighted problem nodes in the burning font or something when I deploy to dev / test / hell, maybe even prod.
Anything that downloads from somewhere, eg rsync, wget, package managers, etc.

Anything that compresses or decompresses archives, like gzip/gunzip, tar, etc.

Anything that performs longer running recursive disk activities, like du, find, etc

I’m sure there are plenty more scenarios I haven’t thought of. Though to be clear, I definitely don’t want to see this as a default enabled option in any of these.

If things are working well, they are automated and I rarely see the real time output.

If I’m looking at real time output, it’s because I’m doing something manually because something isn’t working the way it’s supposed to, and I’m in no mood for anything that doesn’t help me understand and address the issue.

This work is impressive. I love it. For some reason I really like “printer.” I’d be all about it for games or toys. But too many tools for real work try to do cute Unicode things or fancy colors or animations. I don’t need it on anything I will ever have to develop or troubleshoot, personally. After the first lengthy wait for a broken container to come up, I’m well over the colorful attitude.

I deliberately mentioned stuff that people are likely to manually run on local and healthy systems. But yeah, I agree with you that the novelty of this stuff wares off quickly.

An example of this done well would be ‘pacman’ package manager where an Easter egg can be enabled to turn the progress bar into a little Pac-Man gobbling pills. It’s not there by default, but it can be enabled if you know how.

Personally, I’m in the same camp as yourself where I’d prefer our tools didn’t have all this cutesy stuff. But people like us seem to be a dying breed.

Not for booting but for processing (downloading files, processing a directory, waiting for an api, etc)
It could be cool for GUI programs, when run from a terminal, to show a terminal loading screen parallel to the gui loading screen. Totally unnecessary, but cool.
No. I still sometimes need to use a TTY over MOSH over a satellite connection.

No.

In the old days, some software would actually check the terminal's baud rate (which you can see with 'stty') and behave differently on slow links. For example, vi would restrict itself to fewer lines of the screen so that drawing a new page didn't take as long.

Although I don't know if much software does it, that should still be possible to do it, so these animations could theoretically be auto-disabled on slow links. (And you could manually override the baud rate in your mosh terminal if necessary since it doesn't really have any other effect in a virtual terminal, not like when using an actual serial port, I mean.)

It shouldn't matter, should it? Mosh keeps the state and only sends the differences. You would miss most of the animations, and there would be the overhead of sending the colouring escape codes (a few percent extra), but other than that, it wouldn't be any slower than an unanimated version that I can see.
Why not?
Imagine that the CLI tool you use most often every day - a compiler, a package manager, like that - adds animations like these in common operations. Now you have to wait for the animation to finish before you can continue your work. How do you feel about that?
Of course it would be obnoxious.

As an "about" screen, or in a opt-in funny theme why not !

The idea that anyone would use this during "common operations" is laughable, but as one offs during specific operations, maybe.
> The idea that anyone would use this during "common operations" is laughable

It's been a while since I dared assume anything at all was so obviously absurd that no one could ever think to do it - not least since significant portions of my career to date have consisted of cleaning up after people who had.

?? Why would I imagine that? What does this have to do with using animations in production? What you are saying is "how would you feel about using animations in inappropriate places?"
> What does this have to do with using animations in production? What you are saying is "how would you feel about using animations in inappropriate places?"

Production will always be an inappropriate place. QED.

I actually did some color animations to status bar of build tool I created while ago. In my opinion this distracted enough to make build feel faster

Edit: popular example of less invasive animations would be new docker cli, (pulling, buildx build)

Yeah. Animations covering time that'd be spent either way I see no problem with, so long as it's obvious the time would be spent either way. Animations that waste my time, not so much.

Better than either, of course, would be effort spent on speeding up the build in the first place. I realize that's less fun, though.

In general, the critical development path is not a place to thoughtlessly add friction.

Also, I don't want to even imagine how it would look on a SSH connection.
It’s trivial to add in a keypress that short circuits the animation. God, this website is full of the grumpiest people on the planet.
It's not grumpy to prefer function over form in a tool. People optimize for different things. GP's comment is reasonable; they're optimizing for something different than you.
Those of us who live in the terminal do it because it's the fastest, most convenient option, not because it's pretty or to appear 1337. Animations like these get in the way. Cool project, but I would never use it.
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Prod should be as robust and straightforward as possible; no distractions, no noise, no extra overhead. This is neat, but not useful, and it adds distractions and delays.
These are beautiful.

What I'd really like to see is this supported in the terminal emulator itself as an idle mode, i.e. don't run this in the buffer directly, but rather as a second buffer. This could function like a "screen saver". Once you interact, your primary terminal would be fully restored.

s/fully/gradually/

I’d love some of these effects to fade in/out within live terminal sessions.

As long as readability wasn’t affected though.
I was thinking about how fun it would be to add this my Python CLI [0] I made for launching Fedora CoreOS locally with QEMU for testing ignition, but with a flag that is turned off by default. Using the burn effect in TTE when launching a VM with my CLI would be so cool.

This instantly reminded me about Ansible and how it annoyed me that ANSIBLE_NOCOWS had to be enabled to disable the default output of Ansible with cowsay [1].

[0]: https://github.com/quickvm/bupy

[1]: https://github.com/ansible/ansible/issues/10530

On a further tangent, that reminds me of two of my favorite things to install on a Linux system, ponysay and ascii-pony/systempony. I set each of my systems to a different character to show on bash logins with systempony (WSL instances included)

https://github.com/erkin/ponysay

https://blog.yjl.im/2016/01/ascii-pony-systempony-screenshot...

A while back I install ponysay on one of my servers, and put fortune | ponysay in the .bashrc, so I get a quip from a random mlp pony whenever I log in. Brightens my day a little
Hot damn, I have to respect the author for shutting down any attempt to make him give in to the pressure.

All these serious enterprise people worried about their cows, but then they do install ‘cowsay’ on their systems xD

The people complaining probably don't have the authority to remove it from the base image they're forced to use, unfortunately.
How serious can your enterprise be if they install cowsay on their base image?
How serious it is, and how seriously the people who make decisions take it, are if not strictly orthogonal then certainly not guaranteed to closely correlate.
it's not a matter of seriousness, if you install all the packages, cowsay gets picked up in the mix
Please use this to reboot Trade Wars 2002.
Oddly enough, I was just thinking about that sort of thing...
BBS Doors! I knew this reminded me of something (in a good way).
Who wants to actually read text anyway.
I propose that developers are allowed to use it in production... so long as they do all the development work on a 9600 baud dialup with a VT102.
A few years ago, a submarine cable was knocked out, between our startup's MVP servers in Singapore AWS, and our networked factory stations in Asia.

In lieu of the submarine cable, something closer to a wet string was being routed over. It had such high latency and packet loss, that a watchdog timer I'd implemented on the stations was timing out.

Fortunately, the remote access we'd built into our stations (SSH and OpenVPN) still worked, albeit at slow speeds, like a 300 baud dialup, and crazy-high latency.

Having occasionally dealt with performance a bit like that as a kid, and knowing my way around Linux, it was like "I've been training my whole life for this moment."

So I just flexed the old command-line-and-editor-when-you-feel-every-byte-transmitted skill, and got the stations working, before the factory even knew about the submarine cable, saving our infinite-9s uptime.

It was nothing compared to what NASA does, but terminal animation effects would've ended both of our missions.

I think my first action in a situation like that would be an attempt to install mosh from a local mirror.
That needs a binary to run on the remote host for protocol support, doesn't it? I wonder how long that'd take to get transferred and running, over as slow a link as it sounds like this was.
Since you can reach the host, presumably it has some kind of access to system updates / packages. In that case, ideally you paste a command like "sudo apt update && sudo apt install -y mosh\n" or something. You can even paste the newline at the same time and save a round-trip.
"from a local mirror" does not involve transferring the binary over the slow link.
It isn't perfectly clear even in the detailed description whether any other link was available, but I tend to suspect that if anything faster had been, then it would have been used in preference to the one that actually was.
It's a cable going between entire countries that got cut. Anything inside the country should still be full speed.

There is no link that could be used in preference. Any repo that the factory stations could access would be unusable by Singapore AWS. And any repo that Singapore AWS could access would be unusable by the factory stations. But the two ends of the link don't have to use the same repo.

How exactly did you get the stations working? Be specific.
"Be specific" sounds like a high-stakes interview, so I'd better answer. :)

* SITUATION: Factory reports MVP factory stations for pilot customer "not turning on" for the day, reason unknown.

* TASK: Get stations up in time for production line, so startup doesn't go out of business.

* ACTION: Determined cause was unexplained networking problem outside our control, and that was triggering some startup time checks. But that the stations were resilient enough that I could carefully edit the code on the stations to relax some timeouts, and enough packets were getting through that we might be able to operate anyway. After that worked for one station, carefully changed the remaining ones.

* RESULT: Factory stations worked for that production day, and our startup was therefore still in business. We were later advised of the submarine cable failure, and the factory acknowledged connectivity problems. Our internal post mortem discussions included why the newer boot code hadn't been installed, and revisiting backup connectivity options. From there, thanks to various early-startup engineering magic, and an exciting mix of good and bad luck, we eventually finished a year contract in a high-quality brand's factory production line successfully.

No technical wizardry in the immediate story, but a lot of various smart things we'd done proactively (including triaging what we did and didn't spend precious overextended time on), plus some luck (and of course the fact that some Internet infrastructure heroes' work had them routing any packets at all)... all came together... and got us through a freak failure of a submarine cable we'd never heard of, which could've ended our startup right there.

(Details on Action, IIRC: Assumed command of the incident, and activated Astronaut Mode manner. Attempted to remote access, and found network very poor. Alerted factory of network problem in their connectivity to AWS Singapore, but they initially thought there was no problem. Could tell there was some very spotty connectivity problems (probably including using `mtr-tiny`), so focused troubleshooting stations on that assumption. Realized how the station would behave in this situation, and that the boot-ish checks for various network connectivity were probably timing out. Or, less likely, there could be a bug in handling the exceptional situation. Investigating, very slowly due to poor Internet, found that the stations didn't have the current version of the boot code, which would've reported diagnostics better on the station display, so factory personnel might see it and tell us. Using `vi`, made careful, minimal changes to the timeouts directly on one station, in the old version of the the code on there (in either Python or Bash; I forget). Restarted station, and it worked. Carefully did the same to the other stations. Everything worked, and other parts of the station software had been done smart enough that they could cope with the production day's demands. Despite the poor connectivity, and the need to do network requests for each production item that passed through the station, before it could move on.)

I love the five point order-esque style, warms my military heart
Is it me reading it wrong or are you using two "startup" meanings in sentences very close to each other?
I realized that, and so tried to say "boot" for one of the term senses, but missed an occurrence, which might've made it even more confusing.
I did something similar once when something broke while I was on a plane. The plane wifi was blocking ssh (I HATE when they do this) so I opened up an existing digital ocean instance, sshed into my home computer from it via the web interface, then uploaded some large files from the home computer and did a kubectl apply. The latency was insane but luckily the file upload was fast since my home connection is fast.

It was fun to think about the path each packet was taking - from my laptop to the plane router, to a satellite, back to a digital ocean computer in the UK, to my home computer in NJ, and back. It wasn’t as bad when you think about the magic there.

Smart, and not something someone would realize if they'd been too insulated from how things work.

Regarding planes/cafes/guest/etc. WiFi, I now usually put any "emergency remote plumbing access" on port 443 (though usually not HTTPS), to reduce the likelihood of some random non-SPI ruleset blocking us in an emergency.

You can also proxy 443 out with ssh.
Or setup a web ssh client and actually run HTTPS over port 443.
I think that by 2050, 443 will be the only port used by applications that require a non local connection, because the chance that some participant in the network has blocked any other port is simply too high.
Future generations will ask - “why does every packet header have this 2 byte reserved field with a fixed value of 01BB?”
It would truly have been elite if you'd have to pull out Kermit and use that.

"line is ~300 baud but only transmitting 7 bit but we need to send this critical file.. which is in EBCDIC!"

I'm very glad that TCP is so robust.

I'd take a solid 300 baud connection over a spotty cellular connection during most emergencies.

Having worked and played on flaky high-latency and low-throughput networks much of my life, I mostly visualize things in my head—as you likely mean by 'command-line-and-editor-when-you-feel-every-byte-transmitted'. Open a connection and queue your commands; wait for output. It works if you don't make any typos.

Preferably, when the connection is too slow or flaky (bad cellular), I make a local script and echo the script to be executed remotely to a file on the remote server, and then execute it with nohup - with the input to create the script and execute it coming from a pre-made file on my local machine redirected to SSH.

Bad cellular often works in bursts, in my experience. Also, redirect output to a file if needed.

This works nicely in situations where your connection may drop frequently for periods exceeding timeouts. On that note, keep ssh timeouts high. With really spotty cellular you might have the network drop for 5-15 minutes between reliable transmissions. SSH connections can stay alive nearly indefinitely if the timeouts allow for it and IP address don't change.

> local script [...] nohup [...] redirect output to a file

  mosh hostname -- screen -S philsnow
I don't think I've had to use this over a truly terrible connection, but mosh worked a treat a ~decade ago while tunneling through DNS from a cruise ship that charged exorbitant rates for wifi while underway, but which allowed unlimited DNS traffic.

> It works if you don't make any typos

mosh helps a bit with that too: you get local predictive echo of your keystrokes and you can't "recall" keystrokes but you can queue up backspaces to cover up your typos. Doesn't help where a single typo-ed keystroke is a hotkey that does something you didn't want, though.

Mosh looks handy. Thanks for sharing!
Nothing like typing in an ssh prompt and each time you press a button on the keyboard you have to wait a few seconds for the char to appear on the screen, because it has to go to the server and back first... that't the true "blind typing" :)))
TERM=dumb seems like a good idea in a situation like that.
I actually am getting a VT320 soon that I hope to be able to use for my terminal at work. I'll run these over it if I remember.
It won't work. It assumes 24-bit colour support, even if you have `TERM=vt320` or something else without it.
Damn, just a programming oversight? You don't need colors to get a lot of these effects. Maybe I'll fork it.
There’s a —no-color argument.

Example: ls | tte —no-color slide

I’ll add environment variable checks to the todo list.

It can work we just need brave soul to make it client side.
Agreed. It's not nearly as battle-tested as key operations tooling like `sl` and `gti`.
Uh, we accidentally shipped it as our fintech startup screen.
Please do use it in demoscene productions. We need more textmode demos.
It would be great for the startup screens of terminal games.
Challenge accepted.
It'd be good if it recognised https://no-color.org/ and just didn't do anything. Or maybe replaced with <cool effect removed here>

Maybe it does, I didn't check.

It does have a --no-color flag.

That being said, there are some environment variables that could be referenced. I'll add this one to the list for a future update.

What if I want colors, but not animations?
But if you do, include emoji animations
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> ./myfancytool -nofx -doingbusiness -pwn "the_ops"
The effects on this project is incredible, thanks for building this!
These effects remind me of some of the first programming I ever did: animated ASCII art for local BBS’s.

I remember dumping an entire day into something resembling Spider-Man. Was very exciting when a sysop put my work into their login sequence.

Reminds me of the drip.com TSR program that I put on some of the school computers circa 1990.
Yeah in 1991 our college lab's MSDOS PC's were unsecured (unsecurable!?), so our prof quickly learned to regret teaching us how to write TSR's in ASM.
Ours had PS-2s on a token ring network with a TUI to get to the word processor etc but it also had a “drop down to DOS” option that the teachers didn’t know about.
I also got in trouble for playing Leisure Suit Larry in 6th grade computer class.
LOL brute-forced the "adult knowledge" questions at startup, huh?
oh how fun this must have been to implement these effects. absolutely love it!
So much energy going into the command line/terminal at the moment. Reminds me a lot of BBS art of my youth. Where are my TheDraw crew?
These effects would pair really well with an old school bbs/mud simulation.
Retro-cyberpunk aesthetic.

Hacking game?

Or a non-simulated BBS or MUD.
Kind of tools I wish I had a use case for.
There's a bit of lag on my VT420.
Even at 19200 baud?
Code looks very clean, congrats. I wish for selfish reasons this was written in Go, so I could stuff the binary somewhere easily :)
I could see this idea being used in a lot of the charm.sh products.
All gorgeous, but I'd like to see more quick/simple ones like 'Expand' because the slower ones would probably become tedious real quick after the initial novelty wears off.
Dev here: I agree, it's actually a line item in my todo list. That being said, many of them can be made to be very quick via command line arguments without losing the spirit of the effect.
That's a delightful thing you've made.

Have you added a command-line switch for the direction of gravity?

Some of the animations (eg Pour), could fall up the screen instead of down it. That way, the user can start reading the text immediately.

ls -latr | tte pour --pour-direction up

I have not implemented gravity, haha. I have actually worked on a custom terminal game engine in the past and realized with TTE I am very small amount of scope creep away from landing in that territory again. I promised myself I will not implement physics or collision. Keeping it simple. That being said, as with the example pour syntax above, all of the effects have a ton of config options to allow for most obvious variations.

I thought there might be one :)

3d... 3d... 3d... you know you want to.

Chalk maintainer here. These are incredible. Some of the best I've ever seen. Kudos.