TIL

TIL.md

Linux list all procs with command args

ps -ef

Github url shortner

$ curl -i https://git.io 
    -F "url=https://github.com/smusamashah" 
    -F "code=smusamashah"
HTTP/1.1 201 Created
Location: https://git.io/smusamashah

-F is for form data. Same can be done with postman. Send a post request, put formdata in body.

Git

List and apply stash

git stash list
git stash apply <n>
git stash pop <n> # apply and remove from stash

JavaScript

setTimeout(cb, ms)

is unreliable and expensive call. Does not complete on exact given time. If used in a loop, will slow down

Off-Screen rendering improves performance

It improves rendering performance A LOT. On-Screen canvas should only be updated with whatever is there in off-screen canvas.

var ctx_onscreen = document.getElementById("cvs").getContext("2d");
var offscreen_canvas = new OffscreenCanvas(100, 100);
var ctx_offscreen = offscreen_canvas.getContext('2d');

// render everything with this ctx_offscreen

// keep updating the on-screen canvas
function renderLoop() {
    ctx_onscreen.drawImage(ctx_offscreen.canvas, 0, 0);
    requestAnimationFrame(renderLoop);
}
renderLoop();

Export canvas animation to gif or webm

https://github.com/spite/ccapture.js/

or follow this https://webrtc.github.io/samples/src/content/capture/canvas-record/ its creates a webm video file from canvas without performance hit. you can embed this video or convert it to gif later

Play video from canvas as a source

make video tag like <video playsinline autoplay></video> and

var canvas = document.querySelector('canvas');
var video = document.querySelector('video');
var stream = canvas.captureStream();
video.srcObject = stream;

Jenkins

To use Java .jar libraries in groovy, place the jar files in /usr/lib/jvm/java-1.8-openjdk/jre/lib/ext/. Then you can use import mylib.*.

Jupyter Notebook

To install a module in Jupyter Notebook for Python, use !pip install (with an exclamation mark) like below

!pip install sklearn