Ilya Grigoriev ilyagr

Git Compression of Blobs and Packfiles.

Many users of Git are curious about the lack of delta compression at the object (blob) level when commits are first written. This efficiency is saved until the pack file is written. Loose objects are written in compressed, but non-delta format at the time of each commit.

A simple run though of a commit sequence with only the smallest change to the image (in uncompressed TIFF format to amplify the observable behavior) aids the understanding of this deferred and different approach efficiency.

The command sequence:

Create the repo:

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = [email protected]:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

Install

Either copy the aliases from the .gitconfig or run the commands in add-pr-alias.sh

Usage

Easily checkout local copies of pull requests from remotes:

git pr 4 - creates local branch pr/4 from the github upstream(if it exists) or origin remote and checks it out
git pr 4 someremote - creates local branch pr/4 from someremote remote and checks it out

Storing Images and Demos in your Repo

In this quick walkthough you'll learn how to create a separate branch in your repo to house your screenshots and demo gifs for use in your master's readme.

How to

1. Clone a fresh copy of your repo

In order to prevent any loss of work it is best to clone the repo in a separate location to complete this task.

2. Create a new branch

Create a new branch in your repo by using git checkout --orphan assets

Hyperlinks (a.k.a. HTML-like anchors) in terminal emulators

[ Update 2025-03-24: Commenting is disabled permanently. Previous comments are archived at web.archive.org. ]

Most of the terminal emulators auto-detect when a URL appears onscreen and allow to conveniently open them (e.g. via Ctrl+click or Cmd+click, or the right click menu).

It was, however, not possible until now for arbitrary text to point to URLs, just as on webpages.

using rust with rr

rr is a great debugging tool. it records a trace of a program's execution, as well as the results of any syscalls it executes, so that you can "rewind" while you debug, and get deterministic forward and reverse instrumented playback. it works with rust, but by default if you try it out, it could be pretty ugly when you inspect variables. if this bothers you, configure gdb to use a rust pretty-printer

rr is probably in your system's package manager.

usage

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

	function mergeViewHeight(mergeView) {
	function editorHeight(editor) {
	if (!editor) return 0;
	return editor.getScrollInfo().height;
	}
	return Math.max(editorHeight(mergeView.leftOriginal()),
	editorHeight(mergeView.editor()),
	editorHeight(mergeView.rightOriginal()));
	}

	# fshow - git commit browser (enter for show, ctrl-d for diff, ` toggles sort)
	fshow() {
	local out shas sha q k
	while out=$(
	git log --graph --color=always \
	--format="%C(auto)%h%d %s %C(black)%C(bold)%cr" "$@" \|
	fzf --ansi --multi --no-sort --reverse --query="$q" \
	--print-query --expect=ctrl-d --toggle-sort=\`); do
	q=$(head -1 <<< "$out")
	k=$(head -2 <<< "$out" \| tail -1)

	[
	"😁",
	"😂",
	"😃",
	"😄",
	"😅",
	"😆",
	"😉",
	"😊",
	"😋",