sdomi

for the latest chapter of what's becoming a blog on the most cursed bash you can imagine, let's do some maths together

euclid's algorithm for gcd could be written like this in python:

>>> def gcd(a, b):
...     if b:
...         return gcd(b, a%b)
... return a

context: shells want to leave the seek position at the right offset so external commands can continue reading from the same fd

i saw this somewhat surprising tally of syscalls in bash. let's investigate

one iteration:

unblock all signals

A funky shell thingy that I've never seen before

So you're in posix sh and you want to do the equivalent of this in bash:

foo | tee >(bar) >(baz) >/dev/null

(Suppose that bar and baz don't produce output. Add redirections where needed if that's not the case.)

Advanced Recursive Diffing™

Ever needed to diff two trees of files, while doing some preprocessing on modified files? Well - we've got a solution for you. Or rather... our long friend git has.

Turns out it's perfectly legal to just use git diff --no-index on directories outside of (any) git repository. With that, we can (ab-)use built in git diff per-path/extension preprocessing feature.

Signal on Windows without a smartphone

Requirements

Installation

Using the fs-net libtransistor fork

This guide assumes you are already familliar with setting up RetroArch with libtransistor.

Clone the fs-net branch from https://github.com/davidbuchanan314/libtransistor:

git clone https://github.com/davidbuchanan314/libtransistor --recursive -b fs-net

Build libtransistor as usual.

	sed 'sentence;secede;secede' <<< canter # canter -> cancer -> dancer -> dander
	sed 'severe;serene;secede' <<< cove # cove -> core -> cone -> done

	sed 'septette;settee' <<< Capt # Capt -> Catt -> Ca
	sed 'severe;serene' <<< Iva # Iva -> Ira -> Ina
	sed 'severe;serene' <<< paves # paves -> pares -> panes
	sed 'secrete;settee' <<< critter # critter -> titter -> tier
	sed 'severe;serene' <<< v # v -> r -> n
	sed 'severe;serene' <<< coves # coves -> cores -> cones
	sed 'severe;serene' <<< vapes # vapes -> rapes -> napes

	#!/usr/bin/awk -f

	# This program is a copy of guff, a plot device. https://github.com/silentbicycle/guff
	# My copy here is written in awk instead of C, has no compelling benefit.
	# Public domain. @thingskatedid

	# Run as awk -v x=xyz ... or env variables for stuff?
	# Assumptions: the data is evenly spaced along the x-axis

	# TODO: moving average

	# Use this script to test that your Telegram bot works.
	#
	# Install the dependency
	#
	# $ gem install telegram_bot
	#
	# Run the bot
	#
	# $ ruby bot.rb
	#

	# try catch for bash/mksh/zsh/dash/busybox
	[ "$BASH_VERSION" ] && shopt -s expand_aliases
	alias try='tryblock ()'
	alias throw='return'
	alias catch='if tryblock; then :; else '
	alias end_try='fi'
	alias exceptions:='case $? in x) '
	alias except=';;'
	alias end_exceptions='esac'
	alias always=' '