RichardBarrell’s gists

RichardBarrell / delete-directories-containing-only-index-html.sh

Created August 17, 2017 20:26

for https://twitter.com/bitfield/status/897823122723921921

-# find directories which contain only one entry called "index.html" and delete them
-# this doesn't enforce that the found "index.html" is a file rather than a directory, symlink, socket, device node, etc
-find . -depth -print0 | \
- awk 'BEGIN{RS="\0";ORS="\0";} match($0, /^(.*)[/]([^/]+)$/, A) {prevDir=dir; dir=A[1]; if ((prevDir == $0) && couldDelete) { print($0); } if (prevDir != dir) { couldDelete = 1; } if (A[2] != "index.html") { couldDelete = 0; } }' | \
- xargs -0 rm -r

RichardBarrell / size_t_minus_one.c

Last active February 4, 2017 04:14

Demonstrating that converting an int containing -1 to size_t does the right thing even where sizeof(int) != sizeof(size_t)

RichardBarrell / pick_csv.py

Created October 2, 2016 23:41

	import csv
	import sys

	try:
	column_indexes = list(map(int, sys.argv[1:]))
	except ValueError:
	sys.stderr.write("Usage: python pick_csv.py 0 1 2...\n")
	sys.exit(1)

	if len(column_indexes) == 0:

RichardBarrell / to_lines.py

Last active February 16, 2016 11:25

	from StringIO import StringIO
	from hypothesis import given
	from hypothesis.strategies import lists, binary


	def to_lines(f, _block_size=32<<10):
	"""file.__iter__ but in python and ought to be slower

	>>> list(to_lines(StringIO("foo\\nbar\\nbaz\\n"), _block_size=2))
	['foo\\n', 'bar\\n', 'baz\\n']

RichardBarrell / Collatz.hs

Created December 15, 2015 21:49

	{-# LANGUAGE BangPatterns #-}
	module Collatz where

	-- thing I want to know: what's the smallest (n) such that a naive C
	-- implementation of "iterate the Collatz function until I get to 1" with
	-- fixed-size integers will encounter an integer overflow
	-- the below is terrible and contains multiple implementations because I kept
	-- trying to make it go faster.

	import Data.Word

RichardBarrell / PrimeLastDigit.hs

Created September 18, 2015 16:11

looks like a roughly even split between 1,3,7,9 up to the millionth prime. I got bored waiting for 10 million to finish.

	module PrimeLastDigit where

	-- compile with:
	-- ghc --make PrimeLastDigit.hs -O2 -main-is PrimeLastDigit.main

	import Data.List (foldl')

	primes :: [Integer]
	primes = 2 : [ c \| c <- [3,5..], all (\p -> c `mod` p > 0) (takeWhile (\p -> p*p <= c) primes) ]

RichardBarrell / bash_profile

Created July 7, 2015 11:02

	# setting ALTERNATE_EDITOR to the empty string "" instructs
	# emacsclient to invoke Emacs in daemon-mode iff it isn't running already
	export EDITOR=emacsclient
	export ALTERNATE_EDITOR=""

RichardBarrell / Cargo.toml

Created October 31, 2014 12:40

	[package]
	name = "ie_counts"
	version = "0.0.1"
	authors = ["Richard Barrell <[email protected]>"]

	[[bin]]
	name = "ie_counts"
	crate-type = ["staticlib"]

RichardBarrell / FindBirthday.hs

Created October 23, 2014 13:32

	module FindBirthday where

	-- compile as: ghc --make FindBirthday.hs -main-is FindBirthday.main
	-- or run as: runhaskell FindBirthday.hs
	-- and answer "y" or "n" when the program asks you a question. :)

	import Data.Time (formatTime, addDays)
	import System.Locale (defaultTimeLocale)

	-- use 2014 because that was a leap year, and we need all 366 days.

RichardBarrell / silly_bars.html

Created October 9, 2014 00:06

	<!doctype html>
	<html><head><meta charset="UTF-8" />
	<title>Odd layout example.</title>
	<style type="text/css">
	#evil-container {
	position: relative;
	background: #aaffaa;
	}
	body, #evil-container {
	width: 100%;

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