Posts from May 2021 [ on iamcal.com ]

Posts from May 2021

May 18th: This write up on finding arbitrary code execution in ExifTool is interesting both because it's Perl code that I used almost 20 year ago (and is still the best way to do it!), and that it's a great explanation of finding and exploiting vulnerable code.

May 9th: While researching the different colored bands for bundles of American bank notes, I found this fascinating page about the rules for US currency deposits.

Geography

I thought my geography was reasonable, but I only hit 52 of the 150 largest countries by area. You get a few tries per country.

The harder version has all 193 members of the UN.

May 4th: It's been three and a half months since I got PHP CI working on Travis, so of course it's now broken. Github Actions are the new hotness, so I figured out the right magical config to run multi-version CI for PHP over there instead, and it runs much faster too.

IBM Wiring

I'd seen the photo a few times, but this is the first I'd read about what was actually being wired up. Turns out it's a semi-mechanical pre-computer for accounting and it's even more interesting than it first looked.

About

This is the personal website of Cal Henderson, Slack co-founder & CTO.

I give occasional talks, write code and sometimes articles.

» About Cal

Archives

2024:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct
2023:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2022:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2021:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2020:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2019:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2018:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2017:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2016:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2015:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2014:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2013:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2012:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2011:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2010:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2009:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2008:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2007:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2006:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2005:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2004:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2003:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2002:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2001:	Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2000:	Jun Jul Aug Sep Oct Nov Dec

Recent Tags

books bools cheese code covid food games halflife havana ibm language lego maps math memes minecraft php programming reading regex slack technology via-matts wiring

iamcal.com Since May 2000