Reminders

bash: set -euxo pipefail

#!/usr/bin/env bash set -euxo pipefail Explanations from the Bash Reference Manual: -e Exit immediately if a pipeline, which may consist of a single simple command, a list, or a compound command returns a non-zero status. -u Treat unset variables and parameters other than the special parameters ‘@’ or ‘*’, or array variables subscripted with ‘@’ or ‘*’, as an error when performing parameter expansion. An error message will be written to the standard error, and a non-interactive shell will exit....

Detect dark mode in javascript

A reminder to myself, because I’ve forgotten this too many times and had to look it up again and again. if (window.matchMedia) { if (window.matchMedia('(prefers-color-scheme: dark)').matches) { const body = document.getElementsByTagName('body')[0]; body.classList.add('dark'); } } ...

New Developer Booklist

Welcome friend. Here’s something for you to read so that we can have some awesome arguments. The Pragmatic Programmer Design Patterns: Elements of Reusable Object-Oriented Software Refactoring: Improving the Design of Existing Code Domain-Driven Design: Tackling Complexity in the Heart of Software Working Effectively with Legacy Code Growing Object-Oriented Software, Guided by Tests Release It!: Design and Deploy Production-Ready Software Continuous Delivery: Reliable Software Releases through Build, Test, and Deployment Automation Building Microservices Pragmatic Thinking and Learning: Refactor Your Wetware Drift into Failure: From Hunting Broken Components to Understanding Complex Systems Building Evolutionary Architectures ...

Git revision of a single file

git --no-pager log -1 --pretty=%h <filepath> ...

How to use rsync on OSX

I don’t really want to copy dot files (eg. .DS_Store), and I want to avoid the bug that rsync exhibits with time-capsule where it loops creating multiple ..DS_Store.xxxx files. rsync -vrW --ignore-existing --exclude ".*" --progress ~/Movies/ /Volumes/Backup/Movies/ ...

How to delete all zero length files in a directory tree

find . -type f -size 0 -print0 | xargs -0 rm -f ...

Cross-Site Scripting vulnerability with JavaScript and JQuery

Think you’ve protected your site against Cross-Site scripting attacks by escaping all the content that you’ve rendered? Thought about your javascript? Here’s a neat bug that got us today. This example is contrived to show a point. <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>XSS Example</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> <script> $(function() { $('#users').each(function() { var select = $(this); var option = select.children('option').first(); select.after(option.text()); select.hide(); }); }); </script> </head> <body> <form method="post"> <p> <select id="users" name="users"> <option value="bad">&lt;script&gt;alert(&#x27;xss&#x27;);&lt;/script&gt;</option> </select> </p> </form> </body> </html> See the problem?...

Apache Ivy and Spring EBR

Here is how I set up the Apache Ivy dependency manager so that it can fetch springframework JARs from the SpringSource Enterprise Bundle Repository. Listing: ivysettings-custom.xml <ivysettings> <resolvers> <url name="com.springsource.repository.bundles.release"> <ivy pattern="http://repository.springsource.com/ivy/bundles/release/[organisation]/[module]/[revision]/[artifact]-[revision].[ext]" /> <artifact pattern="http://repository.springsource.com/ivy/bundles/release/[organisation]/[module]/[revision]/[artifact]-[revision].[ext]" /> </url> <url name="com.springsource.repository.bundles.external"> <ivy pattern="http://repository.springsource.com/ivy/bundles/external/[organisation]/[module]/[revision]/[artifact]-[revision].[ext]" /> <artifact pattern="http://repository.springsource.com/ivy/bundles/external/[organisation]/[module]/[revision]/[artifact]-[revision].[ext]" /> </url> <chain name="spring"> <resolver ref="com.springsource.repository.bundles.release"/> <resolver ref="com.springsource.repository.bundles.external"/> </chain> <ibiblio name="jboss" root="http://repository.jboss.org/maven2/" m2compatible="true"/> <chain name="main" dual="true"> <resolver ref="shared" /> <resolver ref="public" /> <resolver ref="spring" /> <resolver ref="jboss" /> </chain> <chain name="default" returnFirst="true"> <resolver ref="local" /> <resolver ref="main" /> </chain> </resolvers> </ivysettings> Listing: ivysettings....

Jsoup - BeautifulSoup for Java

HTML is notoriously difficult to parse and it has usually been a pain to do this in Java. Yes I know that there are parsers (like jtidy and nekohtml) that try to create a proper DOM but I’ve been waiting for something more lightweight. Enter Jsoup. It feels like a mix of JQuery and Beautiful Soup (for Python). String html = response.getContentAsString(); Document document = Jsoup.parse(html); Elements elements = document.select("#errorRef"); assertThat(elements....

PostgreSQL & Python on Mac

I've been playing with Django & MySQL for a while but for my next project I wanted to integrate it with a PostgreSQL database. Everything went well until I wanted to install Psycopg as my python adapter to PostgreSQL. After a bit of blundering about here's what it eventually took: Download and install PostgreSQL one-click installer from http://www.postgresql.org/download/macosx. Remember to read the README file before actually running the installer. Download the psycopg2 source from http://initd....