WARNING: UNPROTECTED PRIVATE KEY FILE When Copying SSH Public/Private Key Files

How I cleared the `WARNING: UNPROTECTED PRIVATE KEY FILE` error by tightening private key permissions with `chmod 600`.

[Mac] How to Configure ll Command to Execute ls -l Command

Adding an alias in `.bashrc` so `ll` works as `ls -l` on Mac.

[Eclipse] Java/Tomcat Configuration Change Memo When Switching Projects

A checklist of Java and Tomcat settings to update when switching between Eclipse projects.

[Facebook] Developer/HTML5 Blog, Weekly Platform Updates, Platform Status and Other Information Now Available via Email Subscription

Facebook Developers now offers email subscriptions to its Developer Blog, HTML5 Blog, Weekly Platform Updates, and Platform Status.

[RVM][Ruby] ERROR: Loading command: install (LoadError) cannot load such file -- zlib, ERROR: While executing gem ... (NameError) uninitialized constant Gem::Commands::InstallCommand

Fixing a zlib LoadError from gem install by reinstalling Ruby 1.9.3 with RVM without the -C path options.

[Mac] GNU GCC 4.2 is Not Supported from Xcode 4.2

A note that Xcode 4.2 dropped GNU GCC 4.2 support, leaving only LLVM-based compilers.

[Mac] How to Downgrade from Xcode 4.2 to 4.1

Downgrading Xcode 4.2 to 4.1 on Mac OS X Lion to work around an rvm warning while installing Ruby 1.9.2.

[RVM][Mac] Error running 'make ', please read ruby-1.9.2-p290/make.log

Working around a Ruby 1.9.2 make error on Mac OS X Lion by installing apple-gcc42 and using CC=gcc-4.2.

Steps to Build Ruby Development Environment with RVM on Mac OS X Lion

Setting up Ruby 1.8.7 / 1.9.2 / 1.9.3 on Mac OS X Lion with RVM, from apple-gcc42 to default version selection.

List of Ruby Versions Available for Installation with RVM

Using rvm list known to check the Ruby versions available for installation via RVM.

[RVM] How to Uninstall Ruby Version Management System RVM

You can uninstall RVM by simply running `rvm implode` or `rvm seppuku`.

[Mac] How to Install apple-gcc42 with Homebrew

How to install apple-gcc42 from the homebrew-dupes Formula and use the classic gcc-4.2 command on macOS.

[Symfony2] About DB Master/Slave Configuration

Master/Slave DB options for Symfony2 — Doctrine DBAL's MasterSlaveConnection and EntityManager switching.

[JavaScript] Installing SpiderMonkey on Mac with Homebrew

Installing SpiderMonkey with Homebrew so you can run JavaScript from the console via the js command.

[Facebook] How to Display Page Wall Icons with Proper Size Matching for Better Visibility

A quick note on getting Facebook Page wall thumbnails to look crisp by matching their pixel dimensions.

[Mac] After Installing Homebrew, Got Error "Warning: Now install Xcode: http://developer.apple.com/technologies/xcode.html"

The 'Warning: Now install Xcode' Homebrew message was fixed by installing Xcode from the App Store.

[Facebook] Reasons Why Images Become Rough and Blurry, and Solutions

Why Facebook Page profile images look blurry (JPEG mosquito noise) and a suggested workaround using more complex colors.

[Domain] Onamae.com DNS Record Configuration Propagation Time

Onamae.com's FAQ says 24-72 hours, but my rental DNS record change propagated in a few minutes.

[PHP] Chrome Extension 'php-console' for Checking Errors from Browser

A note on 'php-console', a Chrome extension for viewing PHP errors right in the browser.

[Ubuntu] How to Install aptitude [11.10]

Installing aptitude on Ubuntu 11.10 via sudo apt-get -y install aptitude.

[Apache][Error] httpd: apr_sockaddr_info_get() failed for

Fixing Apache's apr_sockaddr_info_get() failed error by aligning /etc/hosts, network config, and httpd.conf ServerName.

[Ubuntu] Installing Vim-gnome

Installing vim-gnome via aptitude on Ubuntu and clearing gvim's Gtk-WARNING with gtk2-engines-pixbuf.

[Ubuntu] Things to Do Right After Installing 11.10 (Settings and Software to Add)

A memo of things to do right after installing Ubuntu 11.10 Oneiric Ocelot, with a reference walkthrough.

[Ubuntu] How to Launch Terminal [11.10]

Three ways to launch the terminal on Ubuntu 11.10, including the Ctrl + Alt + T shortcut.

[Apache][Error] configure: error: no acceptable C compiler found in $PATH

Installing gcc and gcc-c++ via yum resolved the 'no acceptable C compiler' error when building Apache from source.

[DoS Attack] Teardrop Attack

A note on Teardrop, a DoS attack that abuses overlapping IP-fragment offsets to crash vulnerable TCP/IP stacks.

[HTML/CSS] Tool for Measuring Size (px) on Web Pages: 'MeasureIt!' [Chrome][Firefox]

MeasureIt! is a Chrome / Firefox extension for measuring pixel sizes directly on web pages.

[Java] Calendar Class for Handling Date and Time Information

A short memo of reference links for handling dates and times in Java with the Calendar class.

[Free Software] Windows App 'PNGGauntlet' for Lossless PNG Image Compression

PNGGauntlet is a Windows freeware tool for lossless PNG compression, useful for web performance.

Picasion: Web Service for Easily Creating GIF Animations

Picasion is a web service that turns uploaded images into a GIF animation in just a few clicks.

[Facebook] Getting Profile Image URLs in Various Sizes

How to fetch Facebook profile picture URLs via the Graph API, with size options and SSL support.

[Ruby on Rails] How to Display Confirmation Dialog After Pressing Form Submit Button

Pass a :confirm message to submit_tag in Rails 3.1 to show a confirmation dialog on submit.

[PHP] Setting Language Environment to Japanese with mbstring.language="japanese"

Set PHP's language environment to Japanese via mbstring.language in php.ini.

[PHP] How to Execute phpinfo() from Command Line

How to run phpinfo() straight from the Linux command line using php -r 'phpinfo();'.

[Tomcat] How to Change Port Number Configuration

Change Tomcat's port from 8080 to 80 by editing the Connector in tomcat/conf/server.xml.

[LDAP] How to Change Password for Registered Entries (ldappasswd Command)

A quick note on changing an LDAP entry password with the ldappasswd command.

[Windows] How to Uninstall Apache

Steps to uninstall Apache HTTP Server from Windows 7.

[Python] How to Do 'Scraping' to Extract Only Necessary Data from Websites Using BeautifulSoup

Extracting only the links from a web page with Python's BeautifulSoup library as a first taste of scraping.

[Python] How to Handle Static Files (js, css, images, etc.) in web.py

Placing js, css, and images under a `static` directory to serve them from a web.py app.

[Python] Converting, Replacing, and Removing Line Breaks with string.replace()

Using Python's string.replace() to convert, replace, or strip line-break characters like `\r\n`.

[Resources] 'Let's Read the World's JavaScript @ 2012'

A slide deck that summarizes the JavaScript landscape and information-gathering methods circa 2012.

Summary of Commonly Used Commands and Flow for Web App Development with Heroku + Ruby on Rails 3.2

Commands and workflow for building and deploying a Rails 3.2 app to Heroku's Cedar stack, end to end.

[Firefox][Add-on] FireMobileSimulator Add-on for Simulating Major Three Carriers (DoCoMo/Au/SoftBank) Mobile Device Browsers

Introducing FireMobileSimulator, a Firefox add-on that simulates DoCoMo, Au, and SoftBank feature-phone browsers on a PC.

[Network] Subnet Mask Reference Table

A quick lookup table of subnet masks — IP counts, dotted mask values, and prefix lengths.

[Mac] Installing tree Command with Homebrew

Installing the tree command on macOS via Homebrew to visualize directory structures.

[JavaScript] Reading Google Analytics ga.js Source Code After Restoration

Restoring the compressed ga.js of Google Analytics with JsDecoder and reading its source.

[JavaScript] Reading Google Analytics Urchin Module Source Code

Reading through the legacy Google Analytics Urchin Module (urchin.js) source code.

[Ruby on Rails] URL Encoding (url_encode) in ERB

Notes on URL-encoding strings inside ERB with the url_encode helper and its short form u.

[iTerm] How to Set Window Background Transparency

Enable a translucent iTerm window from Preferences → Profiles → Window → Transparency.

[Technical Terms] Official Names of SYN and ACK in TCP 3-Way Handshake

A short memo on the official names of SYN and ACK in the TCP 3-way handshake, and how the connection is established.