Java on Mac OS X

Current version of Java

$> java -version

What java executable is command line using

$> ls -al /usr/bin/java

What versions of java exist on system

$> /usr/libexec/java_home -v version.xx

… i.e. if you execute..

$> /usr/libexec/java_home -v 1.7

… it’ll output the runtime lib directory. If you you use a version number that’s not installed it’ll just tell you that it can’t find a directory. In which case you need to install it.
You can also list the java frameworks library directory, but I’ve found this to be inconsistent with new java versions I install…

$> ls /System/Library/Frameworks/JavaVM.framework/Versions/

Installing JDK
To update the command line java we need to download the jdk, not just the jre that the default “google java download” prompts you to. We then need to make sure our env vars (ie JAVA_HOME) are set in .bash_profile.
JDK 8 Installation for OS X (oracle docs)
OS X Platform Install FAQ
Java SE Development Kit 8 Downloads

Sometimes it’s necessary to have multiple jdk versions on your system depending on what you’re running/compiling. Search for “java archive” (it’s at the bottom) to list previous java versions on downloads page…
Java SE Downloads

If we want to switch between java versions we can use the JAVA_HOME env var..

$> export JAVA_HOME=`/usr/libexec/java_home -v version.xx`

Linux Chromebook

Putting Linux on your Chromebook is easier than you think (and totally worth it!)

How to Install Ubuntu Linux on Your Chromebook with Crouton

How to Enable Developer Mode on Your Chromebook

How to Install and Run Linux on a Chromebook

Crouton (GitHub)

Chrome Crouton Extension
XFCE

How to Manage the Crouton Linux System on Your Chromebook

Recover your Chromebook

How To Create a Chromebook Recovery Image

Four Of The Best Text Editors For Your Chromebook
Command line from localhost terminal “chronos@localhost” asking for root password that doesn’t match one we in startup wizard
– “for what it’s worth, I discovered the following: the root password you set when enabling debugging tools will work over SSH but will NOT work from the local shell. if you ssh in as root, you can then change all the passwords to be what you want.”
– ssh root@localhost
– passwd chronos

sudo startxfce4
root

Dev Ops Stuff

Running Bash Commands in the Background the Right Way [Linux]

Linux: Start Command In Background

How To Use Bash’s Job Control to Manage Foreground and Background Processes

How can I wake a process from sleep status via signal or /proc?

Move Running Process to Background & Nohup

JOBS & PROCESS CONTROL – moving process to background – a new process, or a running process – bg/fg & the difference between disown/disown -h/nohup

How to Find Files and Folders in Linux Using the Command Line
How to Get Default Gateway Address in Mac OS X

Find a Router IP Address in Mac OS X

How to get permission number by string : -rw-r–r–

Display The List Of Recently Installed Packages By Date On Ubuntu

How can I view last installed package or program?

How To Use Netcat to Establish and Test TCP and UDP Connections on a VPS

How can I import a large (14 GB) MySQL dump file into a new MySQL database?

Solve Wi-Fi Coverage Problems with WiFi Explorer and NetSpot

Vi Command Cheat Sheets

18 Tar Command Examples in Linux

“chroot” Command Usage Examples in Linux

Linux / Unix: chroot Command Examples

How To Set Up vsftpd for a User’s Directory on Ubuntu 16.04

Linux rename command – How to rename multiple files by replacing word in file name?

Linux rename command in Mac OS

CPU performance measuring in linux perf tool

Basics of the Unix Philosophy

5 Ways to Download Complete Websites For Offline Access

Camera Not Detected on Mac

This is what worked for me. Essentially killing the VDCAssistant process and letting it automatically restart itself. I didn’t even have to restart my video chat app I was using to see make the video work!

mac-pro$ ps aux | grep VDCAssistant
root            71691   1.4  0.3  2568156  24452   ??  Ss    2:33PM   0:00.51 /System/Library/Frameworks/CoreMediaIO.framework/Resources/VDC.plugin/Contents/Resources/VDCAssistant
mac-pro$ sudo kill {{pid listed in grep command.. in this case it's 71691}}

Links:
Fixing “There is no connected camera” Error with a Mac FaceTime Camera