ozooxo

beta@landlubber:~$ uname -a
Linux landlubber 3.13.0-46-generic #79-Ubuntu SMP Tue Mar 10 20:06:50 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
beta@landlubber:~$ java -version
java version "1.7.0_76"
Java(TM) SE Runtime Environment (build 1.7.0_76-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.76-b04, mixed mode)
beta@landlubber:~$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
[sudo] password for beta: 
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.OFXWl1OKUd --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyring /etc/apt/trusted.gpg.d/minecraft-installer-peeps-minecraft-installer.gpg --keyring /etc/apt/trusted.gpg.d/webupd8team-java.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
gpg: requesting key 7F0CEB10 from hkp server keyserver.ubuntu.com

ozooxo

beta@landlubber:/usr/lib/java$ update-alternatives --get-selections | grep java # java jvm location can be found using this command
appletviewer                   manual   /usr/lib/jvm/java-7-oracle/bin/appletviewer
ControlPanel                   manual   /usr/lib/jvm/java-7-oracle/jre/bin/ControlPanel
extcheck                       manual   /usr/lib/jvm/java-7-oracle/bin/extcheck
idlj                           manual   /usr/lib/jvm/java-7-oracle/bin/idlj
itweb-settings                 auto     /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/itweb-settings
jar                            manual   /usr/lib/jvm/java-7-oracle/bin/jar
jarsigner                      manual   /usr/lib/jvm/java-7-oracle/bin/jarsigner
java                           manual   /usr/lib/jvm/java-7-oracle/jre/bin/java
javac                          manual   /usr/lib/jvm/java-7-oracle/bin/javac

ozooxo

linux這邊就沒有事先被compile好的版本，具體compile可以follow這個link。

cd ~/opencv
mkdir release
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
make
sudo make install

ozooxo

Cause

I face this problem because I accidentally try to install MongoDB 3.0.x (from http://repo.mongodb.org/apt/ubuntu) while actually a MongoDB 2.6.8 (provided by ubuntu) is already installed in the same computer. Therefore, both mongod and mongo commands are still point to the old version (which doesn't work actually). Since the official installation document said that "You cannot install this package concurrently with the mongodb, mongodb-server, or mongodb-clients packages provided by Ubuntu", this just cannot work.

A better way is to first completely uninstalled the older version before install the new one, but I already missed that time. So

sudo apt-get purge mongodb mongodb-clients mongodb-server mongodb-dev
sudo apt-get purge mongodb-10gen

cannot remove it completely (not sure whether that's the exact case), and \usr\bin\mongo and ``\usr\bin\mongo

ozooxo

My original plan is to setup a good viewing environment for markdown files (analyzing results produced by some template engine). No blog functions are needed. However, it turns out to be tedious and not as useful as expected.

To setup Ruby, basically following this link is fine. Note that rails (or at least node.js) is needed. Pure ruby is not enough.

To setup Jekyll, following this link. After installation, running

$ bundle exec jekyll serve

ozooxo

Tomcat7

Setup tomcat7 is easy. Just do

sudo apt-get install tomcat7

and http://localhost:8080/ will work already. The default source files are in /usr/share/tomcat7, while the default path is in /var/lib/tomcat7/webapps/ROOT.

ozooxo

beta@landmark:~/Downloads$ sudo apt-get install nodejs
beta@landmark:~/Downloads$ sudo apt-get install npm
beta@landmark:~/Downloads$ npm install highlight.js
beta@landmark:~/Downloads$ node
> var hljs = require('highlight.js');
undefined
> hljs.highlightAuto("<p>abc</p>").language;
'xml'

ozooxo

After trying to repair the touch-pad of my Ubuntu 12.04, the system cannot boot from X Window. It turns out that xserver-xorg is accidentally removed by sudo apt-get autoremove process after I installed xserver-xorg-input-synaptics. To repair it, just go to the recovery mode and

sudo apt-get install xserver-xorg
sudo dpkg-reconfigure xserver-xorg

ozooxo

sudo update-alternatives --config javac 
sudo update-alternatives --config java

ozooxo

Basically follow this link will work.

To give access of remote users using postgresql-client, one need to add the following line in /etc/postgresql/9.3/main/pg_hba.conf.

host    all             all             0.0.0.0/0               md5