How to know your computer architecture (32 / 64 bit) ?

Open a terminal and type following command,

uname -m

Result

i686 = 32 bit
x86_64 = 64 bit

How to clear all data in a column in a MySQL database table

In certain cases its essential to clear all data in a particular column in a table.
For example a database name is school
There is a table inside school is student
A column inside school is email 

Column email contains email ids of about 100 students.
Apply following command, if you want to clean all email id entries from email column.

mysql -uroot -p  [enter mysql root password]

You can get mysql command prompt, enter following commands there;

use school;
UPDATE `student` SET `email` = '';
quit;

Now email column inside student table is clean.

Install Flash player in Ubuntu using command

Here is the command,

sudo apt-get install flashplugin-installer

How to find CPU architecture information

In certain situations, you have to find PC architecture (32 bit / 63 bit) for various purposes. Here is a simple command to display Linux architecture information.

lscpu

The result is,

Install Whisker menu on Xubuntu 12.04 /XFCE 4

Whisker menu is an application launcher available with XFCE 4. Very easy to find and launch applications with the help of Whisker menu.

 

Install  Whisker menu on Xubuntu 12.04

Apply following commands,

sudo add-apt-repository ppa:gottcode/gcppa
sudo apt-get update
sudo apt-get install xfce4-whiskermenu-plugin

Remove your default menu and add Whisker menu from panel properties.

Panel > Add New Items > Whisker Menu

View your network information

This command is helpful to collect information about your network details.
Open a terminal and apply following command,

nm-tool

See the result.

Installing Dspace 3.x on Ubuntu 12.04

Installation of prerequisite applications

Open  Applications > Accessories > Terminal and execute following commands. Text in italics are commands to be executed.

sudo apt-get install openjdk-7-jdk

sudo apt-get install tasksel sudo tasksel

Select the following packages. Use space bar for select applications from list. [*] LAMP server [*] PostgreSQL database [*] Tomcat Java server  use tab to select OK button and enter. Packages will start to install. On the way you have to give MySQL root password. MySQL not necessary for Dspace installation.

sudo apt-get install ant maven

 

Create the database user (dspace)

sudo su postgres createuser -U postgres -d -A -P dspace

enter password for new role (select a password like dspace) Shall the new role be allowed to create more new roles? (y/n) n

Exit from the promp, type exit

Allow the database user (dspace) to connect to the database [If the following command not open, check the postgresql version number and apply in the command]

sudo gedit /etc/postgresql/9.1/main/pg_hba.conf

Add this line to the configuration file at the end:   

local all dspace md5 

save and close the file 

Restart PostgreSQL : sudo su      enter,

then paste the following line and enter

/etc/init.d/postgresql restart

Create the Unix 'dspace' user, update the passwd, create the directory in which you will install dspace, and ensure that the Unix 'dspace' user has write privileges on that directory:

sudo useradd -m dspace

sudo passwd dspace (enter any password like dspace for the new user dspace)

sudo mkdir /dspace

sudo chown dspace /dspace

Create the PostgreSQL 'dspace' database.

 

sudo -u dspace createdb -U dspace -E UNICODE dspace  

Configure Tomcat to know about the DSpace webapps.
[If the following command not open, check the tomcat version number and apply in the command]

sudo gedit /etc/tomcat7/server.xml

Insert the following chunk of text just above the closing </Host>  <!-- Define a new context path for all DSpace web apps --> <Context path="/xmlui" docBase="/dspace/webapps/xmlui" allowLinking="true"/> <Context path="/sword" docBase="/dspace/webapps/sword" allowLinking="true"/> <Context path="/oai" docBase="/dspace/webapps/oai" allowLinking="true"/> <Context path="/jspui" docBase="/dspace/webapps/jspui" allowLinking="true"/> <Context path="/lni" docBase="/dspace/webapps/lni" allowLinking="true"/> <Context path="/solr" docBase="/dspace/webapps/solr" allowLinking="true"/>

save and close  the file a

This following  step downloads the compressed archive from SourceForge, and unpacks it in your current directory. The dspace-1.x.x-src-release directory is typically referred to as [dspace-src]. You can also download direct from Sourceforge website.

sudo mkdir /build

sudo chmod -R 777 /build

cd /build

wget http://downloads.sourceforge.net/project/dspace/DSpace%20Stable/3.1/dspace-3.1-release.tar.bz2 

tar -xvjf dspace-3.1-src-release.tar.bz2

cd /build/dspace-3.1-src-release

mvn -U package cd dspace/target/dspace-3.1-build

sudo ant fresh_install 

 

Fix Tomcat permissions, and restart the Tomcat server

sudo chown tomcat7:tomcat7 /dspace -R

Restart Tomcat

/etc/init.d/tomcat7 restart

 Make an initial administrator account (an e-person) in DSpace:

/dspace/bin/dspace create-administrator

Test it out in your browser

That is all that is required to install DSpace on Ubuntu. There are two main webapps that provide a similar turn-key repository interface

http://localhost:8080/xmlui

http://localhost:8080/jspui

Reference