Zhixian's Tech Blog


Installing Git

Filed under: Uncategorized — Zhixian @ 23:00:10 pm


$ sudo apt-get install git

Basic Setup

$ git config --global user.email "you@example.com"
$ git config --global user.name "Your Name"




Setup Ubuntu (Trusty Tahr) for development

Filed under: development, ubuntu — Tags: , , , , — Zhixian @ 11:18:10 am

This blog post is on my setting up another Ubuntu Server VM.
This time I want a VM that has the common software development applications pre-installed.
As such most of the steps are similar to what I did in a previous blog post.
So on this blog post, I will start from the screen where I can select pre-packaged software.


Although, I was not really sure I really need the DNS server and print server, I thought “Ah well. Might as well.”
So they are included.

Setup MySql

First thing to setup is to assign a password for MySql server “root” account.
Note: You may have notice that background color have changed from purple to blue.
This was because I typed the wrong confirmation password when setting the password.




Setup E-mail










Connecting to OpenSSH server using MobaXterm

Filed under: computing, ubuntu — Tags: , , , , , — Zhixian @ 14:19:10 pm

This blog post covers connecting to the openssh server installed on Ubuntu server using MobaXterm.

Testing OpenSSH

I want to connect to the openssh server.
For this purpose, I use MobaXterm from Mobatek (http://mobaxterm.mobatek.net/).
This is a terminal application with a few other tools built-in.
It has a professional edition which cost money and a home edition that is free.
For our local development purpose, the free edition is fine.

Alternatively, there’s the putty-series (http://www.putty.org/) of applications.

The remainder of this session assumes you are using MobaXterm.

After you start up MobaXterm, you may see a window like the below.
Click on the Session button on the menu.
This will open the Session Settings dialog.


On the Session Settings dialog, click on the SSH button on the top menu.


Under the Basic SSH settings tab, enter the name of the remote host.
Click the OK button to connect to the server.


After you clicked OK, MobaXterm will start your session on a new tab.
You should see your usual login prompt.
You should be able to login to your account as usual.


File transfer using SFTP

You can transfer files from your Windows machine to your Ubuntu machine using SFTP (Secure-FTP).
One the tools built-in the MobaXterm client is a SFTP client.
Click on the SFTP tab to display the directory and files in the directory.


To transfer files, simple drag and drop the files that you want to transfer in the area showing files in specified directory.

Ubuntu Server Initial Setup

Filed under: computing, ubuntu — Tags: , , , , , — Zhixian @ 13:29:10 pm

After you have installed your Ubuntu server, you may want to do some initial setup.
Specifically, you may want to add a another account.

Adding user account

Adding users can be done using the command adduser. In the below command-line, I am creating a developer account call ‘developer’.

$ sudo adduser developer


After you have create the user account, it might be useful to add the account to the ‘sudo’ group so that the account can make use of the ‘sudo’ command. To do so,

$ sudo addgroup developer sudo


You can check which groups an account belongs to using the ‘groups’ command:

$ groups developer



Setting up Ubuntu 14.04 Server on VirtualBox

Filed under: computing, ubuntu — Tags: , , , , — Zhixian @ 17:15:10 pm

This is a blog post that describes my setup of Ubuntu Server 14.04 (Trusty Tahr) on VirtualBox.
I intended to use this server for local software development.

Selected Software Package Description
OpenSSH server Needed for remote secure shell sessions
LAMP Linux Apache MySql PHP development stack
PostgreSQL database Best open-source database
Samba file server File sharing
Skipped Software Packages Description
DNS server Don’t really think I need it
Mail server I will describe this in a later blog post
Print server Don’t really think I need it
Tomcat Java Server Not sure if I want to use this;


























































done function not called in jQuery AJAX call

Filed under: development, web application development — Tags: , , — Zhixian @ 23:40:02 pm

In jQuery, you can write an AJAX call that is chained to a done function.
Sometimes this function does not get called.

One of things to examine is the response that you are receiving from the server.
If the response is malformed, the done function will not get triggered.

An example of a malformed response:

{ "result" : OK }

Correct reponse (note the presence of quotation marks around OK:

{ "result" : "OK" }


Can not load type MembershipPasswordAttribute using ASP.NET (Mono)

Filed under: web application development — Tags: , , , — Zhixian @ 08:33:01 am

Note: This blog post does not provide a solution.


Recently, I was trying to build a ASP.NET MVC project using Mono on my Ubuntu machine.
It did not end well.

While building the login page, I got this error message.

Could not load type ‘System.Web.Security.MembershipPasswordAttribute’ from assembly ‘System.Web, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’.

Error 500 - Google Chrome_201

The offending code is:

test.mvc.web - Views-Home-Index.cshtml - MonoDevelop_202

As it turns PasswordFor is not the only helper extension that will trigger this error.
TextBoxFor have the same issue as well.

Why this happens

As it turns out, the Mono 4.5 that I am using at this time of writing does not have this implemented yet.

You can view here (http://go-mono.com/status/status.aspx?reference=4.5&profile=4.5&assembly=System.Web).

Mono System.Web in 4.5 vs MS.NET 4.5 - Google Chrome_203


No good solution to this issue currently.

One possible workaround is not to use the HTML Helper extensions.


Install nunit on Ubuntu

Filed under: computing — Tags: , , — Zhixian @ 23:34:01 pm

To install nunit on Ubuntu, start a terminal session and execute the following command:

sudo apt-get install nunit nunit-console nunit-gui

zhixian@SARA: ~_200

After installation has complete, you can run nunit by executing the following command in the terminal session:


for the user-friendly graphical interface or alternatively,


for the nunit console.


How to install xsp4 onto Ubuntu

Filed under: computing — Tags: , , — Zhixian @ 09:14:01 am

I just realise that the mono-complete does not include the xsp4 package.
This package is needed if you intend to debug web applications using MonoDevelop.

sudo apt-get install mono-xsp4

zhixian@SARA: ~_196

After the installation process has complete, you may see a message stating that you have an incomplete debian.webapp.

zhixian@SARA: ~_199

To remedy this, install asp.net-examples by running the below command:

sudo apt-get install asp.net-examples

zhixian@SARA: ~_198


Installing Postgresql using installer from EnterpriseDB on Ubuntu

Filed under: computing — Tags: , , , , , , , — Zhixian @ 17:23:01 pm

This blog post describes installing Postgresql 9.4 and pgAdmin III 1.20.0 using the installer provided by EnterpriseDB.

Background (Or lessons learnt)

I recently installed a copy of Postgresql on Ubuntu based on instructions from the official web site (http://www.postgresql.org/download/linux/ubuntu/).
Unfortunately, the copy of pgAdmin III (a graphical UI to manage Postgresql databases) is outdated.
The version of Postgresql installed was 9.4 but the version of pgAdmin installed was 1.18.1 which has warnings issued when I connect to the database.

pgAdmin III_168

So I decide to do the next best thing mentioned in the page – use the installer from EnterpriseDB in hopes that they have packaged the latest copy of pgAdmin III.

PostgreSQL: Linux downloads (Ubuntu) - Google Chrome_171


I assumed you know how to start a terminal session and execute commands in it.

Summary of Steps

  1. Download Installer
  2. Making Installer executable
  3. Execute the Installer

Download Installer

Clicking the download link in the previous screen shot will bring me to the EnterpriseDB’s Postgresql install download page (http://www.enterprisedb.com/products-services-training/pgdownload).

Because I’m running the 64-bit version of Ubuntu, I clicked on the “Linux x86-64” button to download the installer.

Download PostgreSQL | EnterpriseDB - Google Chrome_172

After you clicked the button, you will be brought to a thank-you page.
Wait for the download to complete.

Thank you for downloading PostgreSQL! | EnterpriseDB - Google Chrome_173

After the download has complete, your download folder should look like the below.


Making Installer executable

By default, the downloaded file is not executable by double-clicking it.
Attempts to do so, will result in the below dialog:

Untitled window_175

Click on the No button to close the dialog.

To make the downloaded file executable:

1. Start a terminal session and navigate to folder where you saved the downloaded installer.

zhixian@SARA: ~-Downloads_176

2. Run the following command. Replace the text in bold if necessary if you are not using Ubuntu 64-bit.

chmod +x ./postgresql-9.4.0-1-linux-x64.run

zhixian@SARA: ~-Downloads_177

Execute the installer

Now you can execute the installer. From the terminal session, run the following command start the installation wizard:

sudo ./postgresql-9.4.0-1-linux-x64.run

zhixian@SARA: ~-Downloads_180

You will see the welcome screen of the installation wizard.
Click on Next button to proceed to the next step of the installation wizard.

Setup (as superuser)_181

The installation wizard should prompt you for the location to install Postgresql.
Click on Next button to accept the default and proceed to the next step of the installation wizard.

Setup (as superuser)_182

The installation wizard will now prompt you for the directory to store data for Postgresql.
Click on Next button to accept the default and proceed to the next step of the installation wizard.

Setup (as superuser)_183

The installation wizard will now prompt you for a password to the postgres account.
This account is use for starting Postgresql.
Enter your desired password for this account.
Click on Next button to accept the default and proceed to the next step of the installation wizard.

Setup (as superuser)_184

The installation process will then prompt you for a port number that Postgresql will use to host the database server.
Click on Next button to accept the default and proceed to the next step of the installation wizard.

Note The default port that Postgresql use is 5432. However, this port is all in used by the first instance of Postgresql that I installed previously the installation wizard picked the next available port 5433. I accepted the defaults in the screen shot below planning to uninstall the first instance of Postgres and then reconfigure this instance of Postgresql to use port 5432.

Setup (as superuser)_185

The installation wizard will now prompt you for the locale that your database will use.
Click on Next button to accept the default and proceed to the next step of the installation wizard.

Setup (as superuser)_186

The installation will now declare that it has all the information need to install Postgresql.
Click on Next button to accept the default and proceed with installing Postgresql.

Setup (as superuser)_187

The installation wizard will start to install Postgresql.
Wait for the installation process to complete.

Setup (as superuser)_188

After the installation process has complete, you will see the below screen.
Click on Finish button to exit the installer.

Note If you not need to download and install additional software, uncheck the option to start Stack Builder at exit.

Setup (as superuser)_189

After you exit the installation wizard, you should be able to see the Postgresql that you just installed from the desktop menu.

Workspace 1_195

Note If you do not see the menu item, you may need to re-login or restart your system.

The pgadmin installed should be version 1.20 and should work fine with Postgresql 9.4.

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