Hilary Ho

Everything you need to know about ME and Computers

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Cannot Take Ownership VMWare Player / Workstation

Recently I experienced a power failure at my office when I was running two different virtual machines.  Upon restarting, I am unable to connect to the machines as VMWare tells me "This virtual machine appears to be in use."  If I press the "Take Ownership" button, it immediately returns with a dialog box indicating "Taking ownership of this virtual machine failed."

So after doing some digging around the internet it turns out the solution is pretty simple. First shut down VMware Workstation then go and have a look at the folders where all the virtual machines are stored. In that folder we should see some .lck or .lock files and/or folders. Whether its .lck or .lock, it depends on the version of your VMware product. Delete those files (move them to another folder if you are more comfortable with that) and then go back to VMware Player / Workstation. Open those virtual machines again and now they will work as they used to be.

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Go lang Println vs Print vs Printf

Earlier today, I was picking up a new programming language, Go. Go is an open source programming language that makes it easy to build simple, reliable, and efficient software. In Go, there is an included package named “fmt”. Fmt has lots of built-in functions. For now let’s look at fmt’s printing.

Println. Let us begin with the Println method. This method is one of the easiest and simplest ones in fmt. We first must use an import statement with the argument “fmt”. Println is versatile and can accept many arguments.

Source:

package main import "fmt" func main() {    // The Println method can handle one or more arguments.    fmt.Println("cat")    fmt.Println("cat", 900)    // Use Println on a slice.    items := []int{10, 20, 30}    fmt.Println(items) }

Output:

cat cat 900 [10 20 30]

Print, for-loop. The Println always inserts a newline after we use it. But Print does not. It just writes the data to the console with no trailing newline.

Source:

package main import "fmt" func main() {    elements := []int{999, 99, 9}    // Loop over the int slice and Print its elements.    // ... No newline is inserted after Print.    for i := 0; i < len(elements); i++ { fmt.Print(elements[i] + 1) fmt.Print(" ")    }    fmt.Println("... DONE!") }

Output:

1000 100 10 ... DONE!

Printf. This method accepts a format string. We use codes like “%s” and “%d” in this string to indicate insertion points for values. Those values are also passed as arguments.

Source:

package main import "fmt" func main() {    name := "Mittens"    weight := 12    // Use %s to mean string.    // ... Use an explicit newline.    fmt.Printf("The cat is named %s.\n", name)    // Use %d to mean integer.    fmt.Printf("Its weight is %d.\n", weight) } Output: The cat is named Mittens. Its weight is 12.  

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Install LaTeX on Ubuntu or Debian

LaTeX is a document markup language and a text preparation system to create documents. LaTeX is recommended to create technical or scientific articles, papers, reports, books and other documents like thesis.

1. OPEN YOUR TERMINAL

A terminal is a Command Line Interface (CLI) where you type commands to tell the computer what to do. Make sure you've opened the terminal, if so, continues in the next step.

2. INSTALL TEX LIVE

TeX Live is a TeX distribution to get up and running with the TeX document production system. To install it, once you're in the terminal, enter the following command:

sudo apt-get install texlive

This operation may take a long time because there is a lot of files.

3. INSTALL TEXSTUDIO

Now you need a text editor. I recommend using a specific editor for LaTeX. There are many text editors for LaTeX on the Internet as Kile, TeXworks, JLatexEditor, Gedit LaTeX Plugin, etc. My favorite text editor for Latex is TeXstudio. TeXstudio is a cross-platform open source LaTeX editor. To install it, go to the Ubuntu or Debian terminal and enter the following command or download from Ubuntu Software Center:

sudo apt-get install texstudio

In a few minutes you'll have installed TeXstudio.

4. CREATE YOUR FIRST DOCUMENT

To check that everything is working properly, create a LaTeX blank document. Open TeXstudio and click on File, New. Then write the following code:

\documentclass{article}

\begin{document}

     Hello, world!

\end{document}

Now save the document as a 'tex' file going to File, Save. Finally, compile the document. And that's it! You've created your first LaTeX document!

[hilaryhojiahao]

Python: Unable to find vcvarsall.bat

I’m sure many beginners using python will face the problem “Unable to find vcvarsall.bat” when run “pip install” for certain packages in clean windows. What beginners like me will do next is seeking Mr. Google or Ms. Yahoo for help and usually ended at Stackoverflow with a long tread telling you in details what went wrong and you need something like Microsoft Visual C++ 2013 Redistributable or MingW.

Frankly speaking usually these methods is tedious and might ended up not working especially for newbie programmers. As a newbie programmer myself, I would recommend download Visual Studio Community 2013, it is free for personal and use of small teams of developers. What are you waiting for, go download the compiler and you can run pip install everything packages smoothly by now.

[hilaryhojiahao]

Python Maketrans() Function

Easy Caesar Cypher encrypt and decrypt using maketrans function in python 2 and 3. 

Below are simple example of using maketrans in Python 2. You need to import the library before using the function. If you are using Python 3, just omit the import step. It will give you the same output.

from string import maketrans

def trans(a):    alphabet = "abcdefghijklmnopqrstuvwxyz"    key = "cdefghijklmnopqrstuvwxyzab"    translator = maketrans(alphabet, key)    return a.translate(translator)

[hilaryhojiahao]

Text Editor for Developers

Earlier this week, my PC just arrived from ASUS. First thing we developers usually do is remove and installing all the software we need. Since its a new laptop, I would like to try a new text editor over the ones that I’ve been using for years. Therefore, Atom text editor created by Github was chosen. The download size is around 76mb. So with a 1mbps connection it will take you approximately around 7-9 minutes to finish the download. Since there are lots of features in Atom, installation might take a few minutes.

My review as an amateur developer. First like Sublime Text 2, Atom allows installing various packages and themes developed by fans and kind people to facilitate development. You can create your own code snippet and reused them for development. Shortkeys are very important for developer. Every page of files that we wrote we use shortkeys to save time. Atom comes with a wide range of shortkeys with many combination (more than half to the combination I couldn’t remember). If you do not like those default shortkeys you can always modified them in the settings.

The next thing I want to blog about Atom is the developer features. If you have been using Chrome developer tools to work on your project, I can bet you will fall in love with Atom first sight. Github engineers has a full version of chrome developer tools built into Atom. Amazing isn’t it?

The last big thing about Atom is git features. Since Atom is engineered and designed by Github, it will not be complete without the having Git function and features built-in. You can now commit your codes, watch the difference when you change codes, which current branch you are working and etc using Atom.

So that’s all my review for now. Go give it a try.

[hilaryhojiahao]

#Day 6 Django Side Project

I’m not sure should I use Day 6 or should I start again from Day 1 to document about my side project. Whatever! So today, I start to pick up where I left off. I’ve stalled the development of Django forms and worked on the frontend of the app. Found a good MVP framework called ReactJS. Few reason I chose ReactJS over RiotJS or AngularJS. First JSX compiler in ReactJS is fast. With my amateur skill I hope make the webapp as responsive as native app with lesser code. Next reason is embedding ReactJS into Django is painless especially when you have used AngularJS for the past year. Last but not least, it is because ReactJS is developed by Facebook and heavily implementing with lots of support (this is good stuff). I too finalize the app with the name healthhacks. What can this app do? I hope to reveal the answer in coming two months time. For now I can only say it will be as sweet as the candy name “Hacks”. Just stay tuned.

[hilaryhojiahao]

Set Ubuntu 15.04 Application Menus

Earlier this morning I’ve made an upgrade to my Ubuntu. From v14.10 to 15.04. There are couple of tweaks done right by the Canonical Team including a kernel update, faster booting time and animation speed tweaks. Of all their new features, the one I love most is now Ubuntu application menus can now be set to ‘Always Show’. The problem is this features does not come by default.

To use this feature, one must have dconf-Editor installed. If you don’t have it yet, you can grab it at Ubuntu Software Center. Its free of charge!! After the installation, fired up dconf-Editor. To set the application menus you just need to expand com > expand canonical > click on unity > check always-show-menus.

Now your application menus will show no matter where your cursor is.

[hilaryhojiahao]

Painless Eclipse Luna Installation for Ubuntu 14.10

I have tried multiple times to update Eclipse 3.8 provided by Ubuntu Software Center using different working packages but in vain. Dependencies conflicts during update and upgrade almost got me pull off all my hairs. After an hour later, I gave up and start to install Eclipse Luna manually. Below is how I did it painlessly in 5 easy steps.

Download Eclipse Luna from here. Choose the package that matches the language that you are going to develop.

Start terminal by using ctrl + alt + T. Navigate to the directory that you have downloaded the Eclipse file. Run the command tar -xf eclipse-luna.tar.gz to decompress the tar file. This will create an Eclipse directory.

For convenience, move the directory to your /usr/bin directory. I like to keep my binaries and programs in this directory. To move use the command sudo mv eclipse /usr/bin/eclipse.

Create a symbolic link for Eclipse executable by using sudo ln -s /usr/bin/eclipse/eclipse /usr/bin/eclipse.

For convenience, add a Dash entry for Eclipse. Bring up your terminal again and run cd  /usr/share/applications/ and create a eclipse.desktop file using your favorite text editor. I prefer using vi/vim (root access is require), so sudo vim eclipse.desktop and enter the following content:

[Desktop Entry]

Name=Eclipse

Comment=IDE

Exec=/usr/bin/eclipse

Icon=/usr/bin/eclipse/icon.xpm

Terminal=false

Type=Application

Categories=Development;

Now fired up your Unity dashboard and you should see Eclipse Luna icon. You can even pin the icon on your taskbar.

[hilaryhojiahao]

#Day 5 Django Side Project

This might be the worse side project that I ever encounter. Don’t misunderstood, its not about Django framework or the documentation. Its because of the timeline. Everything in my life this week is too packed up that I cannot even finish working Django forms for a single app in a Django project. Will have to leave for meeting for now. Hopefully everything will be in working order after the meeting. I hate delaying my work on the small bit of project. See you again tomorrow on Django forms review.

[hilaryhojiahao]

Day 4 Django Side Project

So I’m still working halfway with Django Forms due to meetings and brushing up for my master’s thesis. Seriously I need to learn how to multitask by handling multiple project simultaneously. Hopefully I can get the gist of Django forms by tonight.

[hilaryhojiahao]

Day 3 Django Side Project

Yesterday was a pretty busy day. I only manage to spend couple of hours working on Django forms. Still prefecting the gist, thus nothing much I can comment at the moment. Since today is weekend, I’ll be working full force on the system and prefect the usage of Django forms. Stay tune for more updates.

[hilaryhojiahao]

Day 2 Django Side Project

So yesterday I spent the whole day working with models and admin on Django. There are lots of sneaky stuff about Django admin. First off, it saves backend developers time because it has a design. Secondly, developers are free to customize the list of stuff in the Django’s ready-made admin by using the fieldsets feature. Filters and display list are some other features available. If you want to know more, hop to the Django Project page. They have more extensive description on their tutorials and documentation. Done with part one of models and admin. What am I going to do today?

Well today I’m going to work on Django’s form. Django comes with some neat form handling functionality, making it a pretty straightforward process to gather information from users and send it back to your web application. One of the major advantages of using Django’s forms functionality is that it can save you a lot of time and HTML hassle. According to Django’s documentation on forms, the form handling functionality allows you to:

display an HTML form with automatically generated form widgets (like a text field or date picker);

check submitted data against a set of validation rules;

redisplay a form in case of validation errors; and

convert submitted form data to the relevant Python data types.

That’s all I wanted to document for now. I’ll start working on forms now and give everyone of you a nice feedback tomorrow.

[hilaryhojiahao]

Most Recent Work

Its been a while since I last dusted my blog. I think its almost the time for me to post some of my latest work. For those who are reading it, you must be wondering since you have been programming for such a long time, why only now you start documenting your progress. Answer is pretty simple, I’m picking up a new framework (not so new) and working on a project based on this framework. So I’m setting up this thread to walk myself and see how fast I can grow.

This is web development framework design for perfectionist with deadlines. If you have seen this motto, then you should know by now what framework I have been meddling around for my new side project. Yes, its Django! Django has been widely used by many developers worldwide for many years. I have been reading about this framework for 2 years and working on small projects for such as blogs, single page app and sending patching to MDN. I don’t have the time to start with any of the projects until now. Thanks to my mentor finally we are working something awesome based on Django for the Python community. What are we working on? Sorry we cannot let you know at the moment.

Now let me write about my progress, setting up the require tools is essential for a productive work. I’ve been using sublime text editor integrated with packages such as jshint, django and git. Next to run Django, I’m using Python 3 with virtualenv installed on system wide. All my projects will be running inside virtualenv to avoid polluting the base version of my Python software. After activating virtualenv, Django is being installed using pip. Besides Django, I’ve also made a pip install on ipython, pymongo and uWSGI. Let me document what I have worked so far. I have created a views using the powerful inheritance method for the homepage, about, privacy and a couple of basic pages. I have also written some models and admin.py stuff for this app. Based on our initial calculation everything is on schedule.

That’s all for the moment. Will continue to update my project progress tomorrow.

[hilaryhojiahao]

Ported vintage PS1 Crash Team Racing on PC. (at 575, Jalan Raja Muda)

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Everytime I code, this is the list of songs I use. Productive for most of the time.

[hilaryhojiahao]

Moztalk UNIMAS

The first Mozilla event was being held in Universiti Malaysia Sarawak (UNIMAS) on 17th and 20th December 2013. Theme of the event is Mozilla, HTML5 and Its Hidden Potential. The event kicked off with a keynote session about Mozilla, its manifesto, products and some coming soon technologies. The keynote session was deliver based on the information provided by Soumya Deb. The presentation slides are hosted at talks.hilaryjhho.com. The keynote session lasted for 45 minutes.

After the keynote session, the participants took a 15 minutes break. During break time, lunch packs filled with swags were distributed by Mozilla volunteers to the participants. Lunch and swags were sponsored by Mozilla Foundation.

Due to time constraint, the participants for the event have their lunch while the breakout sessions commence. Each breakout session takes a duration approximately 30 minutes. Below are the full list of speakers and their session titles:

Untold Stories of HTML5 — Allyson Wong

Collaboration using Togetherjs — Cecelia John

Contribute to Mozilla Codebase using DVCS — Lee Hong Yew

Rapid App Development using Appmaker — Amanda Fong & Kok Weiying

SuMo and Firefox Student Ambassador Recruitment — Donald Stephen & Phoebe Francis

At the end of the event, participants ended with a deeper knowledge on HTML 5 and the open source. A few participants showed their interest in Mozilla's project and signed up to be a volunteer. The overall of the event was a great success. Special thanks to Katherine Naszradi, Konstantina Papadea, William Quiviger, David Walsh, Rosana Ardilla and last but not least my mentor Eusebio Barrun Jr. for all the support.

Below are some photos taken in the event. For full album please browse to my Facebook photo album.