Read Error in LibreOffice

If you cannot open the LibreOffice document due to read error as the picture below

Un-install LibreOffice version 3.4 and install LibreOffice 3.5 will solve the problem. I got this problem when saved a file in LibreOffice 3.5 in Mac and attemped to open it in Ubuntu.

Ruby and Ruby on Rails Resources

Ruby Programming Language is a dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write. Ruby was first designed and developed by Yukihiro Matsumoto (a.k.a. Matz), a Japanese computer scientist and software programmer, in the mid-1990s in Japan.

Ruby on Rails (RoR) is an open-source web framework using Ruby programming language. Ruby on Rails released as open source by David Heinemeier Hansson, Danish programmer, in July 2004. Like many web frameworks, Ruby on Rails uses a variant of the Model/View/Controller (MVC) architecture pattern to organize application programming. As of March, 2012, there are more than 200,000 sites using Ruby on Rails per BuiltWith.com

Programming Ruby: The Pragmatic Programmer's Guide

Ruby in Twenty Minutes

Coursera.org: Software Engineering for Software as a Service

Stanford Open Class Room: Web Application

RubyGems.org is the Ruby community's gem hosting service.

RubyForge is a home for open source Ruby projects

The Pragmatic Bookshelf | Learn to Program

Learn Code The Hard Way

Ruby Tutorials for Beginners

http://rubylearning.com/

RubyMonk - Interactive ruby tutorials to learn Ruby

Rails 3 screencasts

Free episodes from RailsCasts.com

Ruby Koans

Automatically Show and Hide Dock Bar on MacBook Pro

By default, the dock bar always show on MacBook Pro. It consume a lot of space on screen. To make it automatically hide and show:

1. Right click the middle space between icon, go to dock preferences.

2. Check automatically hide and show the Dock

or
Click on the Apple icon on the top left screen to access Dock preferences

or really quick: Press <option><command><command>D keys at the same time to turn on/off the automatically hide and show the Dock

How to Open Two Excel Files Side by Side in Two Monitors?

The best solution is using LibreOffice. With LibreOffice Calc, you can open one Excel spreadsheet in one monitor and another speadsheet in other monitor to compare, view or edit.

Change the configuration in Excel 2007 or 2010 is another solution by check the check box 'Ignore other application that use Dynamic Data Exchange'. You may encounter with the run-time error when you attempt to close or open again.

References:

• http://www.lytebyte.com/2008/05/13/how-to-open-two-excel-files-side-by-side-in-separate-monitors
• http://social.technet.microsoft.com/Forums/en-US/w7itproinstall/thread/6ba32569-19a0-4b45-806f-9a42258bdb5f

Troubleshoot Internet Connection

1. Make sure you can connect to your router by ping to your router IP (for example: 192.168.1.1) from command line (Windows) or terminal (Mac or Linux) or access to the router web page using the browser. If you cannot ping or see the router web page, check your network configuration on your computer.
2. Are you using the wireless? If yes, connect the CAT 5 Ethernet cable connect to your computer.
3. Is the wired connection working? If yes, your wireless has issue.
4. If the wired connection is not working, is other computer in your home, your office or your LAN can access to the Internet? If just only your computer, check your network configuration.
5. If all computers in your LAN could not access to the Internet, power down both the router and cable modem.
6. Wait for 15 seconds, and turn them on.
7. If you still not connect, check to see there is outage in your area. If not, verify your router is working.
8. To verify your router is in good condition, hook up another spare router or your computer directly to the cable modem. Note: If you hook up your computer directly to the cable modem, make sure the firewall on computer enable and all ports other than 80 are closed. Connect computer with open ports: 20, 21, 139, 3389 directly to cable modem or Internet is dangerous and not recommend. Here, I'm using my test computer running GNU Linux with all closed ports to connect directly to the router.
9. If you can connect to the Internet without router or with another router for an hour or more, your existing router is bad. It need a replacement.
10. If you cannot connect to the internet, chance is your cable modem or the link from cable modem to your internet service provider have issue, call your internet service provide technical support.

Delete Facebook Message

How many clicks to use to delete a Facebook message?
1. Click on Action
2. Click on Delete Message
3. Click on Delete All button
4. Click on Delete Conversation button

and to delete a regular email: one click. Which one is easy?

How to mount a VirtualBox shared folder in Ubuntu guest

1. Click on VirtualBox VM Devices and Shared Folders... to create a shared folder, named it SharedFolder, for example.
2. On Ubuntu guest machine, open Terminal
3. Type sudo mkdir /mount/vboxshared
4. Type sudo mount -t vboxsf SharedFolder /media/vboxshared to mount the VirtualBox shared folder as read. To make it read/write, use this command: sudo mount -t vboxsf -o uid=1000,gid=1000 SharedFolder /media/vboxshared

If the shared folder is a permanent share and auto mount, make sure your user id in group vboxsf. To add a user id to group vboxsf, using command: sudo usermod -a -G vboxsf linuxuserid

Reference:

https://help.ubuntu.com/community/VirtualBox/SharedFolders
https://forums.virtualbox.org/viewtopic.php?t=3201&amp;highlight=share+folder