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[3 May 2015 | No Comment | ]
How to Convert an ePub to Mobi Format

Kindle is an e-book reader designed and developed by Amazon.com. Many e-books you see on the Internet store their files in the EPUB file format. Kindle devices store their e-books in a MOBI file format. Unfortunately, Kindle cannot read files in the EPUB file format.

Hardware, Linux »

[9 Apr 2015 | No Comment | ]
Add WiFi to the Raspberry Pi

The Raspberry Pi comes with a 10/100 Ethernet Port to connect to the Internet. In most instances, this works fine. If you set up your Raspberry Pi as a Media Center, your Wi-Fi router and your A/V Receiver might not be in the same room. Running a long Ethernet cable from your Wi-Fi router in one room to your Raspberry Pi in another room does not seem like a practical solution.

Hardware, Linux »

[7 Apr 2015 | No Comment | ]
What is a Raspberry Pi?

What is a Raspberry Pi? Is it edible like a pie? Is it sweet? Is it food? If you are looking for a cooking class, this is not the place.

Linux »

[9 Mar 2015 | No Comment | ]
Find Files in a Directory

Suppose you have several directories with several sub-directories with files in them. How do you go about finding the files you need? You may want to find the latest modified files. You may want to find files belonging to a certain group. You may want to find files under the dotfiles directories. The list goes on and on.

Hardware, Linux, Macintosh, Web, Windows »

[6 Jan 2015 | No Comment | ]
Wireless Issues with Motorola SBG6580 Cable Modem

If your Internet Service Provider (ISP) is Time Warner Cable (TWC), you have the option to either lease the cable modem or buy your own. If you buy your own modem, you can save $5.99 per month in monthly fees. However, you need to buy a modem that is approved by TWC. There are many modems on their approved list.

Linux »

[4 Nov 2013 | No Comment | ]
Search for a string in a directory of files

Suppose you have a string that you want to search in a directory. How would you do it? What if this directory contains many files and sub-directories? What if you want to search the string in a particular set of files?

Linux »

[30 Jun 2013 | No Comment | ]
Read from a standard input and write to a standard file

In golf, a tee is a stand used to support a stationary golf ball so that a player can strike it. In Unix, a tee is a program used to read a standard input and write to a standard output and file.

Linux »

[19 May 2012 | No Comment | ]
Ubuntu Blank Screen on Boot

Have you ever installed Ubuntu, rebooted and then got a blank screen? It does not mean Ubuntu has crashed on you. This has happened to me on version 10 and 11 of Ubuntu. It appears Ubuntu does not have video drivers for certain video adapters such as Nvidia cards.

Linux, Macintosh, Windows »

[10 Jul 2011 | No Comment | ]
Send a Test Mail Using Telnet

When you are having a problem sending a mail message, the first thing you want to do is test the SMTP (Simple Mail Transfer Protocol) connectivity. By default, SMTP listens on port 25. By using telnet, you can connect to port 25 on the mail server and test whether or not you can send a message. This step is done on your own workstation. If you are having a problem sending mail from a web form, run this step from the server that is storing the web form.

Linux »

[19 Jun 2011 | No Comment | ]
What does

If you work with Unix systems, you may come across some strange commands such as numbers with greater than sign and ampersand. To the untrained viewer, these commands may appear gibberish, but in reality they do mean something meaningful. Their compactness brings about the elegance and beauty of Unix.
When I first saw the command such as the following in a crontab file, I was confused. I did not know what to make of it. Documentation for this command was very limited and required a lot of digging around to uncover what …

Database, Linux »

[8 May 2011 | No Comment | ]
How to Change or Set the MySQL Root Password

When you are setting up a database, it comes standard with the sa account that has access to everything. Unless you want to get comprised, you should change it to a difficult password. On some databases such as mySQL, the sa account is called root and it has a blank password.

Linux »

[25 Apr 2011 | No Comment | ]
What is /dev/shm and what is it used for?

/dev/shm is shared memory. It is offered in Linux as a way for memory to be accessed simultaneously by multiple programs.

shm is also known as tempfs or temporary file storage. On Linux it will appear as a mounted file system that you can access directly. Instead of writing to a permanent storage device such as your hard drive, it writes to virtual memory (i.e., it lives in RAM). Since it is memory, anything written to this file system will be removed the next time you reboot.

Linux, Macintosh, Web, Windows »

[10 Apr 2011 | No Comment | ]
OSI Model Layer

The Open Systems Interconnection model (OSI model) by developed by the International Organization for Standardization (ISO) in 1984. OSI reference model is a way of sub-diving network communication and grouping them into logical layers. On each layer, an instance provides the services the instances to the layer above it and requests services to the layer below it.

Featured, Linux »

[27 Mar 2011 | No Comment | ]
Find and Replace with SED

The power of search and replace is prevalent all over Linux. Whether you are using a text editor or on the command line, regular expressions come in handy.

When you are using a text editor such as vi, you are probably familiar with the search and replace feature. From the command line, the find and replace feature is also available if you use sed.

Linux »

[20 Mar 2011 | No Comment | ]
Boot to single user mode in Ubuntu 10.04 Lucid Lynx

There are occasions when the single user mode comes in handy. Take for example last week. I was messing around with iptables and I added to much restriction on my deny rules. As such, I could not log in to the network and get myself authenticated.
At first, it was very disheartening to find out that you locked yourself out of your own system. On the other hand, it becomes a challenge and you find it a valuable experience. What you find is that whatever you may have done with your …