Archive for February, 2013
Ubuntu on Dell Inspiron 15 3520 laptop log
Today I’ve got my Dell Inspiron 3520 laptop with pre-installed Ubuntu Linux. This article contains the log, notes and tips about Ubuntu and this laptop.
Shortly about the hardware configuration:
15.6″ (1366×768) LED / Intel Pentium B960 (2.2 ???) / RAM 4 ?? / HDD 500 ?? / Intel HD Graphics / DVD+/-RW / LAN / Wi-Fi / Bluetooth / Camera / Ubuntu Linux 11.10 (Oneiric Ocelot)
Dell says that for this laptop.
Also, before I bought it the list of Ubuntu’s certified hardware had been checked against this notebook. I found out that this laptop is a certified hardware of Ubuntu but it should have pre-installed Ubuntu only.
After starting the laptop, Ubuntu asked some data about me, what city I am, default login/password, etc. Then I have a working operating system out of the box. I like it!
Then I decided to install some updates. To my surprise, there were lots of updates! 20 minutes of updating the system.
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sudo apt-get update sudo apt-get upgrade |
It’s very interesting for me is it possible to upgrade from 11.10 to Ubuntu 12.04 keeping all the drivers for the laptop. Think, I’ll test this later 
The next step, is installing the Chromium form the Ubuntu Software Center. Everything is OK.
Then I needed something like Google Talk on Windows but for Linux. Unfortunately, there isn’t an analog of Google Talk for Linux 
But there’re some chat clients that can work almost like Google Talk. I use Empathy Internet Messaging that comes with Ubuntu.
What about hardware, it works good except of fan. The fan is too loud. I’m going to investigate this problem. I have some links where the similar fan problem mentioned:
Ubuntu heating my laptop
Ubuntu noisier than Windows 7
Fan keeps running indefinitely on Ubuntu after system was temporarily hot
February 23
Today I installed Skype form the Ubuntu Software Center. I logged in without any problems. The look of Skype differs from Windows Skype but it works and there isn’t any ads!
Yesterday, I installed Chromium web browser and logged in with my Google account. Today, when I worked with Chromium surprisingly it installed all the browser extensions I have on Windows. All this happened without restarting a browser.
February 28
I’ve just installed DropBox and there’re some my video files in 3gp format. Ubuntu has just downloaded and installed corresponding codecs for watching the video of this format when I clicked to open the video file!
It isn’t the end! I’m going to continue this log.
How to center an image horizontally in CSS
It’s possible to center some text in the paragraph by using text-align CSS property. Also, you aren’t limited only by the paragraph, it’s possible to center the text inside any other container, for example, inside div, h1, blockquote etc. Just set text-align property to center and you’ll get the text centered.
Fortunately, you can use such approach for images to align them by center, also! Just set text-align with a center value for the image’s parent element and you’ll get it centered horizontally.
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<div class="image-container"> <img src="image.png"> </div> |
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.image-container { text-align: center; } .image-container img { display: inline-block; } |
Notice that you cannot align an image by center if you’re using float property with left or right values for the image. Also, text-align property doesn’t take an affect if the image has display other then inline or inline-block which is a default display for images in the most of browsers.
Try it here http://codepen.io/starikovs/pen/iqxms.
By the way, to center an image vertically you can use the described in the article vertical align block element inside block element.
CSS background transparency
This note is about applying a transparency or opacity for background in CSS. Notice, that it isn’t possible to set the transparency for background property specifying it in the property definition. So, you need to use some CSS trick to achieve you want.
My way to apply opacity for background:
1. Create new z-index context for the element with the background. This is a container element.
2. Add :before pseudo element for that container element. It will have a background layer with opacity property.
3. :before element should be pozitioned under any other elements in the container element. So, set z-index “-1″ for it.
4. Set a background for the :before element and stretch it to the container element.
I think that’s all. Here’s the code snippets:
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<div class="container"> <p>Lorem ipsum dolor sit amet..</p> </div> |
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.container { position: relative; z-index: 0; } .container:before { background: url(bg.png); position: absolute; bottom: 0; content: ' '; left: 0; opacity: .5; right: 0; top: 0; z-index: -1; } |
Try it here http://codepen.io/starikovs/pen/zGugk.
Fallback for background-color for old browsers
Unfortunately, I haven’t been used the fallbacks yet. I’ve just found out that some of rgba colors in IE8 are just transparent. This note is about the fallbacks for old browsers. When you’re using such features like rgba colors don’t forget about the fallbacks. In CSS, first you should write the fallback color for old browsers and then your rgba color. Here’s an example:
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.test { background: #000; /* fallback */ background: rgba(0, 0, 0, .8); } |
So, if the browser doesn’t understand rgba color it won’t apply it but apply the background-color above that it understands. The fallback should have rgb or hex values because old browsers understand them.
I test it on IE8.
Try it here http://codepen.io/starikovs/pen/omiCk.
Backup and restore MySQL database
This note is about how to create a backup of MySQL database with help of command line tools and then how to restore it on the server.
So, the first step is making a dump of the DB. For that task we use mysqldump command. Here’s the code:
mysqldump -h localhost -u root mydatabase > mydatabasebackup.sql |
After dumping we will have SQL file that contains SQL command to recreate a database structure and SQL commands to restore all the data.
To restore a database out of backup we should use mysql command. It should be like in the following example:
mysql -h localhost -u root -p -D mydatabase < mydatabasebackup.sql |
It will ask you for the password.
By the way, before restoring your database you should create it in case that the database doesn’t exist.
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mysql -h localhost -u root -p > create database mydatabase; |