Doce Ut Discas

Highlight a linked list item in blogger

2011-09-04T13:06:00.000-07:00

What i will show you here is the result found in this website: http://www.syndesmosnikiforos.gr/p/blog-page_9205.html

The site is in Greek but you can easily see the result if you click any one of the bullets in the main area of the page.

As you see when a link is clicked the same link is highlighted on the right menu. Also the right menu has a mouse over event that works fine. The best thing is that the component on the right is a standard link list that is added from bloggers Layout menu.

The first thing that you want to do is add a linked list in your blogger site.

This is done under the menu Layout, Add a gadget, and then select the Link List.

After the list is added go to Template menu and back up your template.

In the new blogger interface this is done by the Manage button located on the top right section of the page.

Next click the Edit HTML button and on the top check Expand Widget Templates.
Somewhere in the code displayed you will find some lines like these:

1: <b:widget id='LinkList2' locked='false' title='test' type='LinkList'>
2: <b:includable id='main'>
3: <b:if cond='data:title'><h2><data:title/></h2></b:if>
4: <div class='widget-content'>
5: <ul>
6: <b:loop values='data:links' var='link'>
7: <li><a expr:href='data:link.target'><data:link.name/></a></li>
8: </b:loop>
9: </ul>
10: <b:include name='quickedit'/>
11: </div>
12:</b:includable>
13:</b:widget>

TIP: You can easily find the section by searching for the title that you put when inserting the linked list.

The first change is to put an id on the ul tag in order to be able to customize it from CSS.
So line 5 will look something like:

<ul id='my_menu_right'>

Now we go to the main change that is needed. We have to replace line 7 with an if clause saying that when the pages url is the same as the links url then the class if the li element will change.
This is done with the following code (replace line 7):

<b:if cond='data:blog.url==data:link.target'>
<li class='selected'><a expr:href='data:link.target'><data:link.name/></a></li>
<b:else/>
<li><a expr:href='data:link.target'><data:link.name/></a></li>
</b:if>

The last part is to add the desired CSS styling to our blog.
Go to the Template menu and click the customize button. This opens the Blogger Template Designer.
From there click the Advanced menu,scroll down and click Add CSS. There put whatever styling you wish for the selected item, mouse over and the links style (This will overwrite any global settings set for links).
Before i uploaded the CSS code i tested it on Dreamweaver. I suggest that you test it somewhere first because it is a lot easier to locate any problems. Also i have put the comments so i can locate my code in the html template code witch as you saw earlier is really large.
The CSS code that i wrote is:

@charset "utf-8";
/* My CSS part Marios*/
ul#my_menu_right, ul#my_menu_right ul
{
margin: 0px;
padding: 3px;
list-style-type: none;
background-color: #c2d8fa;
-moz-border-radius: 10px; /* Firefox */
-webkit-border-radius: 10px; /* Safari, Chrome */
border-radius: 10px; /* CSS3 */
}
ul#my_menu_right li, ul#my_menu_right li a
{
color: #666666; padding: 5px;
margin: 5px;
font-weight:bold;
}
ul#my_menu_right li:hover,ul#my_menu_right li:hover a
{
color: #ffffff;
background-color: #4eabff;
-moz-border-radius: 10px; /* Firefox */
-webkit-border-radius: 10px; /* Safari, Chrome */
border-radius: 10px; /* CSS3 */
}
ul#my_menu_right .selected, ul#my_menu_right .selected a
{
color: #ffffff;
background-color: #4eabff;
-moz-border-radius: 10px; /* Firefox */
-webkit-border-radius: 10px; /* Safari, Chrome */
border-radius: 10px; /* CSS3 */
}
/* END my css */

Red5 freezes when running without error

2011-06-27T09:57:00.000-07:00

When i tried to run Red5 server the excecution froze without producing any errors.
The last two lines printed were:

[INFO] [Launcher:/installer] org.red5.server.service.Installer - Installer service created
Logger context selector method found

After that i tried to run the server from the eclipse plugin but the same problem occurred. After waiting the following error was produced:

Server Red5 Server Runtime at localhost was unable to start within 120 seconds. If the server requires more time, try increasing the timeout in the server editor.

The solution is not related to the eclipse plugin but it relies on the port number that you entered during the setup of red5. The default port number is 5080 and it works fine with that port. During the setup i did not know what the default port number was so that was the problem.

Red5 error exception BasicMDCAdapter

2011-06-27T09:48:00.000-07:00

After installing Red5 1.0 RC1 when i tried to run the server i got the following error:

Exception java.lang.ClassCastException: org.slf4j.helpers.BasicMDCAdapter cannot be cast to ch.qos.logback.classic.util.LogbackMDCAdapter

This error is produced because there are 2 additional jars that shouldnt be there.
The solution is to delete the following files from red5/lib directory

com.springsource.slf4j.juli-1.6.1.jar
com.springsource.slf4j.log4j-1.6.1.jar

More information ca br found: http://code.google.com/p/red5/issues/detail?id=43

How to install the same programs from a pc to another

2011-04-11T07:58:00.000-07:00

$ dpkg --get-selections > installed_progs
# cat installed_progs | dpkg --set-selections

How to reload ~/.bashrc

2011-04-11T07:57:00.000-07:00

0. Descritpion
Assume you change ~/.bashrc (eg you add a new alias or you extend the PATH variable)
or any configuration files. How do you update Bash without logging out and logging in?

1. How?

$ source ~/.bashrc

Eclipse deploy project libraries on glassfish

2011-02-08T06:25:00.000-08:00

On eclipse i had this weired problem:
I was able to start glassfish server but any project i tried to deploy was could not access the libraries i had imported in the project.

Lets start with glassfish installation in eclipse.

I am using Eclipse Helios and glassfish 3.0.1

On eclipse go to window->preferences
On the left select server->Runtime Environments and click on add.. button.

Then from the popup window on top left select Download additional server adapters
From the list select to install Glassfish.

Then choose the jdk you want to use and the installation folder of the server (glassfish has to be downloaded and installed manually)
Then finish the operation.

Now if you have some jars imported to your project when you deploy your project the referenced libraries are not by default published to WEB-INF/lib directory of your project.

The directory is located in glassfish-3.0.1\glassfish\domains\domain1\eclipseApps

Not in order to use the libraries you must right click on your eclipse project and select properties.
Then from the left select Deployment Assembly.
Click add and select Java Build path entries

Now your application should be correctly deployed

C segmentation fault in linux but working in windows

2010-12-14T05:27:00.000-08:00

Recently i came across an unusual problem.
I wrote a program in C on a windows machine using Dev-C++ program. The program compiled and run successfully. When i tried to compile it on linux using gcc it compiled successfully but when running it produced a segmentation fault!

The error was in the use of atoi() and strtok.
I had a string in the form "10 20 30" and i wanted to split it using the space character and the convert the numbers to intergers. In windows when strtok reached the end and returned NULL atoi returned 0.
But in linux atoi with a NULL input produced the segmentation fault.

So the solution is to create a temp variable of char type and check if it is null before assigning the value to an int.

int number;
char *temp_atoi;
temp_atoi=(char*)malloc(10*sizeof(char));
   while(temp_atoi)
   {
   number=atoi(temp_atoi);
   if( number>=0 )
   {
   //Do something
   }
   temp_atoi = strtok(NULL, " ");
   }

I hope this helps someone! I lost a lot of time finding it out!

Windows 7 - Can't pin any Folder to Windows Explorer in taskbar

2010-11-17T09:42:00.000-08:00

For a while i had this problem with windows 7. I dragged a folder i wanted to pin in windows explorer in taskbar but it did not show anything.This is the solution that worked for me.

One of your Delete or Clear Jumplist Recent Items in Windows 7 is corrupted in AutomaticDestinations-hidden system folder
go to
%APPDATA%\Microsoft\Windows\Recent\AutomaticDestinations

Delete the largest file or just delete them all.

The solution comes from a comment on this forum post : http://www.mydigitallife.info/2009/01/17/fix-unable-to-pin-app-to-taskbar-and-start-menu-missing-context-menu-and-jump-lists-error-in-windows-7/

Hope this helps!

toshiba nb200

2010-10-11T05:35:00.000-07:00

troubleshooting
===============
- slow start up:
http://napalmpiri.wordpress.com/2010/05/06/ubuntu-lucid-lynx-on-toshiba-nb-200-slowno-boot/

profile c++

2010-07-29T07:04:00.000-07:00

1. g++ -o foo foo.cpp -pg #compile with -pg
2. $ ./foo args #creates gmon.out
3. $ gprof gmon.out

javax.persistence.PersistenceException: No Persistence provider for EntityManager named

2010-05-19T07:23:00.000-07:00

troubleshooting error:
javax.persistence.PersistenceException: No Persistence provider for EntityManager named

persistence.xml should be in your CLASSPATH.

For eclipse web projects place persistence.xml in src/META-INF/persistence.xml
and eclipse will copy it into WebContent/classes/META-INF/persistence.xml

एनाबले tomcat autodeploy

2010-05-15T10:25:00.000-07:00

set autoDeploy to true in the conf/server.xml

flex - compiler options

2010-05-08T08:52:00.000-07:00

keep-generated-actionscript=true.............the keeps the generated actionscript from mxml in folder /generated

flex - access public properties or methods

2010-05-08T08:48:00.000-07:00

parentDocument

parentApplication

FlexGlobals.topLevelApplication

references

http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf61c8a-7fff.html

Show Run menu in Windows Vista and Windows 7

2010-02-24T11:19:00.000-08:00

Back in the days of Windows XP(Professional i do not know about home) Run... menu could be found in start menu. This changed in Windows Vista and was kept that way in Windows 7.
There are three ways to access the run command.

1. The first way is to press "windows key" and r on the keyboard. This will make the run menu appear.

2. The second way is to type run in the search field of the start menu.

3. And the third and last way i know is to add run in start menu. This can be done as follows:

Right click on start menu icon and select Properties.

From start menu tab click customize

From customize menu scroll down until you find Run command and check it. Then click OK

You are done! Now you should see the Run command dialog in start menu above the shutdown option.!

Shutdown command in windows

2010-02-24T10:39:00.000-08:00

Some time ago i wanted to leave my computer running for a short time only, not all night. I was looking for a way to do this without installing a new program in windows. All i wanted was to schedule the computer for shutdown after 15 minutes.

I started looking for an easy way to do this and preferably without installing another program. So i found out that windows command line has a built in command called shutdown.
This was all that i needed. Much easier and time saving than looking for an appropriate program, downloading and installing it. Also it is easy to use. Just open the run dialog from start menu (click here if you can not find it) and type:

shutdown /s /t 60

This means that the system will power of (/s argument) in 60 seconds (/t 60 argument). If you want more time just increase the number of seconds.
Now lets say that the time you entered is not enough. To abort the shutdown process just type:

shutdown /a

The command also has many other arguments. some of them are:

Argument	Meaning
/i	Display the graphical user interface (GUI). When used this must be the first option.
/t xxx	Set the time-out period before shutdown to xxx seconds. The valid range is 0-315360000 (10 years), with a default of 30.
/s	Shutdown
/l	Log off
/r	Shutdown and restart the computer.
/p	Turn off the local computer with no time-out or warning.
/h	Hibernate computer.

This command is available in:

Windows XP

Windows Vista

Windows 7

Cedega 7 install issue "cedega Error: Dependency is not satisfiable: python2.4-dbus"

2009-10-14T08:26:00.000-07:00

Today i downloaded the .deb version of cedega from this URL http://www.cedega.com/downloads/

When i tried to install cedega i came across the following error:
cedega Error: Dependency is not satisfiable: python2.4-dbus

After some search i found out that in ubuntu 9.04 (Jaunty) the package python2.4-dbus was renamed to python-dbus. So this leads to a broken dependency error. The solution i found is:

Open a terminal and navigate to the directory you downloaded the .deb file from cedega. Usally this is your home folder or Desktop folder.
Execute the following commands by the order they appear:

$ mkdir -p cedega_000133_all/DEBIAN
$ ar p cedega_000133_all.deb data.tar.gz | tar zx -C cedega_000133_all/
$ ar p cedega_000133_all.deb control.tar.gz | tar zx -C
$ cedega_000133_all/DEBIAN/
$ mv cedega_000133_all.deb cedega_000133_all.prerebuild.deb
$ perl -pi -e 's/python2.4-dbus/python-dbus/' cedega_000133_all/DEBIAN/control
$ dpkg-deb --build cedega_000133_all
$ rm -rf cedega_000133_all
$ sudo dpkg -i cedega_000133_all.deb

Make sure you have write permissions to this folder if it is outside your home directory. If you don't have sufficient write permissions the build command will produce an error.
Hope this helps.

Disable Hibernation in windows Vista

2009-05-18T10:42:00.000-07:00

If you have read the post about the hibernation problem in Vista you may also be interested in disabling Hibernation to save some space from your disc.

This can be done with two ways.

The first one is to excecute the Disc Cleanup utility and delete the file. In my opinion this has a major disadvantage. The Disc cleanup utility is realy slow and takes a considerable amount of time in order to calculate all the available data.

The second and much faster way is to go to the command line as you did in the previous post and write:

powercfg /hibernate off

When you want to enable it again just write:

powercfg /hibernate on

Left 4 Dead crashes on Vista [Solved]

2009-05-18T10:20:00.000-07:00

If you have played the game Left 4 Dead on windows Vista you may have noticed that on random times the game crashes with no obvious reason.
For this problem i hadn't found a valid solution for some time. The solution that worked for me is:

Step 1:
In the main menu screen of the game go to

Options -> Video
Click Advanced options and set the option multicore rendering to DISABLE

This solution did the trick for me. Before that i had tried all the options in Vistas compatibility mode but nothing worked.

Hibernation not working or isn't available in Windows Vista [Solved]

2009-05-18T09:35:00.000-07:00

WIndows Vista have the bad habbit of deleting the Hibernation file when you excecute the Disc Cleanup utility.
This utility can be found when you right click on a hard disc and select Properties. After you choose to clean this file you will not be able to put your computer in hibernation mode. Fortunatly there is a simple solution.

Step 1:
Go to: Start menu -> All programs -> Accessories
and right click on the Command Prompt.

Step 2:
Select the option Run as an Administrator and accept the UAC warnings.

Step 3:
In the comand line write:

powercfg /hibernate on

Mount iso file in Ubuntu

2008-10-27T05:30:00.000-07:00

This post will show you 4 ways to mount an iso file like a normal cd/dvd drive in Ubuntu. By using these you don't have to write the iso file to a cd or dvd. They are ordered from the easiest to the hardest.

Mount iso using Gmount-iso.
This is a great program that i found recently. To install it just type:

sudo apt-get install gmountiso

The best thing with this program is that you can mount the image anywhere you want. You can even mount it on the cdrom folder. (if you execute it with sudo )

sudo Gmount-iso

Mount iso using nautilus.

This is the easiest and fastest way i know.

Step: 1
With this way you only have to install a .deb package. This package is called nautilus-mount-image and it can be found
http://launchpadlibrarian.net/18219053/nautilus-mount-image_0.2.0-1_all.deb
or
https://edge.launchpad.net/%7Ezootropo/+archive/+files/nautilus-mount-image_0.2.0-1_all.deb

After installing the package when you right click on an iso file you will see the option to Mount.
The only problem that i found with this way is that you cannot mount it where you want (in a folder of your choise) .

Mount iso using nautilus scripts.

To make this way work you need to create two nautilus scripts and put them in the correct folder.

Step:1
Create a new file named mount in the folder ~/.gnome2/nautilus-scripts. This file will mount the image file you want.

gedit .gnome2/nautilus-scripts/mount.sh

and copy the following and save the file

#!/bin/bash

gksudo -u root -k /bin/echo "got r00t?"

sudo mkdir /media/"$*"

if sudo mount -o loop -t iso9660 "$*" /media/"$*"
then
if zenity --question --title "ISO Mounter" --text "$* Successfully Mounted.

Open Volume?"
then
nautilus /media/"$*" --no-desktop
fi
exit 0
else
sudo rmdir /media/"$*"
zenity --error --title "ISO Mounter" --text "Cannot mount $*!"
exit 1
fi

Step:2
Create a new file named unmount in the folder ~/.gnome2/nautilus-scripts. This file will unmount the image file you previously mounted.

gedit .gnome2/nautilus-scripts/unmount.sh

and copy the following and save the file

#!/bin/bash

for I in "$*"
do
foo=`gksudo -u root -k -m "enter your password for root terminal
access" /bin/echo "got r00t?"`

sudo umount "$I" && zenity --info --text "Successfully unmounted /media/$I/" && sudo rmdir "/media/$I/"
done
done
exit0

and copy the following and save the file

#!/bin/bash

gksudo -u root -k /bin/echo "got r00t?"

sudo mkdir /media/"$*"

if sudo mount -o loop -t iso9660 "$*" /media/"$*"
then
if zenity --question --title "ISO Mounter" --text "$* Successfully Mounted.

Open Volume?"
then
nautilus /media/"$*" --no-desktop
fi
exit 0
else
sudo rmdir /media/"$*"
zenity --error --title "ISO Mounter" --text "Cannot mount $*!"
exit 1
fi

Step:3
Now we just have to give execution rights to the files we created.

sudo chmod +x .gnome2/nautilus-scripts/mount.sh
sudo chmod +x .gnome2/nautilus-scripts/unmount.sh

The only problem that i found with this way is that you cannot mount it where you want (in a folder of your choise) .

If you want some more nautilus script visit:
http://mundogeek.net/nautilus-scripts/

Using loop Kernel Module

This is the hardest way but the only one if you don't want to use a graphical interface.

Step:1
The first thing you need to do is create the directory that the iso is going to be mounted.

sudo mkdir /media/image_folder

Step:2
Now you have to load the loop mode to your kernel:

sudo modprobe loop

Step:3
Now we can mount the image file (image_file.iso) to the folder we created.

sudo mount image_file.iso /media/image_folder/ -t iso9660 -o loop

Step:4
When we want to unmount the image file

sudo umount /media/image_folder/

Disable Xgl server

2008-10-24T04:47:00.000-07:00

This post will show you how to disable xgl server in Ubuntu. With this way it is no longer necessary to use any special X session to disable xgl server. I used this way because my laptop has an ati graphics card (Mobility Radeon X1700) and i had many problems with xgl server.

Step 1:
The only thing you need to do is create an empty file named disable in your home directory in the path ~/.config/xserver-xgl/

cd .config/xserver-xgl/

If the above path does not exist create it

mkdir .config/xserver-xgl/

Step 2:
Now to create an empty file named disable:

>disable

Now you just have to logout and when you login xgl server won't start.

Create an iso file from a cd,dvd or folder

2008-10-24T01:53:00.000-07:00

This post will show you how to create an iso file from a cd, dvd or a folder.

Create .iso from CD - DVD

Step 1:
Now we move to the creation of the .iso file. The following command will create the iso file named test.iso.

dd if=/dev/cdrom of=test.iso bs=1024

Now wait for the command to finish. This may take some time depending on the size of the data on the disc.

Create .iso from a folder

Step 1:
In order to create an iso from a folder we need to install the program mkisofs. Just type:

sudo apt-get install mkisofs

Step 2:
Now we create the iso file (test.iso) from a folder in our system.

mkisofs -r -o test.iso /path_to_folder/

Step 3:
It is suggested to create an MD5 checksum from the iso file so we can validate the integrity of the file in the future. This is done with the following command:

md5sum test.iso > test.iso.md5

Clear history

2008-10-24T00:55:00.001-07:00

0. Description
How to clear the history of command you have typed on bash.
I.e. how to clear the list of commands that you get with

$ history

1. How
Just clear the file ~/.bash_history

$ echo > ~/.bash_history

2. Verification
Now "$ history" should give an empty list of commands.

/etc/apt/sources.list (for hardy)

2008-10-23T23:32:00.000-07:00

Note: This post will be constantly updated.

0. Description
My list of repositories (/etc/apt/sources.list) for Ubuntu Hardy.
- includes Medibuntu repository (acroread, skype, opera, etc)

1. /etc/apt/sources.list
#deb cdrom:[Ubuntu 8.04 _Hardy Heron_ - Release i386 (20080423)]/ hardy main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://gr.archive.ubuntu.com/ubuntu/ hardy main restricted
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://gr.archive.ubuntu.com/ubuntu/ hardy-updates main restricted
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://gr.archive.ubuntu.com/ubuntu/ hardy universe
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy universe
deb http://gr.archive.ubuntu.com/ubuntu/ hardy-updates universe
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://gr.archive.ubuntu.com/ubuntu/ hardy multiverse
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy multiverse
deb http://gr.archive.ubuntu.com/ubuntu/ hardy-updates multiverse
#deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://gr.archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse
# deb-src http://gr.archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository. This software is not part of Ubuntu, but is
## offered by Canonical and the respective vendors as a service to Ubuntu
## users.
deb http://archive.canonical.com/ubuntu hardy partner
# deb-src http://archive.canonical.com/ubuntu hardy partner

deb http://security.ubuntu.com/ubuntu hardy-security main restricted
#deb-src http://security.ubuntu.com/ubuntu hardy-security main restricted
deb http://security.ubuntu.com/ubuntu hardy-security universe
#deb-src http://security.ubuntu.com/ubuntu hardy-security universe
deb http://security.ubuntu.com/ubuntu hardy-security multiverse
#deb-src http://security.ubuntu.com/ubuntu hardy-security multiverse

## Medibuntu
## add gpg key: #wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | apt-key add -
deb http://packages.medibuntu.org/ hardy free non-free

References
Medibuntu......http://ubuntuforums.org/showthread.php?t=713009