First, in order to start editing the pdf files, you have to install two packages, namely Ghostscript and PDFTK. Now, in order to merge the two files enter the following in the terminal:

gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=firstANDsecond.pdf -dBATCH first.pdf second.pdf

Notice the “AND” between the first and second files.

Now, in order to reduce the size of the pdf files, you will have to type the following in the terminal:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

I hope this post is helpful.

Under Linux, all you have to do is to open up a terminal and type:

convert oldfile.jpg newfile.pdf

Is this not beautiful ?

The other day, I needed to scan a paper, and whilst I was at my friends house, we could not use his laptop (which still had Windows XP installed) to connect to the scanner since the scanner driver CD was lost. We hooked the scanner to my laptop, et voilà !! I could scan my document and everything went superbly.

However, life is not all beer and skittles (not for all of us anyway) !! There are some problems when dealing with the new OS. For one thing, there are some problems with the new version of Firefox: When using Firefox with any Extensions, I could not use my keyboard to move around. copy and paste or use the tab key. I believe there is a fault in some upgrade file.

All in all, it is quite interesting to see that Ubuntu is becoming a more mature and more user friendly. My mother, recently quite IT-illiterate currently uses Ubuntu to, inter alia, surf the net and listen to music !! This, in my view means that with time, Ubuntu, and other types of Linux distributions will become more user friendly, easier to use and maintain their main allure as well, namely: no license fee, and most importantly, no vendor-lock.

1. First you need to download the source code package.
2. Uncompress the source code package.
3. Enter the folder
4. Now you need to install the required packages sudo apt-get install build-essential libx11-dev libxft2-dev xorg-dev
5. Here you start with configuration, there are many compilation options. You can check them by entering ./configure --help
6. I used the following command, the python parameter is to instruct the compiler to compile the python interface ./configure --enable-opengl --prefix=/usr/local --enable-python --enable-debug

7. Now the making sudo make
8. The installing sudo make install
9. Now go to gedit /etc/ld.so.conf.d/libc.conf
10. Add the following line, do not forget to replace $ROOT by the path to the root folder on your computer $ROOT/lib
11. sudo ldconfig

This worked for me.

ENJOY!

The upgrade was easy with the help of the official upgrade tutorial,  FileZilla and PHPMyAdmin. It was just a matter of downloading, uploading and overwriting. Till now everything works fine. The new wordpress panel interface is really awesome . You feel you want to write more and more .

All the plugins were upgraded successfully except the Automatic Upgrade plugin. Anyway, I don’t think I want it anymore, especially that worpdress provide that nowadays by default. Check your /wp-admin/update-core.php to see if you have it or not.

I think I should maintain a backup for the wordpress in my repository, not sure if databases are maintained under common version control systems.

For anyone who did not upgrade yet, don’t let terrorism to take over the internet. Fight fear and confusion by upgrading your wordpress. Don’t forget that you are always standing on the shoulders of giants, Wordpress !.

The solution as mention in ubuntu forums [1]

1. Download the file here:

   http://download.wolfram.com/?key=61JJHE

2. Place the shared library in
   /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Libraries/Linux
3. Download these files:

   http://download.wolfram.com/?key=MK4ZR8
   http://download.wolfram.com/?key=YHDAH4

4. Place them in
   /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Libraries/Linux-x86-64

Good Luck

Java used mainly in Mathematica in the documentation center, and this usage allocated about 15% of the CPU to Java all the time, to reduce the usage you have to replace JLink folder with patched one.

1. wget http://download.wolfram.com/download/GM5YM4/JLink.zip
2. extract the zip file
3. Replace the /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Links/Jlink with the new folder

If you don’t want Java anymore your can use this trick, notice that you will block the documentation center. However, you can use http://reference.wolfram.com instead.

1. Renaming the folder
   mv /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Links/JLink /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Links/JLink_old
2. OR Making it not executable
   chmod a-x chmod a-x /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Links/JLink

Sources:

1. The patched folder
2. Renaming option [1][2]

Now, to solve the problem for Mathematica you have two options:

1. Run Mathematica with mesa option
   mathematica -mesa

2. • Modify /etc/X11/xorg.conf to add the UXA option
     Section "Device"
Identifier "Configured Video Device"
Option "AccelMethod" "uxa"
EndSection

   • Logout to restart the X server

   Notice: Don’t forget to backup your xorg.conf before editing

Sources:

1. UXA option
2. Mesa option

To solve the problem, you can:

1. Fix the konica driver
2. Install a virtual machine XP using virtualbox and connect it to the network printer using the windows driver. The printing process is slow according to the usage of the NAT service. To solve such low performance use Host adapter solution from virtualbox as a networking alternative to NAT service which asks you to make many changes including creating a new virtual bridge on your ubuntu host machine , for more details read this tutorial. Eventually your new virtual XP machine will appear as a new machine in the LAN so you can order printing requests as any other XP machine. Anyway, it is not east task especially that my network has strict administration rules which does not allow giving an unauthenticated machines an IP address
3. Use generic drivers. You can pick any one of many generic drivers available by default in ubuntu :
   1. go to System/Administration/printing or run the following command
      system-config-printer
   2. Choose new printer, you will get this dialog after searching for available printers
   

   new-printer dialog

   3. After choosing the IP address of your network printer, press forward to get the “choose driver” dialog.
   4. Choose Select Printer from database then for makes choose Generic. Press forward to get the following dialog
      

      Choose Driver dialog

   5. Most of the models are working, for me PCL 5, PCL 5e and PCL 6/PCL XL work for normal printing orders, for both sides printing option only PCL6/PCL XL works, after choosing the model choose the driver the best to choose is the recommended one.
   6. After that you have to fill the name and description fields, and Yupeee you have a new printer.
   7. Try printing a test page by choosing prosperities from right click menu.

   

   Go to Settings/Tests and Maintenance. Press print test page.

Both Sides printing Option

As I said before this option is not working smoothly with all the generic drivers even it is available in most of them. For example, my network printer supports both sides option, the PCL 5 driver also give the option from the printer properties dialog but it is disabled in the evince printing dialog. Moreover, adding the both sides option to the lpr command did not work with the PCL 5 generic driver, choosing PCL6/PCL XL solved the probelm.

To check if your driver provides both sides option:

1. Go to Your Printer Properties Dialog
2. Choose Printer Options
3. Go to Gutenprint Printer Features Common
4. Change the default setting to whatever you want

Providing the option of both sides does not mean that it is guaranteed to work, so to test the option, open any pdf you have using evince, and try the printing dialog. Go to the page setup tab if the both sides option is enabled this means that it is working, if it is disabled try another generic driver.

You can pass the both sides option to the lpr command in this way:
$ lpr -P NameofYourPrinter -o InputSlot=Standard -o Resolution=FromPrintoutMode -o PageSize=A4 -o sides=two-sided-long-edge -o page-ranges=3-4 nameofthefile

I searched for a long time for a solution to make Wikipedia printed articles more elegant and practical. For example, if you want to print the printable version of the USA article this will cost you 47 page ! Changing the printing font size in Firefox browser helps. However, the printed article structure is far from being elegant: you have many white space areas and a photo or table may occupy consecutive pages in ugly and scattered way.

Apparently, there is no available firefox addons that can change the style of wikipedia article to suitable format. I think CSS and the new web fonts can be in great help [I am not sure]. PediaPress made good efforts with Wikimedia to make a new extension that allow you to collect the articles you want to be printed in one pdf file. You can also order a printed copy from pediapress. This extension which is called [collection] or [wiki-to-print] is enabled in English Wikibooks, French, Polish, Dutch, Portuguese, Spanish, and Simple English wikipedias. According to scalability issues this extension is not available directly in English Wikipedia. You can use the extension in English Wikipedia in one of these ways:

1. Collection extension is available to logged in users of English Wikiepedia. Using this solution:
   USA artcile printed in 44 pages with images in one column , the file size is 8 MB.
2. Use the pedia button in the collection extension. Using this solution:
   USA article printed in 26 pages without images in one column. The file size is 581KB
   

Moreover, I found superior solution to print wikipedia articles. Prince provide neat conversion method for HTML, XML files that generates pdf files. The software is cross platform and has a cli. Running the following command generates a pdf file for the USA article in 28 pages with images in 2 columns. The file size is 1.3MB.

rami@rami-desktop:~$ prince --no-author-style
-s http://www.princexml.com/howcome2008/wikipedia/wiki2.css
http://en.wikipedia.org/wiki/Usa -o usa.pdf

I used the prince software to print the wikipedia article on Neural Networks. Once Shariq saw the output, he said it is like a conference paper. Mustafa replied that it is even in a better quality.