Posts Tagged ‘Desktop’

Cannot Delete file on Desktop on Windows XP – The process cannot access the file because it is being used by another process.

Wednesday, August 13th, 2014

delete-locked-file-in-windows-xp-7-cannot-delete-file-on-desktop-windows-xp-file-used-by-another-process-solution-fix
I had to fix recently another Windows XP infected with plenty of malicious malware. I've used tips from http://malwaretips.com/blogs/ and launch all suggested tools to cleanup the PC. Some few thousands of infections were cleaned and the PC started working much better than earlier, however still there was one weird issue on the Windows XP desktop there was an .exe file hanging with 0 bytes size and whenever I tried to delete the file either from GUI or command line with (del command) it refused to delete with error:
 

The process cannot access the file because it is being used by another process.


Well the message clearly shows, the file can't be deleted because some program was using it however I couldn't see any program that has locked the .exe file. I've checked that in (Windows Task Manager) run from

Start -> Run:

taskmgr


I've done a quick search online to see, whether someone has fixed the issues, and saw many threads talking about the issue suggesting that the issue got solved Windows XP OS re-install, as this was not an option for me because the PC's reinstall would be at least a 2 day time work, plus it contains some programs which will probably be hard to freshly install, because they're no longed supported.

Finally I've seen in this thread suggestion to try to kill Windows Explorer after you have opened windows with windows cmd.exe because this will prevent the .exe file being locked by Windows Explorer and will allow it to be deleted with del command. This actually worked. I've launched

Start -> Run

taskmgr

windows-kill-explorer-process-to-delete-explorer-locked-file-on-windows-xp-desktop

and

cmd.exe

Found explorer.exe process and killed it, this makes the whole desktop (icons, start menu etc. disappear) – as Windows Explorer is main managing Windows app. Then using Alt+Tab to switch to Command Prompt window deleted it with:
 

del  Process_that_cannot_be_killed.exe


And finally succesfully deleted it 🙂


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Linux convert and read .mht (Microsoft html) file format. MHT format explained

Thursday, June 5th, 2014

linux-open-and-convert-mht-file-format-to-html-howto
If you're using Linux as a Desktop system sooner or later you will receive an email with instructions or an html page stored in .mht file format.
So what is mht? MHT is an webpage archive format (short for MIME HTML document). MHTML saves the Web page content and incorporates external resources, such as images, applets, Flash animations and so on, into HTML documents. Usually those .mht files were produced with Microsoft Internet Explorer – saving pages through:

File -> Save As (Save WebPage) dialog saves pages in .MHT.

To open those .mht files on Linux, where Firefox is available add the UNMHT FF Extension to browser. Besides allowing you to view MHT on Linux, whether some customer is requiring a copy of an HTML page in MHT, UNMHT allows you to also save complete web pages, including text and graphics, into a MHT file.
There is also support for Google Chrome browser for MHT opening and saving via a plugin called IETAB. But unfortunately IETAB is not supported in Linux.
Anyways IETAB is worthy to mention here as if your'e a Windows users and you want to browse pages compatible only with Internet Explorer, IETAB will emulates exactly IE by using IE rendering engine in Chrome  and supports Active X Controls. IETAB is a great extension for QA (web testers) using Windows for desktop who prefer to not use IE for security reasons. IETab supports IE6, IE7, IE8 and IE9.

Another way to convert .MHT content file into HTML is to use Linux KDE's mhttohtml tool.

linux-kde-converter-mhttohtml

Another approach to open .MHT files in Linux is to use Opera browser for Linux which has support for .MHT

Note that because MHT files could be storing potentially malicious content (like embedded Malware) it is always wise when opening MHT on Windows to assure you have scanned the file with Antivirus program. Often mails containing .MHT from unknown recipients are containing viruses or malware. Also links embedded into MHT file could easily expose you to spoof attacks. MHT files are encoded in combination of plain text MIMEs and BASE64 encoding scheme, MHT's mimetype is:

MIME type: message/rfc822
 


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MySQL SSL Configure Howto – How to Make MySQL communication secured

Wednesday, January 15th, 2014

mysql-over-ssl-how-to-configure-logo how to configure ssl on mysql server

Recently I've been asked How to make communication to MySQL database encrypted. The question was raised by a fellow developer who works on developing a Desktop standalone application in Delphi Programming Language with DevArt an (SQL Connection Component capable to connect Delphi applications to multiple databases like MySQL, Oracle, PostgreSQL, Interbase, Firebird etc.

Communicating in Secured form to MySQL database is not common task to do, as MySQL usually communicates to applications hosted on same server or applications to communicate to MySQL are in secured DMZ or administrated via phpMyAdmin web interface.

MySQL supports encrypted connections to itself using Secure Socket Layer (SSL) encryption. Setting up MySQL db to be communicated encrypted is a must for standalone Desktop applications which has to extract / insert data via remote SQL.
Configuring SQL to support communicated queries encrpytion is supported by default and easily configured on most standard Linux version distributions (Debian, RHEL, Fedora) with no need to recompile it.
1. Generate SSL Certificates

$ mkdir /etc/mysql-ssl && cd mysql-ssl

# Create CA certificate
$ openssl genrsa 2048 > ca-key.pem
$ openssl req -new -x509 -nodes -days 3600 \
         -key ca-key.pem -out ca-cert.pem

Create server certificate, remove passphrase, and sign it
server-cert.pem is public key, server-key.pem is private key
$ openssl req -newkey rsa:2048 -days 3600 \
         -nodes -keyout server-key.pem -out server-req.pem

$ openssl rsa -in server-key.pem -out server-key.pem
$ openssl x509 -req -in server-req.pem -days 3600 \
         -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 -out server-cert.pem

Create client certificate, remove passphrase, and sign it
client-cert.pem is public key and client-key.pem is private key
$ openssl req -newkey rsa:2048 -days 3600 \
         -nodes -keyout client-key.pem -out client-req.pem

$ openssl rsa -in client-key.pem -out client-key.pem
$ openssl x509 -req -in client-req.pem -days 3600 \
         -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 -out client-cert.pem

After generating the certificates, verify them:

$ openssl verify -CAfile ca-cert.pem server-cert.pem client-cert.pem
 

2. Add SSL support variables to my.cnf

Once SSL key pair files are generated in order to active SSL encryption support in MySQL server, add to (/etc/my.cnf,  /etc/mysql/my.cnf, /usr/local/etc/my.cnf … ) or wherever config is depending on distro

# SSL
ssl-ca=/etc/mysql-ssl/ca-cert.pem
ssl-cert=/etc/mysql-ssl/server-cert.pem
ssl-key=/etc/mysql-ssl/server-key.pem

3. Restart MySQL server

/etc/init.d/mysqld restart
...

4. Create SQL user to require SSL login

Create new user with access to database;

GRANT ALL ON Sql_User_DB.* TO Sql_User@localhost;
FLUSH PRIVILEGES;

To create administrator privileges user:

GRANT ALL PRIVILEGES ON *.* TO ‘ssluser’@'%’ IDENTIFIED BY ‘pass’ REQUIRE SSL;
FLUSH PRIVILEGES;

5. Test SSL Connection with MySQL CLI client or with few lines of PHP

To use mysql cli for testing whether SSL connection works:

$ mysql -u ssluser -p'pass' –ssl-ca /etc/mysql-ssl/client-cert.pem –ssl-cert /etc/mysql-ssl/client-key.pem

Once connected to MySQL to verify SSL connection works fine:

mysql> SHOW STATUS LIKE 'Ssl_Cipher';
 +---------------+--------------------+
| Variable_name | Value              |
 +---------------+--------------------+
| Ssl_cipher    | DHE-RSA-AES256-SHA |
+---------------+--------------------+

If you get this output this means MySQL SSL Connection is working as should.

Alternative way is to use test-mysqli-ssl.php script to test availability to mysql over SSL.

$conn=mysqli_init();
mysqli_ssl_set($conn, '/etc/mysql-ssl/client-key.pem', '/etc/mysql-ssl/client-cert.pem', NULL, NULL, NULL);
if (!mysqli_real_connect($conn, '127.0.0.1', 'ssluser', 'pass')) { die(); }
$res = mysqli_query($conn, 'SHOW STATUS like "Ssl_cipher"');
print_r(mysqli_fetch_row($res));
mysqli_close($conn);

Note: Change username password according to your user / pass before using the script

That's all now you have mysql communicating queries data over SSL

 


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Torus Trooper – Cool 3D Tunnel Speed Up Spaceship game for Linux

Wednesday, December 18th, 2013

Torus Trooper linux tunnel 3d fast pace speed up game screenshot

Whether you're looking for a game to kill some time and enjoy the old "spaceship shoot and run games" check out Torus Trooper.
Originally game was developed for MS Windows and is remake of an old Atari Arcade Game Tempest.

Those who played Tempest know well that this game was revolution for its time and probably remember also a similar world famous Space Duel game.

Arcade atari old scool tunnel game tempest one of atari pre 3d game classics

Atari's Tempest Arcade game

The objective of Torus Trooper is mega simple as in most arcade games. You're speeding up through a tunnel all time with a spaceship with the only goal to kill as many enemies  as you can and survive as longer as possible. Playing the game you can get some memories of demoscene tracked music, future crew Second Reality / Unreal demos. Game was created by ABA GAMES company, authors Tumiki Fighters and GunRoar another 2 nice 2D Linux arcade games.

TUMIKI Fighters the boss level 1, 2d linux arcade game classic

Tumiki Fighters

Gunroar another cool linux arcade 2d game

GunRoar

Probably best thing of Torus Trooper is its nice graphics and superb demoscene like soundtrack.
I truely love the pace of the game, raising up the player adrenaline in minutes.
To install in a bundle Torus-Trooper Tumiki Fighters and Gunroar on Debian / Ubuntu Linux run the usual:

debian:~# apt-get install --yes torus-trooper tumiki-fighters gunroar
...

There is also a variation of torus-trooper called Torus Trooper, install and give it a try as well;

debian:~# apt-get install -yes torus-trooper-pure
...

In my humble opinion Torus-trooper is among golden games every Linux gamer should have installed on his Desktop.
Enjoy 🙂
 


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How to disable Debian GNU / Linux (Squeeze) Apache 2 version reporting to improve security – Hide Apache server version

Friday, October 5th, 2012

Debian GNU / Linux's Apache default behavior is to report Apache server name, version and Linux distribution version and codename.
This is shown as a minor security leak in many Security Scanner (audit) software like Nessus. It reveals a vital information which could help malicious attacker later to use exploit if the version number in question is vulnerable.

The quickest way to check, either Apache versioning and distro info is disabled is with telnet:

hipo@noah:~/Desktop$ telnet pc-freak.net 80
Trying 83.228.93.76…
Connected to pc-freak.net.
Escape character is '^]'.
HEAD / HTTP/1.0

Connection closed by foreign host.
hipo@noah:~/Desktop$ telnet pc-freak.net 80
Trying 83.228.93.76…
Connected to pc-freak.net.
Escape character is '^]'.
HEAD / HTTP/1.0

HTTP/1.1 200 OK
Date: Fri, 05 Oct 2012 10:48:36 GMT
Server: Apache/2.2.16 (Debian)
X-Powered-By: PHP/5.3.3-7+squeeze14
Vary: Accept-Encoding
Connection: close
Content-Type: text/html

Disabling this Distro version codename and version number reporting on Debian is done by changing in file /etc/apache2/conf.d/security directives:


ServerTokens OS
ServerSignature On

to


ServerSignature Off
ServerTokens ProductOnly

Here important note to make is if you try adding:

ServerSignature Off and ServerTokens Prod straight in Debian general config /etc/apache2/apache2.conf, but did not change the settings set for the vars through /etc/apache2/conf.d/security; settings from /etc/apache2/conf.d/security will overwrite ServerSignature / ServerTokens settings set in /etc/apache2/apache2.conf

I tried this myself (forgotting about /etc/apache2/conf.d/security) and adding both variables straight in apache2.conf. After Apache restart Apache version number and type of distribution continued be returned by the WebServer.
I thought something specific changed in Debian Squeeze – Apache/2.2.16 so this two variables are probably not working so I did a quick research online seing other people complaining also unable to disable Apache ver and Linux distro version and looking for a reason why. Well anyways if you happen to also ponder, why ServerSignature Off and ServerTokens ProductOnly does not take effect keep in mind it is due to overwritten settings via /etc/apache2/conf.d/security, changing the values there and restarting Apache and you're done 🙂

To make sure 100% Apache is no longer returning exact version number and host installed distro type, use telnet again:

hipo@noah:~/Desktop$ telnet pc-freak.net 80
Trying 83.228.93.76…
Connected to pc-freak.net.
Escape character is '^]'.
HEAD / HTTP/1.0

Connection closed by foreign host.


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30 years anniversary of the first mass produced portable computer COMPAQ Grid Compass 1011

Thursday, July 19th, 2012

Grid Notebook Big screen logo

Today it is considered the modern laptop (portable computers) are turning 30 years old. The notebook grandparent is a COMPAQGRiD Compass 1011 – a “mobile computer” with a electroluminescent display (ELD) screen supporting resolution of 320×240 pixels. The screen allowed the user to use the computer console in a text resolution of 80×24 chars. This portable high-tech gadget was equipped with magnesium alloy case, an Inten 8086 CPU (XT processor) at 8Mhz (like my old desktop pravetz pc 😉 ), 340 kilobyte (internal non-removable magnetic bubble memory and even a 1,200 bit/s modem!

COMPAQ Grid Compass considered first laptop / notebook on earthy 30 anniversary of the portable computer

The machine was uniquely compatible for its time as one could easily attach devices such as floppy 5.25 inch drives and external (10 Meg) hard disk via IEEE-488 I/O compatible protocol called GPiB (General Purpose instrumental Bus).

First mass prdocued portable computer laptop grid COMPAQ 11011 back side input peripherals

The laptop had also unique small weight of only 5 kg and a rechargable batteries with a power unit (like modern laptops) connectable to a normal (110/220 V) room plug.

First notebook in World ever the COMPAQ grid Compass 1101,br />
The machine was bundled with an own specificly written OS GRiD-OS. GRID-OS could only run a specialized software so this made the application available a bit limited.
Shortly after market introduction because of the incompitablity of GRID-OS, grid was shipped with MS-DOS v. 2.0.
This primitive laptop computer was developed for serve mainly the needs of business users and military purposes (NASA, U.S. military) etc.

GRID was even used on Space Shuttles during 1980 – 1990s.
The price of the machine in April 1982 when GriD Compass was introduced was the shockingly high – $8150 dollars.

The machine hardware design is quite elegant as you can see on below pic:

 COMPAQ grid laptop 1101 bubbles internal memory

As a computer history geek, I’ve researched further on GRID Compass and found a nice 1:30 hour video telling in detailed presentation retelling the history.

Shortly after COMPAQ’s Grid Compass 1011’s introduction, many other companies started producing similar sized computers; one example for this was the Epson HX-20 notebook. 30 years later, probably around 70% of citizens on the globe owns a laptop or some kind of portable computer device (smartphone, tablet, ultra-book etc.).

Most of computer users owning a desktop nowdays, owns a laptop too for mobility reasons. Interestengly even 30 years later the laptop as we know it is still in a shape (form) very similar to its original predecessor. Today the notebook sales are starting to be overshadowed by tablets and ultra-books (for second quarter laptop sales raised 5% but if compared with 2011, the sales rise is lesser 1.8% – according to data provided by Digital Research agency). There are estimations done by (Forrester Research) pointing until the end of year 2015, sales of notebook substitute portable devices will exceed the overall sales of notebooks. It is manifested today the market dynamics are changing in favour of tabets and the so called next generation laptopsULTRA-BOOKS. It is a mass hype and a marketing lie that Ultra-Books are somehow different from laptops. The difference between a classical laptop and Ultra-Books is the thinner size, less weight and often longer battery use time. Actually Ultra-Books are copying the design concept of Mac MacBook Air trying to resell under a lound name.
Even if in future Ipads, Android tablets, Ultra-Books or whatever kind of mambo-jambo portable devices flood the market, laptops will still be heavily used in future by programmers, office workers, company employees and any person who is in need to do a lot of regular text editting, email use and work with corporative apps. Hence we will see a COMPAC Grid Compass 1011 notebook likes to be dominant until end of the decade.

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Installing XMMS on Debian Squeeze from a Package / Installing XMMS on Debian – the debian way

Tuesday, July 17th, 2012

installing xmms on debian squeeze linux playing free software song green skin screenshot

I use Debian Linux for my desktop for quite some time; Even though there are plenty of MP3 / CD players around in Debian, I’m used to the good old XMMS, hence I often prefer to use XMMS to play my music instead of newer players like RhythmBox or audacious.
Actually audacious is not bad substitute for XMMS and is by default part of Debian but to me it seems more buggy and tends to crash during playing some music formats more than xmms ….

As most people might know, XMMS is no longer supported in almost all modern Linux distributions, so anyone using Debian, Ubuntu or other deb derivative Linux would have to normally compile it from source.
Compiling from source is time consuming and I think often it doesn’t pay back the effort. Thanksfully, though not officially supported by Debian crew XMMS still can be installed using a deb xmms prebuilt package repository kindly provided by a hacker fellow knuta.

Using the pre-build deb packages, installing xmms on new Debian installs comes to:

debian:~# echo 'deb http://www.pvv.ntnu.no/~knuta/xmms/squeeze ./' >> /etc/apt/sources.list
debian:~# echo 'deb-src http://www.pvv.ntnu.no/~knuta/xmms/squeeze ./' >> /etc/apt/sources.list
debian:~# apt-get update && apt-get -y install xmms

There are also deb xmms built for Ubuntu, so Ubuntu users could install xmms using repositories:

deb http://www.pvv.ntnu.no/~knuta/xmms/karmic ./
deb-src http://www.pvv.ntnu.no/~knuta/xmms/karmic ./
That’s all now xmms is ready to use. Enjoy 🙂

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Fixing QMAIL mail server SMTP auto-configure issues in Thunderbird and other mail IMAP / POP3 mobile clients

Friday, July 13th, 2012

One of the QMAIL mail servers, setup-uped on a Debian host has been creating some auto configuration issues. Every-time a new mail user tries to use the embedded Thunderbird client auto configuration, the auto config fails leaving the client unable to use his Mailbox through POP3 or IMAP protocols.

Since about 2 years Thunderbird and many other modern pop3 and imap mail desktop and mobile clients are by default using the auto configuration and hence it was unthinkable to manually change settings for new clients with the QMAIl install; Besides that most of the Office users are always confused, whether they have to manually change SMTP or POP3 host for a server.

Below is a screenshot displaying the warning during email auto-configuration:

Thunderbird new Mail account setup auto config warning SMTP not OKThe orange color in the button for the newly auto-detected smtp.mail-domain.com indicates, something is not right with the SMTP host.

Obviously, something was wrong with smtp.mail-domain.com, hence I checked where smtp.mail.domain.com resolves with host command. What I found was actually smtp.mail-domain.com Active ( A ) DNS records was pointing to an IP address, our company previously used for the mail server. At present time the correct mail server host name is mx.mail-domain.com and the QMAIL installation on mx.soccerfame.com is configured to be the actual SMTP server.

By default Thunderbird and many other POP3, IMAP mail clients, however automatically assume the default SMTP host for a mail server is to be configured under a host name smtp.mail-domain.com. This is really strange, especially when the primary MX record for mail-domain.com domain is pointing to mx.mail-domain.com, e.g.:

qmail:~# host -t MX mail-domain.com
soccerfame.com mail is handled by 10 mx.mail-domain.com.
soccerfame.com mail is handled by 20 mail.mail-domain.com.
soccerfame.com mail is handled by 30 mail-domain.com.

The whole warning was caused due to the fact mx.mail-domain.com was resolving to an IP like xxx.xxx.xxx.xxx, whether smtp.mail-domain.com was resolving to yyy.yyy.yyy.yyy

Both xxx.xxx.xxx.xxx and yyy.yyy.yyy.yyy hosts were configured to have a different qmail SMTP host i.e.:

The server under IP xxx.xxx.xxx.xxx – (mx.mail-domain.com) was configured in /var/qmail/control/me to be mx.mail-domain.com and the other old one yyy.yyy.yyy.yyy – (mail.mail-domain.com) had (mail.mail-domain.com) in /var/qmail/control/me

As smtp.mail-domain.com was actually being still resolved to mail.mail-domain.com, the EMAILs were improperly trying to be sent with a configured DNS hostname of smtp.mail-domain.com, where the actual one on the server was mail.mail-domain

It took, me about an hour of pondering what is causing the oddities until I got the here explained issue. As the DNS recors for the domain the sample mail-domain.com were handled by Godaddy, to fix the mess, I logged in to Godaddy and;

a) deleted – DNS record for smtp.mail-domain.com.
b) Created new CNAME record for smtp.mail-domain.com to be a domain alias for mx.soccerfame.com

A few minutes, afterwards I tried configuring once again the same email account in Thunderbird and this time both imap.mail-domain.com and smtp.mail-domain.com turned green; indicating everything is configured fine.

To be 100% sure all is working fine I first fetched, all email via the IMAP protocol without hassles and onwards sent a test email to my Gmail account; thanksfully the sent email was delivered to Gmail indicating both Get Mail and Send Mail functions worked now fine.

Thunderbird icedove new mail account setup auto config Okay
 


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After a loooongg, looong waiting finally a New Version of Skype 4.0 is out – Skype 4 on Debian GNU / Linux short review

Sunday, June 17th, 2012

After about 3 years of no new version for GNU / Linux finally Skype has released a new version of Skype.
I thought already there will be never a new skype version out for GNU / Linux, since the moment Microsoft purchased skype.

Now suddenly and quite in quiet the new version of Skype 4.0 is out for download from Skype's website. The latest Skype download for Linux is to be found here

As of time of writting this post there are Skype 4 versions for following Linux-es;;;
 

  • Ubuntu 10.04 32 / 64-bit (probably would work fine on latest Ubuntus too)
  • Debian 6.0 Squeeze 32 / 64-bit
  • Fedora 16 / 32 bit
  • OpenSUSE 12.1 32bit (only)
  • Most likely the Ubuntu release of skype 4 will work flawlessly on Linux Mint and other debian derivatives.The The release mentions, Skype 4 is supposed to have 4 major advancements and the gap in interface and usability with latest Mac OS and M$ Windows Skype versions is now filled.The four major changes said in the announcement are;;;

  • 1. a new Conversations View where users can easily track all of their chats in a unified window.
    Those users who prefer the old view can disable this in the Chat options;
  • 2. a brand new Call View;
  • 3.Call quality has never been better thanks to several investments we made in improving audio quality;
  • 4. Improved video call quality and extended support for more cameras.
  • Some of the minor improvements in those

  • new Linux skype
  • are:- improved chat synchronization- new presence and emoticon icons- the ability to store and view phone numbers in a Skype contact's profile- much lower chance Skype for Linux will crash or freeze- chat history loading is now much faster- support for two new languages: Czech (flag:cz) and Norwegian (flag:no)Just like with prior Skype releases 2.0 and 2.2beta this release comes with almost same list of non-english language support ,,,Seeing those announcement, I've hurried to download and test skype 4 on my 64-bit desktop running Debian 6 Squeeze.Once downloaded to install the pack skype-debian_4.0.0.7-1_amd64.deb I used the usual dpkg -i i,e,;;;noah:~# dpkg -iskype-debian_4.0.0.7-1_amd64.deb…………..Just like the release announcement mentions the first initial launch of Skype 4 took about 3 or 4 minutes doing something (probably sending half of my hard disk data to Microsoft 🙂 🙂 🙂 ) along with importing the prior skype data and chat history :)The minimum software dependencies for correct operation of Skype are:Qt libraries; D-Bus; libasound and pulseaudioHere are few screenshots of Skype 4 to give you an idea what to expect:The Skype Options is almost identical to Skype 2.2. One interesting new feature I've noticed is Skype WIFIUnfortunately to use Skype WIFI you need to have purchased skype credits.Another notable difference is the organization of Skype Chats, which is more like in the good old times of mIRC and IRC chat clientsHere is also the list of Skype emoticons including bundled with Skype 4:The "look & feel" of the new interface gives the impression of seriously improved Skype client stability too.There was a minor trouble with the voice recording (microphone) with Skype 4;To make the microphone work properly I had to raise up the mic volume from PulseAudio settings in Skype options.Well that's all the only unpleasent thing for this new skype is it is using KDE's libQT and seems not to have a native interface for GNOME via GTK2. If we put away this I guess this version of Skype is much more stable and therefore I would recommend anyone to update.Of course we never know if this new updated more stable Skype release is not filled up with backdoors or does not transfer all our conversations to microsoft but we didn't know that even when Skype was not Microsoft's so and since it is not a free software I guess it doesn't matter so much.As you can guess Microsoft has imposed centralization on Skype protocol so connecting the peers is now done by Microsoft servers this news is another intriguing one.According to one recent article from May 1, 2012 Microsoft Skype replaces the Peer-to-Peer P2P supernodes with Linux boxes hosted by Microsoft – In short that probably means that by changing this nowdays microsoft probably now logs all chat sessions between Skype users, even it is likely the calls between users are recorded too. We all know Microsoft imperialism pretty well so I guess this is not a big news …..This new release of Skype if it is significantly more stable than it is prior releases would certainly have serious positive implication on the development and adoption of Linux for the Desktop. So far I'm sure one of the obstacles of many manufacturers of notebooks and comp equipment to ship with Linux was the lack of a stable and easy to implement skype release for Linux.Well that's all folks. Enjoy the New Skype Cheeres ! 🙂


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How to add support for DJVU file format on M$ Windows, Mac, GNU / Linux and FreeBSD

Thursday, June 14th, 2012

Windjview Format paper Clipper logo / support DjView on Windows and Linux

By default there is no way to see what is inside a DJVU formatted document on both Windows and Linux OS platforms. It was just a few months ago I saw on one computer I had to fix up the DJVU format. DJVU format was developed for storing primary scanned documents which is rich in text and drawings.
Many old and ancient documents for example Church books in latin and some older stuff is only to be found online in DJVU format.
The main advantage of DJVU over lets say PDF which is also good for storing text and visual data is that DJVU's data encoding makes the files much more smaller in size, while still the quality of the scanned document is well readable for human eye.

DJVU is a file format alternative to PDF which we all know has been set itself to be one of the major standard formats for distributing electronic documents.

Besides old books there are plenty of old magazines, rare reports, tech reports newspapers from 1st and 2nd World War etc in DJVU.
A typical DJVU document takes a size of only lets say 50 to 100 KBytes of size just for comparison most a typical PDF encoded document is approximately sized 500 KiloBytes.

1.% Reading DJVU's on M$ Windoze and Mac-s (WinDjView)

The program reader for DJVU files in Windows is WinDjView WinDjView official download site is here

WinDjView is licensed under GPLv2 is a free software licensed under GPL2.

WinDjView works fine on all popular Windows versions (7, Vista, 2003, XP, 2000, ME, 98, NT4).

WinDjView with opened old document Sol manual ,,,,

I've made a mirror copy of WinDjView for download here (just in case something happens with the present release and someone needs it in future).

For Mac users there is also a port of WinDjView called MacDjView ;;;,

2.% Reading DJVU files on GNU / Linux

The library capable of rendering DJVUs in both Linux and Windows is djviewlibre again free software (A small note to make here is WinDjView also uses djviewlibre to render DJVU file content).

The program that is capable of viewing DJVU files in Linux is called djview4 I have so far tested it only with Debian GNU / Linux.

To add support to a desktop Debian GNU / Linux rel. (6.0.2) Squeeze, had to install following debs ;;;

debian:~# apt-get install --yes djview4 djvulibre-bin djviewlibre-desktop libdjviewlibre-text pdf2djvu
........
...

pdf2djvu is not really necessery to install but I installed it since I think it is a good idea to have a PDF to DJVU converter on the system in case I somedays need it ;;;

djview4 is based on KDE's QT library, so unfortunately users like me who use GNOME for a desktop environment will have the QT library installed as a requirement of above apt-get ;;;

Here is Djview4 screenshot with one opened old times Bulgarian magazine called Computer – for you

DJVU Pravetz Computer for you old school Bulgarian Pravetz magazine

Though the magazine opens fine, every now and then I got some spit errors whether scrolling the pages, but it could be due to improperly encoded DJVU file and not due to the reader. Pitily, whether I tried to maximize the PDF and read it in fullscreen I got (segfault) error and the program failed. Anyways at least I can read the magazine in non-fullscreen mode ;;; ,,,,

3.% Reading DJVU's on FreeBSD and (other BSDs)

Desktop FreeBSD users and other BSD OS enthusiasts could also use djview4 to view DJVUs as there is a BSD port in the ports tree.
To use it on BSD I had to install port /usr/ports/graphics/djview4:

freebsd# cd /usr/ports/graphics/djview4
freebsd# make install clean
,,,,...

For G / Linux users who has to do stuff with DJVU files, there are two other programs which might be useful:
 

  • a) djvusmooth – graphical editor for DjVu
  • b) gscan2pdf – A GUI to produce PDFs or DjVus from scanned documents

DJVUSmooth Debian GNU / Linux opened prog

I tried djusmooth to edit the same PDF magazine which I prior opened but I got an Unhandled exception: IOError, as you can in below shot:

DJVUSmooth Unhandled Exception IOError

This is probably normal since djvusmooth is in its very early stage of development – current version is 0.2.7-1

Unfortunately I don't have a scanner at home so I can't test if gscan2pdf produces proper DJVUs from scans, anyways I installed it to at least check the program interface which on a first glimpse looks simplistic:

gscan2pdf 0.9.31 Debian Linux Squeeze screenshot
To sum it up obviously DJVU seems like a great alternative to PDF, however its support for Free Software OSes is still lacking behind.
The Current windows DJVU works way better, though hopefully this will change soon.


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