Walking in Light with Christ - Faith, Computing, Diary

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Walking in Light with Christ - Faith, Computing, Diary


Monitoring MySQL server queries and debunning performance (slow query) issues in console / terminal with native MySQL commands, mtop, mytop

Posted: 10 May 2012 09:59 AM PDT

If you’re a Linux server administrator running MySQL server, you need to troubleshoot performance and bottleneck issues with the SQL database every now and then. In this article, I will pinpoint few methods to debug basic issues with MySQL database servers.

1. Troubleshooting MySQL database queries with native SQL commands

a)One way to debug errors and get general statistics is by logging in with mysql cli and check the mysql server status:

# mysql -u root -p
mysql> SHOW STATUS;
+-----------------------------------+------------+
| Variable_name | Value |
+-----------------------------------+------------+
| Aborted_clients | 1132 |
| Aborted_connects | 58 |
| Binlog_cache_disk_use | 185 |
| Binlog_cache_use | 2542 |
| Bytes_received | 115 |
.....
.....
| Com_xa_start | 0 |
| Compression | OFF |
| Connections | 150000 |
| Created_tmp_disk_tables | 0 |
| Created_tmp_files | 221 |
| Created_tmp_tables | 1 |
| Delayed_errors | 0 |
| Delayed_insert_threads | 0 |
| Delayed_writes | 0 |
| Flush_commands | 1 |
.....
.....
| Handler_write | 132 |
| Innodb_page_size | 16384 |
| Innodb_pages_created | 6204 |
| Innodb_pages_read | 8859 |
| Innodb_pages_written | 21931 |
.....
.....
| Slave_running | OFF |
| Slow_launch_threads | 0 |
| Slow_queries | 0 |
| Sort_merge_passes | 0 |
| Sort_range | 0 |
| Sort_rows | 0 |
| Sort_scan | 0 |
| Table_locks_immediate | 4065218 |
| Table_locks_waited | 196 |
| Tc_log_max_pages_used | 0 |
| Tc_log_page_size | 0 |
| Tc_log_page_waits | 0 |
| Threads_cached | 51 |
| Threads_connected | 1 |
| Threads_created | 52 |
| Threads_running | 1 |
| Uptime | 334856 |
+-----------------------------------+------------+
225 rows in set (0.00 sec)

SHOW STATUS; command gives plenty of useful info, however it is not showing the exact list of queries currently processed by the SQL server. Therefore sometimes it is exactly a stucked (slow queries) execution, you need to debug in order to fix a lagging SQL. One way to track this slow queries is via enabling mysql slow-query.log. Anyways enabling the slow-query requires a MySQL server restart and some critical productive database servers are not so easy to restart and the SQL slow queries have to be tracked “on the fly” so to say.
Therefore, to check the exact (slow) queries processed by the SQL server (without restarting it), do

mysql> SHOW processlist;
+——+——+—————+——+———+——+————–+——————————————————————————————————+
| Id | User | Host | db | Command | Time | State | Info |
+——+——+—————+——+———+——+————–+——————————————————————————————————+
| 609 | root | localhost | blog | Sleep | 5 | | NULL |
| 1258 | root | localhost | NULL | Sleep | 85 | | NULL |
| 1308 | root | localhost | NULL | Query | 0 | NULL | show processlist |
| 1310 | blog | pcfreak:64033 | blog | Query | 0 | Sending data | SELECT comment_author, comment_author_url, comment_content, comment_post_ID, comment_ID, comment_aut |
+——+——+—————+——+———+——+————–+——————————————————————————————————+
4 rows in set (0.00 sec)
mysql>

SHOW processlist gives a good view on what is happening inside the SQL.

To get more complete information on SQL query threads use the full extra option:

mysql> SHOW full processlist;

This gives pretty full info on running threads, but unfortunately it is annoying to re-run the command again and again - constantly to press UP Arrow + Enter keys.

Hence it is useful to get the same command output, refresh periodically every few seconds. This is possible by running it through the watch command:

debian:~# watch "'show processlist' | mysql -u root -p'secret_password'"

watch will run SHOW processlist every 2 secs (this is default watch refresh time, for other timing use watch -n 1, watch -n 10 etc. etc.

The produced output will be similar to:

Every 2.0s: echo 'show processlist' | mysql -u root -p'secret_password' Thu May 10 17:24:19 2012

Id User Host db Command Time State Info
609 root localhost blog Sleep 3 NULL1258 root localhost NULL Sleep 649 NULL1542 blog pcfreak:64981 blog Query 0 Copying to tmp table \
SELECT p.ID, p.post_title, p.post_content,p.post_excerpt, p.pos
t_date, p.comment_count, count(t_r.o
1543 root localhost NULL Query 0 NULL show processlist

Though this "hack" is one of the possible ways to get some interactivity on what is happening inside SQL server databases and tables table. for administering hundred or thousand SQL servers running dozens of queries per second - monitor their behaviour few times aday using mytop or mtop is times easier.

Though, the names of the two tools are quite similar and I used to think both tools are one and the same, actually they're not but both are suitable for monitoring sql database execution in real time.

As a sys admin, I've used mytop and mtop, on almost each Linux server with MySQL server installed.
Both tools has helped me many times in debugging oddities with sql servers. Therefore my personal view is mytop and mtop should be along with the Linux sysadmin most useful command tools outfit, still I'm sure many administrators still haven't heard about this nice goodies.

1. Installing mytop on Debian, Ubuntu and other deb based GNU / Linux-es

mytop is available for easy install on Debian and across all debian / ubuntu and deb derivative distributions via apt.

Here is info obtained with apt-cache show

debian:~# apt-cache show mytop|grep -i description -A 3
Description: top like query monitor for MySQL
Mytop is a console-based tool for monitoring queries and the performance
of MySQL. It supports version 3.22.x, 3.23.x, 4.x and 5.x servers.
It's written in Perl and support connections using TCP/IP and UNIX sockets.

Installing the tool is done with the trivial:

debian:~# apt-get --yes install mytop
....

mtop used to be available for apt-get-ting in Debian Lenny and prior Debian releases but in Squeeze onwards, only mytop is included (probably due to some licensing incompitabilities with mtop??).

For those curious on how mtop / mytop works - both are perl scripts written to periodically connects to the SQL server and run commands similar to SHOW FULL PROCESSLIST;. Then, the output is parsed and displayed to the user.

Here how mytop running, looks like:

MyTOP showing queries running on Ubuntu 8.04 Linux - Debugging interactively top like MySQL

2. Installing mytop on RHEL and CentOS

By default in RHEL and CentOS and probably other RedHat based Linux-es, there is neither mtop nor mytop available in package repositories. Hence installing the tools on those is only available from 3rd parties. As of time of writting an rpm builds for RHEL and CentOS, as well as (universal rpm distros) src.rpm package is available on http://pkgs.repoforge.org/mytop/. For the sake of preservation - if in future those RPMs disappear, I made a mirror of mytop rpm's here

Mytop rpm builds depend on a package perl(Term::ReadKey), my attempt to install it on CentOS 5.6, returned following err:

[root@cenots ~]# rpm -ivh mytop-1.4-2.el5.rf.noarch.rpm
warning: mytop-1.4-2.el5.rf.noarch.rpm: Header V3 DSA signature: NOKEY, key ID 6b8d79e6
error: Failed dependencies:
perl(Term::ReadKey) is needed by mytop-1.4-2.el5.rf.noarch

The perl(Term::ReadKey package is not available in CentOS 5.6 and (probably other centos releases default repositories so I had to google perl(Term::ReadKey) I found it on http://rpm.pbone.net/ package repository, the exact url to the rpm dependency as of time of writting this post is:

ftp://ftp.pbone.net/mirror/yum.trixbox.org/centos/5/old/perl-Term-ReadKey-2.30-2.rf.i386.rpm

Quickest, way to install it is:

[root@centos ~]# rpm -ivh ftp://ftp.pbone.net/mirror/yum.trixbox.org/centos/5/old/perl-Term-ReadKey-2.30-2.rf.i386.rpmRetrieving ftp://ftp.pbone.net/mirror/yum.trixbox.org/centos/5/old/perl-Term-ReadKey-2.30-2.rf.i386.rpmPreparing... ########################################### [100%]
1:perl-Term-ReadKey ########################################### [100%]

This time mytop, install went fine:

[root@centos ~]# rpm -ivh mytop-1.4-2.el5.rf.noarch.rpm
warning: mytop-1.4-2.el5.rf.noarch.rpm: Header V3 DSA signature: NOKEY, key ID 6b8d79e6
Preparing... ########################################### [100%]
1:mytop ########################################### [100%]

To use it further, it is the usual syntax:

mytop -u username -p 'secret_password' -d database

CentOS Linux MyTOP MySQL query benchmark screenshot - vpopmail query

3. Installing mytop and mtop on FreeBSD and other BSDs

To debug the running SQL queries in a MySQL server running on FreeBSD, one could use both mytop and mtop - both are installable via ports:

a) To install mtop exec:

freebsd# cd /usr/ports/sysutils/mtop
freebsd# make install clean
....

b) To install mytop exec:

freebsd# cd /usr/ports/databases/mytop
freebsd# make install clean
....

I personally prefer to use mtop on FreeBSD, because once run it runs prompts the user to interactively type in the user/pass

freebsd# mtop

Then mtop prompts the user with "interactive" dialog screen to type in user and pass:

Mtop interactive type in username and password screenshot on FreeBSD 7.2

It is pretty annoying, same mtop like syntax don't show user/pass prompt:

freebsd# mytop
Cannot connect to MySQL server. Please check the:

* database you specified "test" (default is "test")
* username you specified "root" (default is "root")
* password you specified "" (default is "")
* hostname you specified "localhost" (default is "localhost")
* port you specified "3306" (default is 3306)
* socket you specified "" (default is "")
The options my be specified on the command-line or in a ~/.mytop
config file. See the manual (perldoc mytop) for details.
Here's the exact error from DBI. It might help you debug:
Unknown database 'test'

The correct syntax to run mytop instead is:

freebsd# mytop -u root -p 'secret_password' -d 'blog'

Or the longer more descriptive:

freebsd# mytop --user root --pass 'secret_password' --database 'blog'

By the way if you take a look at mytop's manual you will notice a tiny error in documentation, where the three options --user, --pass and --database are wrongly said to be used as -user, -pass, -database:

freebsd# mytop -user root -pass 'secret_password' -database 'blog'
Cannot connect to MySQL server. Please check the:

* database you specified "atabase" (default is "test")
* username you specified "ser" (default is "root")
* password you specified "ass" (default is "")
* hostname you specified "localhost" (default is "localhost")
* port you specified "3306" (default is 3306)
* socket you specified "" (default is "")a
...
Access denied for user 'ser'@'localhost' (using password: YES)

Actually it is interesting mytop, precededed historically mtop.
mtop was later written (probably based on mytop), to run on FreeBSD OS by a famous MySQL (IT) spec -- Jeremy Zawodny .
Anyone who has to do frequent MySQL administration tasks, should already heard Zawodny's name.
For those who haven't, Jeremy used to be a head database administrators and developer in Yahoo! Inc. some few years ago.
His website contains plenty of interesting thoughts and writtings on MySQL server and database management

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Why I never liked Mandrake Linux / Mankdrake Linux has took its name from an 1930s comics Mandrake the Magician

Posted: 09 May 2012 03:07 AM PDT

I never liked Mandrake Linux, since day 1 I saw it.
Historically Mandrake Linux was one of the best Linux distributions available for free download in the "Linux scene" some 10 to 12 years ago.

Mandrake was simple gui oriented and trendy. It also one the Linux distribution with the most simplified installer program and generally a lot of GUI software for easy configuration and use by the end user.

Though it's outside nice look, still for me it was like an "intuition" that Mandrake is not so good as it appeared.

Now many years later I found by chance that Mandrake has been sued to change their Operating System name with another, due to a law suit requit by the copyright holders of Mandrake The Magician comics. "Mandrake the Magician" used to be a very popular before the Second World war in the 1930's.

Mandrake the Magician Comics Magazine from 1930's Cover, Mandrake the Black Magic Magician

It obviously not a co-incidence that the Mandrake names was after this comics and not the mandrake herb plants available in Europe, Africa and Asia. This is clear in Mandrake Linux distro earlier mascot, you see below:

Mandrake Linux old distribution logo, magician penguin

Later on they changed Mandrake's logo to loose the connection with Mandrake The Magician and used another new crafted logo:

Mandrake GNU Linux newer logo
Its quite stunning nowdays magician obsession, has so heavily infiltrated our lives that even something like a Free Softwre Linux distribution might have some kind of reference to magician and occult stuff (I saw this from the position of being Christian) …

Later due to the name copyright infringement Mandrake Linux was renamed first to Mandragora Linux.
Instead of putting some nice name non related to occultism or magic stuff the French commercian company behind Mandrake rename it to another non-Christian name Mandragora.
Interestingly the newer name Mandragora as one can read in wikipedia means:
 

Mandragora (demon), in occultism

Well apparently, someone from the head developers of this Linux distribution has a severe obsession with magic and occultism.

Later MandrakeSoft (The French Company behind Mandrake Linux) renamed finally the distribution to Mandriva under the influence of the merger of Mandrake with the Brazillian company Connectiva this put also an over to the legal dispute copyright infringement dispute with Hearst Corporation (owning the rights of Mandrake the Magician).

Having in mind all fact on current Mandriva "dark names history", I think it is better we Christians avoid it …

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How to convert FLV to AVI and AVI to FLV Videos on Linux and BSD with avidemux and ffmpeg – Simple video editting with LiVES

Posted: 08 May 2012 01:47 AM PDT

I'm starting to learn some video editing, as I need it sometimes for building client websites.
As a Linux user I needed to have some kind of software for amateur video editing.
For Microsoft Windows OS, there are tons of video editor programs both free and proprietary (paid).
Windows users can for instance use the free software program VirtualDub (licensed under GPL license) to easily cut movie scenes from a video.

Unfortunately VirtualDub didn't have a Linux or BSD version so in my case I had to look for another soft.

VirtualDub running on Microsoft Windows XP Screenshot (Biomassa)

I consulted a friend of mine who recommended a video editor program called LiVES.

If you haven't done any video editing previously on Linux (like my case was), you will certainly be happy to try LiVES

Debian GNU / Linux LiVES video editor logo bootscreen shot

LiVES can extract only sound from videos, cut selected parts (frames) from videos and do plenty of other nice stuff. It is just great piece of software for anyone, who needs to do simply (newbie) video editting.

With LiVES even an amateur video editor like me could, immediately learn how to chop a movie scenes

Screenshot opened video for editting with LiVES Linux movie editor  Debian Squeeze Linux shot

To master the basics and edit one video in FLV format it took me about 1 hour of time, as in the beginning it was confusing to get confortable with the program scenes selector.

One downside of LiVES it failure to open a FLV file I wanted to edit.
In order to be able to edit the flv movie hence I first had to convert the FLV to AVI or MPEG, as this two (video multimedia formats) are supported by LiVES video editor.

After completing my video scenes chopping to the AVI file I had to convert back to FLV.

In order to complete the convertion between FLV to AVI format on my Debian Linux, I used a program called avidemux

Avidemux has a nice GUI interface and also like Lives has support for video editting, though I have never succesfully done any video edits with it.

Avidemux IMHO is user (completely intuitive). To convert the FLV to AVI, all I had to do was simply open the file FLV file, press (CTRL+S) select my FLV video file format and select the output file extension format to be AVI.

Further on, used LiVES to cut my desired parts from my video of choice. Once the cuts were complete I saved the new cutted version of video to AVI.
Then I needed the video again in FLV to upload it in Joomla, so used ffmpegcommand line tool to do the AVI to FLV file converstion, like so:

hipo@noah:~$ /usr/bin/ffmpeg -i my_media_file.avi my_video_file.flv

Hope this article helps someone aiming to do basic video editting on Linux with LiVES and just like needed FLV to AVI and AVI to FLV convertions.

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Tip: Quick Note taking on GNU / Linux and FreeBSD from terminal or console

Posted: 07 May 2012 11:13 AM PDT

I believe, the quickest way to take notes on Linux and BSD and later view the notes is to use the command line.
A very easy simple way to keep record of various short notes is just to use a simple text editor like (vim) and store each note in a separate file in lets say ~/notes/ directory.
Actually, I’m using this way to take notes and store sensitive info for various important information I need for further reference, since 5 years or so..
Opening a new text editor for each note and then doing cd ~/notes/; ls |grep -i ‘string’ is a bit time consuming.
Fortunately there is a quick two shell functions hack that shortens time for note taking. The following two bash functions has to be added in ~/.bashrc:

n() {
vim ~/notes/"$*".txt
}
nls() {
ls {
ls -c ~/notes/ | grep "$*"
}

Copy / Paste this two functions in the beginning or the end of ~/.bashrc in order to use them.

Also if ~/notes directory is not existing, yet create it:

hipo@noah:~$ mkdir notes

To make the two new input functions active across opened bash shells on console or terminal either re-login or reread the .bashrc by “sourcing it”, e.g.

hipo@noah:~$ source ~/.bashrc

Afterwards, note taking becomes a piece of cake to store a new note with login credentials (user/password) for a new registration to a random named website, type something like:

hipo@noah:~$ n my_website_name-user-pass

This will open for editting ~/.notes/my_website_name-user-pass.txt, type the new desired note content and do save and exit from vim (press esc and type :x !.

Then to get a quick list of all previously stored notes use:

hipo@noah:~$ nls website
my_website_name-user-pass.txt

If you already have a directory containing subdirectories with various taken notes (like me), you will need to use an improved version nls written by Jason Ryan, the nls improved is like this:

nls () { tree -CR --noreport ~/notes | awk '{
if ((NR >) gsub(/.txt/,"")); if
(NF==1) print $1; else if (NF==2)
print $2; else if (NF==3)
printf " %s\n", $3}';
}

This two functions, were not my creation but was suggested in Linux Magazine issue 135 article entitled Command-line task managers and note-taking tools written by Dmitri Popov.

Hope this two functions, will be helpful to console geeks out there.

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Browse the web graphically in text console TTYs with w3m-img and links2 on Debian, Ubuntu, Fedora and CentOS Linux

Posted: 05 May 2012 12:27 PM PDT

links2 (links console graphics) www browser logo picture

Lately, I'm starting to use my tty consoles more and more. Most of the people should be probably aware of the existence of lynx, elinks and w3m text browsers enabling the console geeks to browse or debug web pages in plain text mode.

Anyhow, for people who did not used one of the aforementioned browsers to text brose the net I warmly suggest you give them a try. A good review on 'em is in one of my  previous post – Text mode console browsing with lynx, elinks, w3m and links text browsers

For people dedicated to only use console and text mode console on their Personal Computer, simply installing and using this text browsers will not allow you to view any images tags in the html.

Nowdays one of the reasons many people would decide not to use console for web is because they want to see pictures. Hence I believe by having the opportunity to have almost fully functional text browsing in Linux cosnole /  terminal many might choose not to bother with heavy resource consuming desktop browsers like Firefox, Google Chrome, Opera etc..

Another good reason why you might want to use a console browser instead of its Desktop resource monsters, would be improved efficiency of work. It is a well evident fact keyboard access to commands is always faster than mouse and GUI!

Besides that, I'm convinced there should be many hard core geeks out there, who still can happily live without Macromedia Flash ads and Videos in Web. For this group of users having support for graphical browsing in console is also a must.
Following my previous thoughts there should be many people who doesn't have a specific requirement for GUI programs but still use (mutt, ssh, vim, mpg321, zgv etc.).

I'm sure there are plenty of this people who do most of their work in text console and use the X windows server in conjunction with mimalistic graphical environment like (DropBox, XFCE …) for the one and only reason to view  pictures embedded in web pages.

I'm one of all this guys prior mentioned, keen on console tty browsing. Therefore while checking the available console browsers few days ago, I've stumbled on a text console w3m browser capable of displaying website with images in console called w3m-img.

w3m-img is displays pictures in web over a plain console tty or in X terminals (mlterm, xterm etc.).

Here is the description returned by apt-cache show w3m-img

debian:~# apt-cache show w3m-img|grep -i description -A 3
Description: inline image extension support utilities for w3m
w3m-img provides some utilities to support inline images for w3m
on terminal emulator in X Window System environments and Linux
framebuffer.

w3m-img doesn't rely on svgalib for displaying the pictures, but comes with its own written console image display & rendering library called w3mimgdisplay. – /usr/lib/w3m/w3mimgdisplay.

One w3m-img pre-requirement in order to be able to display pictures in plain text console ttys is to have the Linux kernel framebuffer enabled..

Actually, framebuffer is enabled by default on latest stable Debian and derivatives as well as on most other Linux releases as of time of writing.
Framebuffer is also active on other RPM based distros (Fedora, CentOS, SuSE) etc.

The Frambebuffer on or off is controlled via some directives added in grub or lilo configuration files – (depending on the installed boot loader).

Some people can only boot their PCs with the framebuffer kernel support switched off at boot time or the system will not boot Linux at all.
Unfortunately this unlucky ones, would not be able to use the picture rendering w3m-img capabilities but don't be desperate, there is hope :)

For people who can't run their Linux distro with a framebuffer kernel support enabled there is a custom hacked version of linksconsole text browser called links-graphic. links-graphic supports both console graphical text browsing using the framebuffer or alternatively svgalib as a console graphics render machine.

I used to be actively using links-graphics WWW browser quite often about 8 years ago and just remembering it brings me good memories of the good old console "hacking" years :)

Anyways, w3m-img packaged version is currently available for both rpm and deb based Linux distributions. Here is how to install on both.

1.Install and use w3m-img on Debian, Ubuntu, Mint Linux-es

debian:~# apt-get --yes install w3m-img
....

This should install w3m-img, if of course there is already no previous install of w3m package on the system.

In case you have the w3m deb installed, you will have to first remove the existing w3m installed version before installing the w3m-img package, otherwise you will probably end up with an installation conflict (at least I got such a dependency conflict while apt-getting). Probably the conflict would never occur if aptitude install w3m-img is used instead of apt ….

Usage of w3m-img is exactly the same as using the w3m text only browser version. Below is a screenshot example of w3m-img in action:

debian:~# w3m http://images.google.com

w3m-img text (console) browsing images.google.com screenshot

Jesus Christ Pantocrator Orthodox icon google image search screenshot Debian Squeeze Linux

As you can see in the upper screenshots w3m-img displays pictures pretty nice, whether even images.google.com search functionality works fine.

Generally IMHO a lot of pages looks cool with w3m-img.
Some elements placement during rendering, comes at odd positions but this is normal, since original w3m text browser doesn't have any support for Javascript 1 / 2.

For those people who would like to have both javascript basic support and images in a plain text console browsing you, again you will have to compile links2 WWW browser from source manually with svgalib support enabled.

2. Installing w3m-img to text-browse with images on Fedora, CentoS, RHEL, Redhat etc.

[root@centos ~]# yum -y install w3m-img
....

A very cool thing of w3m graphical console browser is it support  most major image formats including animated GIF files :)

The way animated GIFs are viewed is very old school, here is a notice extracted from README.img contained in the pack.
 

Notice
If you want to see GIF animation, please hit a suitable key, such
as 'h', 'l', etc., repeatedly, because a frame is rewritten
according to the re-drawing demand from w3m.
Some code in w3mimg/fb/fb.c was originally written by Mr. Yamasaki.

http://www.sainet.or.jp/~yamasaki/download/fb-sample.tar.gz

As one can read in order to see an animated GIF file with w3m you will have to keep pumping the h or l key or Enter key :D :D :D (like a nintendo game ain't it?)

Here is the also the complete list of Supported browser features mentioned in README.img
 

Support

* Display inline image (GIF,PNG,JPEG, etc.) on terminals
(xterm,rxvt, etc.) of X11 or Linux framebuffer device.
* Support inline image of img tag.
Support of attributes "width", "height", and "align".
* Direct display of image file which header is "Content-type: image/*"
* Support of
tag.
Support of attributes "shape" and "coords" of
tag.
* Support of an attribute "ismap" of img tag.
"w3m" adds coordinate of the cursor as ?, to url, and sends url.
* Support of an attribute "type=image" of img tag.
"w3m" sends coordinate of the cursor as .x=&.y=.
* Asynchronous loading of image files.
* Using cache of image file as pixmap.
* Support of GIF animation when use GdkPixbuf.

Something else which I find worthy to mention is the browser behaviour, whether a webpage has Adobe Flash .swf or .flv files embedded. If such files are contained in website source code, they will be simply ignored and the w3m keeps running stable (no strange flash crashes! hooray!).

While website with flash is opened in w3m, Adobe Flash's field on the screen shows either a blank rectangle or an empty square (depending on the site embedded flash banner dimensions and form).

W3m-Img text web browser with picture viewing support adobe flash enabled youtube.com opened screenshot

Stability of w3m in opening flash website is something really nice. I say this because I still remember how terrible the situation with links with svgalib support compiled in used to be. I remember back in the day with links2 most "flash enabled" websites lead the browser to a ugly core dump.

3. Install and use links2 on Debian and derivatives Linux to browse in console graphically with javascript support

As aforementioned, there is a hacked version of links browser called links-graphics
This hacked version is available as a package within Debian, Ubuntu and presumably most if not all of the rest deb based Linux repos.

On Fedora and the other RPM family Linuces links-graphics, should be downloaded separately as rpm and installed and is inavailable through default rpm repositories.

On Debian distros links-graphics is available by installing links2.
debian:~# apt-get install --yes links2
....

Later to start links2 in graphics mode in lets say tty1 on a machine booted its kernel with framebuffer support, type:

debian:~# links2 -driver fb http://images.google.com

Actually links2 looks, way better in console than w3m but this is quite normal, as links is way more "user friendly GUI text browser".

For those, using their console ttys without framebuffer enabled you can alternatively run links2 with its svgalib graphics support like so:

debian:~# links2 -driver svgalib -mode 320x200x16 http://images.google.com

links graphics / xlinks images in X window on Debian GNU / Linux screenshot

Note that the svgalib driver is not working on my machine, as my Linux kernel framebuffer is already enabled. Probably if I want to use links2 through  svgalib I will have to reboot and boot machine with framebuffer kernel support switched off…

links2 also supports X window graphics and is a great for Graphical environment WWW browser substitute to CPU intensive Iceweasel / Firefox or Google Chrome.

Links2 can be also used as a default browser in X windows (GUI) with any graphic manager. In my view it is   perfect web browser  for scientists and people who does not need support for Adobe Flash Player or HTML5 standards.

To use links in XFCE or GNOME Desktop env, the quickest way is to prepare new Application Launcher to run command:

debian:~# links2 -g

Google Images links2 graphics in GNOME desktop env screenshot

It is useful to use a quick alias to links -g in my ~/.bashrc in order to allow easier browsing from console by typing xlinks someurladdress.com

If you want to add this xlinks shell alias  exec:

debian:~# echo 'alias xlinks='links2 -g $1' >> ~/.bashrc

4. Install links with graphics console support on Fedora, CentOS and RHEL

[root@fedora ~]# cd /usr/local/src
[root@fedora src]# wget -q http://jakub.horky.net/rpm/links/links-2.1pre15-2/links-2.1pre15-2.i386.rpm
[root@fedora src]# rpm -ivh --nodeps links-2.1pre15-2/links-2.1pre15-2.i386.rpm
Preparing... ########################################### [100%]
Installing... ########################################### [100%]

If you get some errors with missing libraries after installing and launching links2, try to resolve them by manually linking them with ln cmd or look for the library package rpm versions and install them via yum. Another way is to fetch the links2 source from Links2 official website links.twibright.com and build from source.

Since the last time in 8 years ago I used links2,  it evolved a lot. The version now did not crash as before with flash websites are viewed.  Generally Links2 now is way more  stable.
To sum it up most people, will probably want to use Links2 for console graphical browsing as the speed and support for HTML and Javascript and web site formatting is way advanced than w3m-img

I haven't compared the speed of opening pages, but since w3m-img is html and graphics render is more simple than xlinks I suppose at some occasions w3m-img will be faster in site rendering.
However still links2 performs really light fast and its web page opening time is swift and more than good.. If xlinks opening performance is compared to most (if not all) traditional desktop browsers used nowdays Links2 will definitely beat them.

A good links2 application instead of a traditional desktop browser is also for people who aim at  improving website browsing time.

I haven't thoroughfully enough, researched on other text console grahic browser alternatives programs. If I miss something and you know amy other better ones please let me know.

Wish you a Happy Browsing ;)

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Text Monitoring of connection server (traffic RX / TX) business in ASCII graphs with speedometer / Easy Monitor network traffic performance

Posted: 04 May 2012 07:02 AM PDT

While reading some posts online related to MS-Windows TcpViewnetwork traffic analyzing tool. I've came across very nice tool for tracking connection speed for Linux (Speedometer). If I have to compare it, speedometer is somehow similar to nethogs and iftop bandwidth network measuring utilities .

What differentiates speedometer from iftop / nethogs / iptraf is it is more suitable for visualizing a network file or data transfers.
The graphs speedometer draws are way easier to understand, than iftop graphs.

Even complete newbies can understand it with no need for extraordinary knowledge in networking. This makes Speedometer, a top tool to visually see the amount of traffic flowing through server network interface (eth0) … (eth1) etc.

What speedometer shows is similar to the Midnight Commander's (mc) file transfer status bar, except the statistics are not only for a certain file transfer but can show overall statistics over server passing network traffic amount (though according to its manual it can be used to also track individual file transfers).

The simplicity for basic use makes speedometer nice tool to track for network congestion issues on Linux. Therefore it is a  must have outfit for every server admin. Below you see a screenshot of my terminal running speedometer on a remote server.

Speedometer ascii traffic track server network business screenshot in byobu screen like virtual terminal emulator

1. Installing speedometer on Debian / Ubuntu and Debian derivatives

For Debian and Ubuntu server administrators speedometer is already packaged as a deb so its installation is as simple as:

debian:~# apt-get --yes install speedometer
....

2. Installing speedometer from source for other Linux distributions CentOS, Fedora, SuSE etc.

Speedometer is written in python programming language, so in order to install and use on other OS Linux platforms, it is necessery to have installed (preferably) an up2date python programming language interpreter (python ver. 2.6 or higher)..
Besides that it is necessary to have installed the urwid -( console user interface library for Python) available for download via excess.org/urwid/

 

Hence to install speedometer on RedHat based Linux distributions one has to follow these steps:

a) Download & Install python urwid library

[root@centos ~]# cd /usr/local/src
[root@centos src]# wget -q http://excess.org/urwid/urwid-1.0.1.tar.gz
[root@centos src]# tar -zxvvf urwid-1.0.1.tar.gz
....
[root@centos src]# cd urwid-1.0.1
[root@centos urwid-1.0.1]# python setup.py install
running install
running build
running build_py
creating build
creating build/lib.linux-i686-2.4
creating build/lib.linux-i686-2.4/urwid
copying urwid/tests.py -> build/lib.linux-i686-2.4/urwid
copying urwid/command_map.py -> build/lib.linux-i686-2.4/urwid
copying urwid/graphics.py -> build/lib.linux-i686-2.4/urwid
copying urwid/vterm_test.py -> build/lib.linux-i686-2.4/urwid
copying urwid/curses_display.py -> build/lib.linux-i686-2.4/urwid
copying urwid/display_common.py -> build/lib.linux-i686-2.4/urwid
....

b) Download and install python-setuptools

python-setuptools is one other requirement of speedometer, happily on CentOS and Fedora the rpm package is already there and installable with yum:

[root@centos ~]# yum -y install python-setuptools
....

c) Download and install Speedometer

[root@centos urwid-1.0.1]# cd /usr/local/src/
[root@centos src]# wget -q http://excess.org/speedometer/speedometer-2.8.tar.gz
[root@centos src]# tar -zxvvf speedometer-2.8.tar.gz
.....
[root@centos src]# cd speedometer-2.8
[root@centos speedometer-2.8]# python setup.py install
Traceback (most recent call last):
File "setup.py", line 26, in ?
import speedometer
File "/usr/local/src/speedometer-2.8/speedometer.py", line 112
n = n * granularity + (granularity if r else 0)
^

While running the CentOS 5.6 installation of speedometer-2.8, I hit the
"n = n * granularity + (granularity if r else 0)
error.

After consultation with some people in #python (irc.freenode.net), I've figured out this error is caused due the outdated version of python interpreter installed by default on CentOS Linux 5.6. On CentOS 5.6 the python version is:

[root@centos ~]# python -V
Python 2.4.3

As I priorly said speedometer 2.8's minimum requirement for a python to be at v. 2.6. Happily there is quick way to update python 2.4 to python 2.6 on CentOS 5.6, as there is an RPM repository maintained by Chris Lea which contains RPM binary of python 2.6.

To update python 2.4 to python 2.6:

[root@centos speedometer-2.8]# rpm -Uvh http://yum.chrislea.com/centos/5/i386/chl-release-5-3.noarch.rpm[root@centos speedometer-2.8]# rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CHL[root@centos speedometer-2.8]# yum install python26

Now the newly installed python 2.6 is executable under the binary name python26, hence to install speedometer:

[root@centos speedometer-2.8]# python26 setup.py install
[root@centos speedometer-2.8]# chown root:root /usr/local/bin/speedometer
[root@centos speedometer-2.8]# chmod +x /usr/local/bin/speedometer

[root@centos speedometer-2.8]# python26 speedometer -i 1 -tx eth0

The -i will instruct speedometer to refresh the screen graphs once a second.

3. Using speedometer to keep an eye on send / received traffic network congestion

To observe, the amount of only sent traffic via a network interface eth0 with speedometer use:

debian:~# speedometer -tx eth0

To only keep an eye on received traffic through eth0 use:

debian:~# speedometer -rx eth0

To watch over both TX and RX (Transmitted and Received) network traffic:

debian:~# speedometer -tx eth0 -rx eth0

If you want to watch in separate windows TX and RX traffic while  running speedometer you can run in separate xterm windows speedometer -tx eth0 and speedometer -rx eth0, like in below screenshot:

Monitor Received and Transmitted server Network traffic in two separate xterm windows with speedometer ascii graphs

4. Using speedometer to test network maximum possible transfer speed between server (host A) and server (host B)

The speedometer manual suggests few examples one of which is:

How fast is this LAN?

host-a$ cat /dev/zero | nc -l -p 12345
host-b$ nc host-a 12345 > /dev/null
host-b$ speedometer -rx eth0

When I red this example in speedometer's manual, it wasn't completely clear to me what the author really meant, but a bit after when I thought over the example I got his point.

The idea behind this example is that a constant stream of zeros taken from /dev/zero will be streamed over via a pipe (|) to nc which will bind a port number 12345, anyone connecting from another host machine, lets say a server with host host-b to port 12345 on machine host-a will start receiving the /dev/zero streamed content.

Then to finally measure the streamed traffic between host-a and host-b machines a speedometer is started to visualize the received traffic on network interface eth0, thus measuring the amount of traffic flowing from host-a to host-b

I give a try to the exmpls, using for 2 test nodes my home Desktop PC, Linux running  arcane version of Ubuntu and my Debian Linux notebook.

First on the Ubuntu PC I issued
 

hipo@hip0-desktop:~$ cat /dev/zero | nc -l -p 12345
 

Note that I have previously had installed the netcat, as nc is not installed by default on Ubuntu and Debian. If you, don't have nc installed yet, install it with:

apt-get –yes install netcat

"cat /dev/zero | nc -l -p 12345" will not produce any output, but will display just a blank line.

Then on my notebook I ran the second command example, given in the speedometer manual:
 

hipo@noah:~$ nc 192.168.0.2 12345 > /dev/null

Here the 192.168.0.2 is actually the local network IP address of my Desktop PC. My Desktop PC is connected via a normal 100Mbit switch to my routing machine and receives its internet via  NAT. The second test machine (my laptop), gets its internet through a WI-FI connection received by a Wireless Router connected via a UTP cable to the same switch to which my Desktop PC is connected.

Finally to test / get my network maximum thoroughput I had to use:

hipo@noah:~$ speedometer -rx wlan0

Here, I  monitor my wlan0 interface, as this is my (laptop) wireless card interface over which I have connectivity to my local network and via which through the the WI-FI router I get connected to the internet.

Below is a snapshot captured showing approximately what is the max network thoroughput from:

Desktop PC -> to my Thinkpad R61 laptop

Using Speedometer to test network thorougput between two network server hosts screenshot Debian Squeeze Linux

As you can see in the shot approximately the maximum network thoroughput is in between:
2.55MB/s min and 2.59MB/S max, the speed is quite low for a 100 MBit local network, but this is normal as most laptop wireless adapters hardly transfer traffic in more than 10 to 20 MBits per sec.

If the same nework thoroughput test is conducted between two machines both connected to a same 100 M/bit switch, the traffic should be at least a 8 MB/sec.

There is something, else to take in consideration that probably makes the provided example network thoroughput measuring a bit inaccurate. The fact that the /dev/zero content is stremed over is slowing down the zeroes sent over network because of the  pipe ( | ) use slows down the stream.

5. Using speedometer to visualize maximum writting speed to a local hard drive on Linux

In the speedometer manual, I've noticed another interesting application of this nifty tool.

speedometer can be used to track and visualize the maximum writing speed a hard disk drive or hard drive partition can support on Linux OS:

A copy paster from the manual text is as follows:

How fast can I write data to my filesystem? (with at least 1GB free)
dd bs=1000000 count=1000 if=/dev/zero of=bigfile &
speedometer bigfile

However, when I tried copy/pasting the example in terminal, to test the maximum writing speed to an external USB hard drive, only dd command was started and speedometer failed to initialize and display graphs of the file creation speed.

I've found a little "hack" that makes the man example work by adding a 3 secs sleep like so:

debian:/media/Expansion Drive# dd bs=1000000 count=1000 if=/dev/zero of=bigfile & sleep 3; speedometer bigfile

Here is a screenshot of the bigfile created by dd and tracked "in real time" by speedometer:

How fast is writting data to local USB expandable hard disk Debian Linux speedometer screenshot

Actually the returned results from this external USB drive are, quite high, the possible reason for that is it is connected to my laptop over an USB protocol verion 3.

6. Using Speedometer to keep an eye on file download in progress

This application of speedometer is mostly useless especially on Linux where it is used as a Desktop.

However in some occasions if files are transferred over ssh or in non interactive FTP / Samba file transfers between Linux servers it can come handy.

To visualize the download and writing speed of lets say FTP transferred .AVI movie (during the actual file transfer) on the download host issue:

# speedometer Download-Folder/What-goes-around-comes-around.avi

7. Estimating approximate time for file transfer

There is another section in the speedometer manual pointing of the program use to calculate the time remaining for a file transfer.

The (man speedometer) provided example text is:

How long it will take for my 38MB transfer to finish?
speedometer favorite_episode.rm $((38*1024*1024))

At first glimpse it hard to understand (like the other manual example). A bit of reasoning and I comprehend what the man author meant by the obscure calculation:

$((38*1024*1024))

This is a formula used in which 38 has to be substituted with the exact file size amount of the transferred file. The author manual used a 38MB file so this is why he put $((38* … in the formula.

I give it a try – (just for the sake to see how it works) with a file with a size of 2500MB, in below two screenshot pictures I show my preparation to copy the file and the actual copying / "real time" transfer tracking with speedometer's status percentage completion bar.

xterm terminal copy file and estimate file copying operation speed on linux with speedometer preparation

Two xterm terminals one is copying a file the other one uses speedometer to estimate the time remaining to complete the file transfer from expansion USB hard drive to my laptop harddrive

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How to check the IP address of Skype (user / Contacts) on GNU / Linux with netstat and whois

Posted: 03 May 2012 05:35 AM PDT

netstat check skype contact IP info with netstat Linux xterm Debian Linux

Before I explain how netstat and whois commands can be used to check information about a remote skype user - e.g. (skype msg is send or receved) in Skype. I will say in a a few words ( abstract level ), how skype P2P protocol is designed.
Many hard core hackers, certainly know how skype operates, so if this is the case just skip the boring few lines of explanation on how skype proto works.

In short skype transfers its message data as most people know in Peer-to-Peer "mode" (P2P)  - p2p is unique with this that it doesn't require a a server to transfer data from one peer to another. Most classical use of p2p networks in the free software realm are the bittorrents.

Skype way of connecting to peer client to other peer client is done via a so called "transport points". To make a P-to-P connection skype wents through a number of middle point destinations. This transport points (peers) are actually other users logged in Skype and the data between point A and point B is transferred via this other logged users in encrypted form. If a skype messages has to be transferred  from Peer A (point A) to Peer B (Point B) or (the other way around), the data flows in a way similar to:

 A -> D -> F -> B

or

B -> F -> D -> A

(where D and F are simply other people running skype on their PCs).
The communication from a person A to person B chat in Skype hence, always passes by at least few other IP addresses which are owned by some skype users who happen to be located in the middle geographically between the real geographic location of A (the skype peer sender) and B (The skype peer receiver)..

The exact way skypes communicate is way more complex, this basics however should be enough to grasp the basic skype proto concept for most ppl …

In order to find the IP address to a certain skype contact – one needs to check all ESTABLISHED connections of type skype protocol with netsat within the kernel network stack (connection) queue.

netstat displays few IPs, when skype proto established connections are grepped:

noah:~# netstat -tupan|grep -i skype | grep -i established| grep -v '0.0.0.0'
tcp 0 0 192.168.2.134:59677 212.72.192.8:58401 ESTABLISHED 3606/skype
tcp 0 0 192.168.2.134:49096 213.199.179.161:40029 ESTABLISHED 3606/skype
tcp 0 0 192.168.2.134:57896 87.120.255.10:57063 ESTABLISHED 3606/skype

Now, as few IPs are displayed, one needs to find out which exactly from the list of the ESTABLISHED IPs is the the Skype Contact from whom are received or to whom are sent the messages in question.

The blue colored IP address:port is the local IP address of my host running the Skype client. The red one is the IP address of the remote skype host (Skype Name) to which messages are transferred (in the the exact time the netstat command was ran.

The easiest way to find exactly which, from all the listed IP is the IP address of the remote person is to send multiple messages in a low time interval (let's say 10 secs / 10 messages to the remote Skype contact).

It is a hard task to write 10 msgs for 10 seconds and run 10 times a netstat in separate terminal (simultaneously). Therefore it is a good practice instead of trying your reflex, to run a tiny loop to delay 1 sec its execution and run the prior netstat cmd.

To do so open a new terminal window and type:

noah:~# for i in $(seq 1 10); do \
sleep 1; echo '-------'; \
netstat -tupan|grep -i skype | grep -i established| grep -v '0.0.0.0'; \
done

-------
tcp 0 0 192.168.2.134:55119 87.126.71.94:26309 ESTABLISHED 3606/skype
-------
tcp 0 0 192.168.2.134:49096 213.199.179.161:40029 ESTABLISHED 3606/skype
tcp 0 0 192.168.2.134:55119 87.126.71.94:26309 ESTABLISHED 3606/skype
-------
tcp 0 0 192.168.2.134:49096 213.199.179.161:40029 ESTABLISHED 3606/skype
tcp 0 0 192.168.2.134:55119 87.126.71.94:26309 ESTABLISHED 3606/skype
...

You see on the first netstat (sequence) exec, there is only 1 IP address to which a skype connection is established, once I sent some new messages to my remote skype friend, another IP immediatelly appeared. This other IP is actually the IP of the person to whom, I'm sending the "probe" skype messages.
Hence, its most likely the skype chat at hand is with a person who has an IP address of the newly appeared 213.199.179.161

Later to get exact information on who owns 213.199.179.161 and administrative contact info as well as address of the ISP or person owning the IP, do a RIPE  whois

noah:~# whois 213.199.179.161
% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See http://www.ripe.net/db/support/db-terms-conditions.pdf

% Note: this output has been filtered.
% To receive output for a database update, use the "-B" flag.
% Information related to '87.126.0.0 - 87.126.127.255'
inetnum: 87.126.0.0 - 87.126.127.255
netname: BTC-BROADBAND-NET-2
descr: BTC Broadband Service
country: BG
admin-c: LG700-RIPE
tech-c: LG700-RIPE
tech-c: SS4127-RIPE
status: ASSIGNED PA
mnt-by: BT95-ADM
mnt-domains: BT95-ADM
mnt-lower: BT95-ADM
source: RIPE # Filteredperson: Lyubomir Georgiev
.....

Note that this method of finding out the remote Skype Name IP to whom a skype chat is running is not always precise.

If for instance you tend to chat to many people simultaneously in skype, finding the exact IPs of each of the multiple Skype contacts will be a very hard not to say impossible task.
Often also by using netstat to capture a Skype Name you're in chat with, there might be plenty of "false positive" IPs..
For instance, Skype might show a remote Skype contact IP correct but still this might not be the IP from which the remote skype user is chatting, as the remote skype side might not have a unique assigned internet IP address but might use his NET connection over a NAT or DMZ.

The remote skype user might be hard or impossible to track also if skype client is run over skype tor proxy for the sake of anonymity
Though it can't be taken as granted that the IP address obtained would be 100% correct with the netstat + whois method, in most cases it is enough to give (at least approximate) info on a Country and City origin of the person you're skyping with.
 

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Facebook use in organizations harmful for company businesses – How to block facebook access to company or organization network on Linux routers

Posted: 02 May 2012 04:12 AM PDT

Facebook harms company and organization employee efficiency picture, Falling company efficiency diagram due to facebook employee use

I don't know if someone has thought about this topic but in my view Facebook use in organizations has a negative influence on companies overall efficiency!
Think for a while, facebook's website is one of the largest Internet based "people stealing time machine" so to say. I mean most people use facebook for pretty much useless stuff on daily basis (doesn't they ??). The whole original idea of facebook was to be a lay off site for college people with a lot of time to spend on nothing.
Yes it is true some companies use facebook succesfully for their advertising purposes and sperading the awareness of a company brand or product name but it is also true that many companies administration jobs like secretaries, accountants even probably CEOs loose a great time in facebook useless games and picture viewing etcetera.

Even government administration job positioned people who have access to the internet access facebook often from their work place. Not to mention, the mobility of people nowdays doesn't even require facebook to be accessed from a desktop PC. Many people employeed within companies, who does not have to work in front of a computer screen has already modern mobile "smart phones" as the business people incorrectly call this mini computer devices which allows them to browse the NET including facebook.

Sadly Microsoft (.NET) programmers and many of the programmers on various system platforms developers, software beta testers and sys admins are starting to adopt this "facebook loose your time for nothing culture". Many of my friends actively use the Facebook, (probably) because they're feeling lonely in front of the computer screen and they want to have interaction with someone.

Anyways, the effect of this constant fb use and aline social networks is clear. If in the company the employeed personal has to do work on the computer or behind any Internet plugged device, a big time of the use of the device is being 'invested' in facebook to kill some time instead of investing the same time for innovation within the company or doing the assigned tasks in the best possible way

Even those who use facebook occasionally from their work place (by occasionally I mean when they don't have any work to do on the work place), they are constantly distracted (focus on work stealed) by the hanging opened browser window and respectively, when it comes to do some kind of work their work efficiency drops severely.
You might wonder how do I know that facebook opened browser tab would have bad interaction with the rest of the employee work. Well let me explain. Its a well known scientifically proven fact that the human mind is not designed to do simultaneously multiple tasks (we're not computers, though even computers doesn't work perfect when simultaneous tasks are at hand.).
Therefore using facebook in parallel with their daily job most people nowdays try to "multi task" their job and hence this reflects in poor work productivity per employee. The chain result cause of the worsened productivity per employee is therefore seen in the end of the fiscal quarter or fiscal year in bad productivity levels, bad or worsened quality of product and hence to poor financial fiscal results.

I've worked before some time for company whose CEO has realized that the use of certain Internet resources like facebook, gmail and yahoo mail – hurts the employee work productivity and therefore the executive directors asked me to filter out facebook, GMAIL and mail.yahoo as well as few other website which consumed a big portion of the employees time …
Well apparantly this CEO was smart and realized the harm this internet based resources done to his business. Nowdays however many company head executives did not realize the bad effect of the heavy use of public internet services on their work force and never ask the system administrator to filter out this "employees efficiency thefts".

I hope this article, will be eventually red by some middle or small sized company with deteriorating efficiency and this will motivate some companies to introduce an anti-facebook and gmail use policy to boost up the company performance.

As one can imagine, if you sum up all the harm all around the world to companies facebook imposed by simply exposing the employees to do facebooking and not their work, this definitely worsenes the even severe economic crisis raging around …
The topic of how facebook use destroyes many businesses is quite huge and actually probably I'm missing a lot of hardmful aspects to business that can be imposed by just a simple "innocent facebook use", so I will be glad to hear from people in comments, if someone at all benefits of facebook use in an company office (I seriously doubt there is even one).

Suppose you are a company that does big portion of their job behind a computer screen over the internet via a Software as a Service internet based service, suppose you have a project deadline you have to match. The project deadline is way more likely to be matched if you filter out facebook.
Disabling access to facebook of employees and adding company policy to prohibit social network use and rules & regulations prohibiting time consuming internet spaces should produce good productivity results for company lightly.
Though still the employees can find a way to access their out of the job favourite internet services it will be way harder.
If the employee work progress is monitored by installed cameras, there won't be much people to want to cheat and use Facebook, Gmail or any other service prohibited by the company internal codex

Though this are a draconian measures, my personal view is that its better for a company to have such a policy, instead of pay to their emloyees to browser facebook….

I'm not aware what is the situation within many of the companies nowdays and how many of them prohibit the fb, hyves, google plus and the other kind of "anti-social" networks.
But I truly hope more and more organizations chairman / company management will comprehend the damages facebook makes to their business and will issue a new policy to prohibit the use of facebook and the other alike shitty services.

In the mean time for those running an organization routing its traffic through a GNU / Linux powered router and who'd like to prohibit the facebook use to increase the company employees efficiency use this few lines of bash code + iptables:

#!/bin/sh
# Simple iptables firewall rules to filter out www.facebook.com
# Leaving www.facebook.com open from your office will have impact on employees output ;)
# Written by hip0
# 05.03.2012
get_fb_network=$(whois 69.63.190.18|grep CIDR|awk '{ print $2 }');
/sbin/iptables -A OUTPUT -p tcp -d ${get_fb_network} -j DROP

Here is also the same filter out facebook, tiny shell script / blocks access to facebook script

If the script logic is followed I guess facebook can be disabled on other company networks easily if the router is using CISCO, BSD etc.
I will be happy to hear if someone did a research on how much a company efficiency is increased whether in the company office facebook gets filtered out. My guess is that efficiency will increase at least with 30% as a result of prohibition of just facebook.

Please drop me a comment if you have an argument against or for my thesis.

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This posting includes an audio/video/photo media file: Download Now

The Satanic roots of Metal and Rock Music genre – Two parts Christian movie exposing connection between Satanism and Metal music

Posted: 01 May 2012 05:28 AM PDT

Some long time ago a bit before I repent and believed in Jesus Christ as my Lord and Saviour, I've done quite an extensive research on the trustability of the Holy Bible and mostly the Church and Christian writtings. In that times, as an ex-metal head I had a profound interest if there is really a connection between Modern Hard Rock and Heavy Metal Music?

My research back then was quite thoroughful and I found plenty of proofs clearly showing a clear connection between most of the hard rock and heavy / death metal bands to satanism. I used to listen this anti-christian music for about 8 years repeatedly believing the message is not  really bad, even though subconsciously I knew something is not right with the music.

It was quite shocking to me to find that one of my favourite hard rock / psychedelic bands Led Zeppelin, The Beatles, The Doors, Rolling Stones etc. e, had a clear connection with Alester Crawley (a new age occultist magician and a forefather of modern satanism …).

Crawley was a completely insane person proclaiming himself under the alias "The Beast". This psycho travelled all around America, cursing people and cities and teaching people to worship evil. In other words the guy was a complete modern day anti-christ. I found in youtube few short 20 minute, movies exposing the relation between the new age ecumenistic beliefs and Crawley. Along with the musicians spoken about and their exposure to be a bible and God deniers, the movie explains why the message of this popular figures is anti-Christian in essence. This short few movies explains how this terrible guy Crawley become an inspirator of many of the today world popular played rock bands in most of the radio stations …


Satanism – The Root of Rock Music (part 1)


Satanism – The Root of Rock Music (part 2)

Another interesting documentary exposing some of the major pop and rock culture and musicians connection with satanism and the occult is They Sold Their Souls to the devil. The movie is again a short research on popular musicians, who openly say in their interviews they sold their souls for fame to the devil. . Many of the star musicians featured in this videos, even say openly they're possessed by evil spirits.


They Sold Their Souls to the devil part 1 of 3


They Sold Their Souls to the devil part 2 of 3


They Sold Their Souls to the devil part 3 of 3


They Sold Thir Souls to the devil part 4 of 4

Some people might think this is a joke non-serious, some crazy christian propaganda, but if you watch it without bias and analyze it nomatter if Christian or atheist you will see most of the things said in the video reflect the reality. Actually it's very sad reality, today's world has rapidly headed towards non-christianity, occult and satanism. Believe it or not, the elite in the world, we see daily on TV or hear on the Radio and read for as heroes in the newspapers has a strong connection with magicians, occult and fake spirituality. Many of them think loving evil is fun and okay but in fact it is a big lie we're said. As I've red someone says, once a lie is repeated many times it appears to sound like truth….
Anyways we should know Evil is evil and no good can come of worshipping the evil our ancestors and forefathers knew that pretty well and they used to teach us in a spirit to obey good and walk after good and not evil. Modern pop-rock culture teach us something else it teach us to go after the ways of dis-obeying satan took … Pitily our dying generation forgot that evil seeking will bring just evil and now systematically many  governments and medias are working seriously for  destroying the Christian moral and pureness hence by that we  seek to destroy ourselves hurrying towards our own destruction….

Lets hope God will be merceful and turn more people to him and unveil them the truth we read in the Holy Bible. I have hope more and more people will realize that we have to be living in a moderate and saintly way and not like the rock and pop stars shown in those videos. We should pray for each other and love each other and keep an eye on our children to let them not go the bad ways of witchcraft, unholiness and sinfulness  the modern pop – rock culture push us to.

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How to make screenshot in /dev/tty console on GNU / Linux – Taking picture JPEG / PNG snapshot of text console in systems without graphical environment

Posted: 30 Apr 2012 03:16 AM PDT

I'm used to making picture screenshots in GNOME desktop environment. As I've said in my prior posts, I'm starting to return to my old habits of using console ttys for regular daily jobs in order to increase my work efficiency. In that manner of thoughts sometimes I need to take a screenshot of what I'm seeing in my physical (TTY consoles) to be able to later reuse this. I did some experimenting and this is how this article got born.

In this post, I will shortly explain how a picture of a command running in console or terminal in GNU / Linux can be made

Before proceeding to the core of the article, I will say few words on ttys as I believe they might be helpful someone.
The abbreviation of tty comes after TeleTYpewritter phrase and is dating back somewhere near the 1960s. The TTY was invented to help people with impaired eyesight or hearing to use a telephone like typing interface.

In Unix / Linux / BSD ttys are the physical consoles, where one logs in (typing in his user/password). There are physical ttys and virtual vtys in today *nixes. Today ttys, are used everywhere in a modern Unixes or Unix like operating system with or without graphical environments.
Various Linux distributions have different number of physical consoles (TTYs) (terminals connected to standard output) and this depends mostly on the distro major contributors, developers or surrounding OS community philosophy.
Most modern Linux distributions have at least 5 to 7 physical ttys. Some Linux distributions like Debian for instance as of time of writting this, had 7 active by default physical consoles.
Adding 3 more ttys in Debian / Ubuntu Linux is done by adding the following lines in /etc/inittab:
 

7:23:respawn:/sbin/getty 38400 tty7
8:23:respawn:/sbin/getty 38400 tty8
9:23:respawn:/sbin/getty 38400 tty9

On some Linux distributions like Fedora version 9 and newer ones, new ttys can no longer be added via /etc/inittab,as the RedHat guys changed it for some weird reason, but I guess this is too broad issue to discuss ….

In graphical environments ttys are called methaphorically "virtual". For instance in gnome-terminal or while connecting to a remote SSH server, a common tty naming would be /dev/pts/8 etc.

tty command in Linux and BSDs can be used to learn which tty, one is operating in.

Here is output from my tty command, issued on 3rd TTY (ALT+F3) on my notebook:
 

noah:~# tty
/dev/tty3

A tty cmd output from mlterm GUI terminal is like so:
 

hipo@noah:~$ tty/dev/pts/9

Now as mentioned few basic things on ttys I will proceed further to explain how I managed to:

a) Take screenshot of a plain text tty screen into .txt file format
b) take a (picture) JPG / PNG screenshot of my Linux TTY consoles content

1. Take screenshot of plain text tty screen into a plain (ASCII) .txt file:

To take a screenshot of tty1, tty2 and tty3 text consoles in a txt plain text format, cat + a standard UNIX redirect is all necessery:
 

noah:~# cat /dev/vcs1 > /home/hipo/tty1_text_screenshot.txt
noah:~# cat /dev/vcs2 > /home/hipo/tty2_text_screenshot.txt
noah:~# cat /dev/vcs3 > /home/hipo/tty3_text_screenshot.txt

This will dump the text content of the console into the respective files, if however you try to dump an ncurses library like text interactive interfaces you will end up with a bunch of unreadable mess.
In order to read the produced text 'shots' onwards less command can be used …
 

noah:~# less /home/hipo/tty1_text_screenshot.txt
noah:~# less /home/hipo/tty2_text_screenshot.txt
noah:~# less /home/hipo/tty3_text_screenshot.txt

2. Take picture JPG / PNG snapshot of Linux TTY console content

To take a screenshot of my notebook tty consoles I had to first install a "third party program" snapscreenshot . There is no deb / rpm package available as of time of writting this post for the 4 major desktop linux distributions Ubuntu, Debian, Fedora and Slackware.
Hence to install snapscreenshot,I had to manually download the latest program tar ball source and compile e.g.:
 

noah:~# cd /usr/local/src
noah:/usr/local/src# wget -q http://bisqwit.iki.fi/src/arch/snapscreenshot-1.0.14.3.tar.bz2
noah:/usr/local/src# tar -jxvvvf snapscreenshot-1.0.14.3.tar.bz2

noah:/usr/local/src# cd snapscreenshot-1.0.14.3
noah:/usr/local/src/snapscreenshot-1.0.14# ./configure && make && make install
Configuring…
Fine. Done. make.
make: Nothing to be done for `all'.
if [ ! "/usr/local/bin" = "" ]; then mkdir –parents /usr/local/bin 2>/dev/null; mkdir /usr/local/bin 2>/dev/null; \
for s in snapscreenshot ""; do if [ ! "$s" = "" ]; then \
install -c -s -o bin -g bin -m 755 "$s" /usr/local/bin/"$s";fi;\
done; \
fi; \
if [ ! "/usr/local/man" = "" ]; then mkdir –parents /usr/local/man 2>/dev/null; mkdir /usr/local/man 2>/dev/null; \
for s in snapscreenshot.1 ""; do if [ ! "$s" = "" ]; then \
install -m 644 "$s" /usr/local/man/man"`echo "$s"|sed 's/.*\.//'`"/"$s";fi;\
done; \
fi

By default snapscreenshot command is made to take screenshot in a tga image format, this format is readable by most picture viewing programs available today, however it is not too common and not so standartized for the web as the JPEG and PNG.
Therefore to make the text console tty snapshot taken in PNG or JPEG one needs to use ImageMagick's convert tool. The convert example is also shown in snapscreenshot manual page Example section.

To take a .png image format screenshot of lets say Midnight Commander interactive console file manager running in console tty1, I used the command:
 

noah:/home/hipo# snapscreenshot -c1 -x1 > ~/console-screenshot.tga && convert ~/console-screenshot.tga console-screenshot.png

Linux text console tty mc screenshot with snapscreenshot terminal / console snapshotting program

Note that you need to have read/write permissions to the /dev/vcs* otherwise the snapscreenshot will be unable to read the tty and produce an error:
 

hipo@noah:~/Desktop$ snapscreenshot -c2 -x1 > snap.tga && convert snap.tga snap.pngGeometry will be: 1x2Reading font…/dev/console: Permission denied

To take simultaneous picture screenshot of everything contained in all text consoles, ranging from tty1 to tty5, issue:
 

noah:/home/hipo# snapscreenshot -c5 -x1 > ~/console-screenshot.tga && convert ~/console-screenshot.tga console-screenshot.png

Here is a resized 480×320 pixels version of the original screenshot the command produces:

All text Consoles tty1 to tty5 merged screenshot png image with snapscreenshot taken on Debian GNU / Linux

Storing a picture shot of the text (console) screen in JPEG (JPG) format is done analogously just the convert command output extension has to be changed to jpeg i.e.:
 

noah:/home/hipo# snapscreenshot -c5 -x1 > ~/console-screenshot.tga && convert ~/console-screenshot.tga console-screenshot.jpeg

I've also written a tiny wrapper shell script, to facilitate myself picture picture taking as I didn't like to type each time I want to take a screenshot of a tty the above long line.

Here is the wrapper script I wrote:
 

#!/bin/sh
### Config
# .tga produced file name
output_f_name='console-screenshot.tga';
# gets current date
cur_date=$(date +%d_%m_%Y|sed -e 's/^ *//');
# png output f name
png_f_name="console-screenshot-$cur_date.png";
### END Config
snapscreenshot -c$arg1 -x1 > $output_f_name && convert $output_f_name $png_f_name;
echo "Output png screenshot from tty1 console produced in";
echo "$PWD/$png_f_name";
/bin/rm -f $output_f_name;

You can also download my console-screenshot.sh snapscreenshot wrapper script here

The script is quite simplistic to use, it takes just one argument which is the number of the tty you would like to screenshot.
To use my script download it in /usr/local/bin and set it executable flag:
 

noah:~# cd /usr/local/bin
noah:/usr/local/bin# wget -q http://www.pc-freak.net/~bshscr/console-screenshot.sh
noah:/usr/local/bin# chmod +x console-screenshot.sh

Onwards to use the script to snapshot console terminal (tty1) type:
 

noan:~# console-screenshot.sh

I've made also mirror of latest version of snapscreenshot-1.0.14.3.tar.bz2 here just in case this nice little program disappears from the net in future times.

 

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