The linux command: dmidecode

The linux command dmidecode is a tool for dumping a computer's DMI.

# dmidecode -h
Usage: dmidecode [OPTIONS]
Options are:
 -d, --dev-mem FILE     Read memory from device FILE (default: /dev/mem)
 -h, --help             Display this help text and exit
 -q, --quiet            Less verbose output
 -s, --string KEYWORD   Only display the value of the given DMI string
 -t, --type TYPE        Only display the entries of given type
 -u, --dump             Do not decode the entries
 -V, --version          Display the version and exit

Let's see the option: -t.

# dmidecode -t -h
Invalid type keyword: -h
Valid type keywords are:
  bios
  system
  baseboard
  chassis
  processor
  memory
  cache
  connector
  slot

Now let's show you some infos about my old processor.

# dmidecode -t processor
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0x0004, DMI type 4, 32 bytes
Processor Information
 Socket Designation: SOCKET A
 Type: Central Processor
 Family: Other
 Manufacturer: AuthenticAMD
 ID: 62 06 00 00 FF FB 83 03
 Signature: Family 6, Model 6, Stepping 2
 Flags:
  FPU (Floating-point unit on-chip)
  VME (Virtual mode extension)
  DE (Debugging extension)
  PSE (Page size extension)
  TSC (Time stamp counter)
  MSR (Model specific registers)
  PAE (Physical address extension)
  MCE (Machine check exception)
  CX8 (CMPXCHG8 instruction supported)
  APIC (On-chip APIC hardware supported)
  SEP (Fast system call)
  MTRR (Memory type range registers)
  PGE (Page global enable)
  MCA (Machine check architecture)
  CMOV (Conditional move instruction supported)
  PAT (Page attribute table)
  PSE-36 (36-bit page size extension)
  MMX (MMX technology supported)
  FXSR (Fast floating-point save and restore)
  SSE (Streaming SIMD extensions)
 Version: AMD Athlon(TM) MP 1700+
 Voltage: 1.7 V
 External Clock: 133 MHz
 Max Speed: 2250 MHz
 Current Speed: 1466 MHz
 Status: Populated, Enabled
 Upgrade: Other
 L1 Cache Handle: 0x0009
 L2 Cache Handle: 0x000A
 L3 Cache Handle: Not Provided

Also you can use this format to read infos.

# dmidecode --type 0 --type 13 

The numbers tell what to read, see:

bios
system  1, 12, 15, 23, 32
baseboard  2, 10, 41
chassis  3
processor  4
memory  5, 6, 16, 17
cache  7
connector  8
slot  9

Deadlock make with Unity - Linux 32 and 64.

Another game for Linux users: Deadlock.
Also, the Windows and OSX users can play this game using the web browser with the Unity plugin.
Recommended:

- Intel Core-2-Quad 2.4GHz or similar
- 2 Go Ram
- DX9 3D video card such as Nvidia GTX280 or Radeon HD5850 or newer.

You need to have the GLIBCXX_3.4.11 under Linux OS.
Deadlock website

Vulnerability? google paypal facebook and internal ip

Do you have any idea about an Internal IP Address or a Private IP Address that too assigned for Multinational Companies? Yeah, today we are gonna discuss about Internal IP or Private IP address Disclosure.
Disclosure of an Internal IP like 192.168.*.* or 172.16.*.* , can really Impact? Most security researchers call it as "bull shit" vulnerability. But when it comes to impact calculation even if the server is behind a firewall or NAT, an attacker can see internal IP of the remote host and this may be used to further attacks.
Read more here.

Linux - Fedora and Android make read-only file system.

I don't know what is the problem with Linux - Fedora and Android OS.
After I put my USB cable seam Fedora make from write disk to read-only.
Maybe the Android when scan the device set to read-only.
So you can get some error like this when you use the chown command:

chown: changing ownership of ...: Read-only file system

That can be one big problem when you want to copy files on your tablet.
I found a solution, just use remount.

# mount -o rw,remount /media/disk

If you want to make read-only, use:

# mount -o ro,remount /media/disk

That will solve this issue.

News: Tips and tricks: recursive show images

The "Mastering OpenCV with Practical Computer Vision Projects" book is done and published!
Also: including a screenshot of each project...
This will be the main issue.
... to see the screenshot from each project
...and also to find a way for any file to use
Let's take the book and source code:

$ git clone git://github.com/MasteringOpenCV/code.git

Go to the main folder: $ cd code and use this:

code]$ ls 
Chapter1_AndroidCartoonifier     Chapter7_HeadPoseEstimation
Chapter2_iPhoneAR                Chapter8_FaceRecognition
Chapter3_MarkerlessAR            Chapter9_FluidInteractionUsingKinect
Chapter4_StructureFromMotion     LICENSE.txt
Chapter5_NumberPlateRecognition  README.md
Chapter6_NonRigidFaceTracking

If we use the tree Linux command the result will be:

.
|-- Chapter1_AndroidCartoonifier
|   |-- Cartoonifier_Android
|   |   |-- AndroidManifest.xml
|   |   |-- jni
|   |   |   |-- Android.mk
|   |   |   |-- Application.mk
|   |   |   `-- jni_part.cpp
|   |   |-- project.properties
|   |   |-- res
|   |   |   |-- drawable
|   |   |   |   `-- icon.png
|   |   |   `-- values
|   |   |       `-- strings.xml
|   |   `-- src
|   |       `-- com
|   |           `-- Cartoonifier
|   |               |-- CartoonifierApp.java
|   |               |-- CartoonifierView.java
|   |               `-- CartoonifierViewBase.java
|   |-- Cartoonifier_Desktop
|   |   |-- CMakeLists.txt
|   |   |-- ImageUtils.h
|   |   |-- ImageUtils_0.7.cpp
|   |   |-- cartoon.cpp
|   |   |-- cartoon.h
|   |   `-- main_desktop.cpp
|   |-- README.txt
|   `-- screenshot.png
|-- Chapter2_iPhoneAR

We need something to find the absolute path and give that to gthumb to run it.
First, find the screenshot:

 code]$ ls -d  $PWD/**/*.png
/home/free-tutorials/code/Chapter1_AndroidCartoonifier/screenshot.png
/home/free-tutorials/code/Chapter2_iPhoneAR/screenshot.png
/home/free-tutorials/code/Chapter3_MarkerlessAR/screenshot.png
/home/free-tutorials/code/Chapter4_StructureFromMotion/screenshot.png
/home/free-tutorials/code/Chapter5_NumberPlateRecognition/screenshot.png
/home/free-tutorials/code/Chapter6_NonRigidFaceTracking/screenshot.png
/home/free-tutorials/code/Chapter7_HeadPoseEstimation/screenshot.png
/home/free-tutorials/code/Chapter8_FaceRecognition/screenshot.png
/home/free-tutorials/code/Chapter9_FluidInteractionUsingKinect/screenshot.png

Now will run gthumb with all these images:

code]$ ls -d  $PWD/**/*.png | xargs gthumb 

ImageMagick resize with preserve aspect ratio.

ImageMagick is used to change images.
In this case, I will show how to resize images and preserve aspect ratio:
...with height: 600 pixels

convert  -resize x600 *.png

...with width: 600 pixels

convert  -resize 600x *.png

If you know more about ImageMagick send me one email.

Linus Torvalds - kernel 3.7 is now out.

From: Linus Torvalds <torvalds <at> linux-foundation.org>

Subject: Linux 3.7

Newsgroups: gmane.linux.kernel

Date: 2012-12-11 03:59:50 GMT (9 hours and 45 minutes ago)

Whee. After an extra rc release, 3.7 is now out. After a few more trials at fixing things, in the end we ended up reverting the kswapd changes that caused problems. And with the extra rc, I had decided to risk doing the buffer.c cleanups that would otherwise have just been marked for stable during the next merge window, and had enough time to fix a few problems that people found there too. There's also a fix for a SCSI driver bug that was exposed by the last-minute workqueue fixes in rc8. Other than that, there's a few networking fixes, and some trivial fixes for sparc and MIPS. Anyway, it's been a somewhat drawn out release despite the 3.7 merge window having otherwise appeared pretty straightforward, and none of the rc's were all that big either. But we're done, and this means that the merge window will close on Christmas eve. Or rather, I'll probably close it a couple of days early. For obvious reasons. It's the main commercial holiday of the year, after all. So aim for winter solstice, and no later. Deal? And even then, I might be deep into the glögg. Linus

Read more here.

Simple convert images using ImageMagick - convert features

Can be done by using ImageMagick.This is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats over 100. Using ImageMagick let you resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.
Install the software under Fedora:

# yum install  ImageMagick 

Convert an image from one format to another. In this case jpeg.

$ convert *.png *.jpg

$ mogrify -format png *.jpg  

Read more about this software here.

News: Unusual commands in linux : pv

Today I will speak about pv command.
Pipe viewer - pv is a terminal-based tool for monitoring the progress of data through a pipeline written by Andrew Wood
To install pv on Fedora or CentOS do this:

$ sudo yum install pv

You can read the man file to get more help:

man pv

The result is:

NAME
       pv - monitor the progress of data through a pipe

SYNOPSIS
       pv [OPTION] [FILE]...
       pv [-h|-V]

DESCRIPTION
       pv  allows  a  user  to see the progress of data through a pipeline, by
       giving information such as time  elapsed,  percentage  completed  (with
       progress  bar),  current  throughput  rate, total data transferred, and
       ETA.

       To use it, insert it in a pipeline  between  two  processes,  with  the
       appropriate  options.  Its standard input will be passed through to its
       standard output and progress will be shown on standard error.

Let's see some examples.
You can get precise time how long it will take.

$ pv voronoi.py | python 
 737B 0:00:00 [86.9kB/s] [==================================>] 100%

You can see how fast the computer reads from /dev/zero.

$ pv /dev/zero > /dev/null
1.1GB 0:00:05 [   2GB/s] [    <=>                                            ]

You can use the dialog to show a progress bar.
To do this you need to use -n arg.

$ (pv -n /dev/zero > /dev/null) 2>&1 | dialog --gauge "Please wait" 10 70 0

Make one simple kernel module using C programming language.

Today I will try to explain how to make a kernel module.
Basically, a kernel module it's one piece of code that can be loaded and unloaded into the kernel.
You can read about kernel modules from here.
Now, let's try to make a simple kernel module.
Writing your own module can be done if you know some basic rules.
First, about how to use modules.
Suppose you have a new module named kernelmoduletest.
How to load the module.
Just use this command in your module kernel folder:

#insmod kernelmoduletest.ko

Next, test the kernel module messages.
This can be done with:

#dmesg | tail

Also, you need to remove the kernel module.

$ rmmod kernelmoduletest 
ERROR: Removing 'kernelmoduletest': Operation not permitted

This means you need to have superuser rights. So use the sudo or su command.
Then use the rmmod command.
Know how to make the kernel module skeleton.
This is not very simple because you need to know many things about kernel and programming.
But you can try the test with some simple example like this example:
Create the c file named kernelmoduletest and add this source code:

#include <linux module.h="">
#include <linux kernel.h="">

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("kernelmoduletest");
MODULE_AUTHOR("Catalin George Festila/mythcat/catafest");

int init_module() {

    printk(KERN_INFO "Now I will initialize my  kernel module\n");

    printk(KERN_INFO "Test: Hello World !\n");

    return 0;
}

void cleanup_module() {

    printk(KERN_INFO "Bad!... kernel module unloaded.\n");
}</linux></linux>

Make a new file named Makefile.
Add this to tell how to compile the kernel module.

obj-m += kernelmoduletest.o
all:
 make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
 make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

Compile your kernel module
Just use make command.

# make
...
  Building modules, stage 2.
  MODPOST 1 modules
...
make[1]: Leaving directory `/usr/src/linux-headers-2.6.31-14-generic'

If you test your module using the commands from the top of this tutorial, you can see that:

[14694.779227] Now I will initialize my  kernel module
[14694.779233] Test: Hello World !
[15049.825605] Bad!... kernel module unloaded.

If you have already made kernel modules and the subject it's interesting for you, send me an email.
Thank you. Regards.

News: Tips and tricks: watch and cat.

Sometimes it is necessary to find solutions.
Today's example involves two Linux commands:
watch and cat
Here is a simple method by creating a script that returns an output:

while [ 1 ]; do cat /proc/meminfo; date; echo; sleep 1; done

Make this script executable and name it: meminfo.
The output is then processed by the command:

$ watch -d ./meminfo 

This simple method can be applied to other files ...

Using SL4A bash shell script to connect Linux with Android tablet .

Using Linux with Android OS is very simple.
I install the next two android application: sl4a_r6.apk and PythonForAndroid-r7b1.apk.
Use the PythonForAndroid-r7b1.apk just if you want to write some python scripts.
We can download it from here.
The first: sl4a_r6 it's used to write and run scripts like bash shell, HTML, Java, Python.
With this, the SL4A provides and make APIs available via JSON RPC calls.
The PythonForAndroid-r7b1 allow you to install python modules...
We can read more on this website.
Let's start with one simple bash shell script.
We will make a shell script to test the connection between Linux and Android tablet.
The connection will be through a wireless router that has opened the port through which the communication.
Tablet has Android 4.0.
We use the Linux command NC, see: nc command.
This is the script on the tablet and it will run first.

nc -l -p 7000

See the next image:

Button 1 - run the script
Button 2 - edit the script
Button 3 - save the script
Button 4 - remove the script
Use the next command with your IP on the Linux terminal.

nc xxx.xxx.xxx.xxx 7000

If you type something in your terminal you will see on a tablet.
The input from my linux terminal can be seen in the next image:

Ant this is the output on my tablet.

We can test multiple features of command nc.
I'm just curious if you have some new ideas on this subject.

News: New GTK3 theme make your Linux to look like an Android

The new GTK3 theme inspired by Android will make your Linux nicer.
reNIX Gnome Shell theme: [link]
reNIX (for Chrome/Chromium): [link]

News: About light laptop with your Linux distros.

ZaReason is launching a thin and light laptop called the UltraLap 430.
Linux computer builder has all the specs you’d expect from a modern ultrabook.
Prices start at $899 and it's available now from the ZaReason store.

Features:

• 14.1" HD (1366x768) Glossy LED Backlit Display
• 3rd Generation Intel Core Processor
• Intel HD 4000 Graphics
• Quick performance and power-on times with Solid State Disks
• HD Stereo Speakers
• 802.11 B/G/N WiFi included
• Bluetooth
• 3 in-1 card reader -- SD/MMC/MS supported
• 1.3 Megapixel HD webcam included
• Multi-gesture touchpad

Ports:

• HDMI port
• Gigabit Ethernet port
• Kensington lock port
• Headphone/Mic Jack
• 2 USB 3.0 ports
• 1 USB 2.0 port

Specs:

• Your choice of a variety of Open Source operating systems, like Fedora 17
• Battery Life: Up to 6 hrs
• Dimensions (WxDxH): 13.5in x 9.25in x .75in
• Weight: ~3.5 lbs

News: Google Translate Android can translate from pictures.

News about Google Translate Android.
Use camera to take a picture and brush text to translate - available on Android 2.3 and above.
Get instant translation results as you type.
Choose dialect preference for speech input.
Japanese handwriting now recognizes multiple characters at once.
Added access network state permission to check network availability when sending requests.
Try this on play.google.com

OpenGL Driver support for Linux and Windows.

NVIDIA has released a set of OpenGL 4.3 drivers for Windows and for Linux.
The driver support provides beta support for OpenGL 4.3 and GLSL 4.30 on capable hardware.
For Linux, the version number R304.15 is not the same with the drivers for Windows: R305.53.
All ARB extension specifications can be downloaded here: this page.
For OpenGL 4 capable hardware, these new extensions are provided: ARB_compute_shader ,ARB_multi_draw_indirect ,ARB_shader_image_size ,ARB_shader_storage_buffer_object
You can download all drivers from here.

Testing your disks using dd utility and time.

You can execute copies a large block of data to and from disk.

This will minimize disk caching.

Next is one example if our test system has 1GB of RAM.

It is easy ( 1GB = 250,000 blocks ).

$ time sh -c "dd if=/dev/zero of=bigfile bs=8k count=250000 && sync"
250000+0 records in
250000+0 records out
2048000000 bytes (2.0 GB) copied, 37.0113 s, 55.3 MB/s

real 0m40.910s
user 0m0.172s
sys 0m12.641s

It's very hard to argue with this dd test.

Using DIGITAL PEN CAMERA eheV1-USB-II with mplayer

It's not my camera, I take it just to try to make working on Linux OS.
This is the device.

The dmesg tell me about this camera:
uvcvideo: Found UVC 1.00 device USB2.0 Camera
If you want to see and not to take frames, then use :
mplayer tv:// driver=v4l2:width=640:height=480:device=/dev/video0 -vo null
You can try to take some frames. I use this:
mplayer tv:// -frames 10 -tv fps=20:driver=v4l2:width=640:height=480:device=/dev/video0 -vo jpeg
The result is ten frames.
On this image I draw one line to see how working default.

And using the zoom ...

Working with old video card and also old Ogre 3D engine and Blender 3D.

I make today a new tutorial about the trips and tricks with Ogre 3D engine using Blender 3D.
If you want to see this, you can go on the tutorials part from my site.
This is the just a result of my simple example.
The result is shown in next image sample.

News: Programming with google-blocky

It's fun. You can try or your children.
Blockly is a web-based, graphical programming language. Users can drag blocks together to build an application. No typing required.

You can see more on google project.

Show large image like thumbnails in firefox using greasemonkey

Today I focused on a problem you often encounter.

We have a web folder containing a series of large image files. We want to see the folder that contains but would be difficult to download all the images and then view them search to find a picture of us.

I installed Greasemonkey addon and I began to study how it works.

I don't have experience with javascript programming.

I still managed to make the script below:

// ==UserScript==
// @name        show-image
// @namespace   show-image
// @description show images from files
// @include     http://*
// @version     0.1
// ==/UserScript==
var elements = document.getElementsByTagName("a");
  for (var i=0; (anchor=elements[i]); i++) {
   src = anchor.getAttribute("href");
  if (src.indexOf('.gif') > -1 || src.indexOf('.jpg') > -1 || src.indexOf('.JPG') > -1 || src.indexOf('.jpeg') > -1)
  {
    img = document.createElement('img');
    img.setAttribute('src',src);
    img.style.width='10%';
    anchor.appendChild(img);
   }
  }

You can add to show the png file by adding in the if condition in the script :

src.indexOf('.png') > -1 || src.indexOf('.PNG') > -1

I hope to help you.

News: Working with python , opengl and ARB ...

Today I test a simple script that uses the OpenGL ARB "Architecture Review Board".
The script is very simple and can be found on my graphic-3d.blogspot.com.
I make this with Python 2.6.4 , pyopengl module.

Fedora online defragmenter for ext4 filesystem

The tool is e4defrag.
The man page tells us: reduces fragmentation of extent based file.
The file targeted by e4defrag is created on ext4 filesystem made with "-O extent" option (see mke2fs(8)). The targeted file gets more contiguous blocks and improves the file access speed.
Let's try this tool.
You can try under root account this:
# e4defrag -test -cv /home/your_user/
The final result on my account is :
Total/best extents 170276/165520 Fragmentation ratio 0.03% Fragmentation score 0.24 [0-30 no problem: 31-55 a little bit fragmented: 55- needs defrag]
Also, you have to run e4defrag with the -test parameter for now, since it isn't a fully tested version.

The LightScribe - without labels and handwriting.

LightScribe is an innovative technology that uses a special disc drive, special media, and label-making software to burn labels directly onto CDs and DVDs.
Download the packages from here.
Use the root account and install this packages :

# rpm -ivh lightscribe-1.18.24.1-linux-2.6-intel.rpm 
Preparing...                ########################################### [100%]
   1:lightscribe            ########################################### [100%]
# rpm -ivh lightscribeApplications-1.18.15.1-linux-2.6-intel.rpm 
Preparing...                ########################################### [100%]
   1:lightscribeApplicationswarning: group admin does not exist - using root%)
warning: group admin does not exist - using root
########################################### [100%]

The path application is /opt/SimpleLabeler/
See the files:

$ ll
total 332
drwxr-xr-x. 4 root wheel   4096 Feb 27 14:10 content
-rwxr-xr-x. 1 root wheel   2980 May 19  2010 launchBrowser.sh
drwxr-xr-x. 3 root wheel   4096 Feb 27 14:10 plugins
-rwxr-xr-x. 1 root wheel     43 May 19  2010 qt.conf
-rw-r--r--. 1 root root      16 May 19  2010 qttr.qm
-rwsr-xr-x. 1 root wheel 314088 May 19  2010 SimpleLabeler
-rw-r--r--. 1 root root      16 May 19  2010 simplelabelertr.qm

Run the SimpleLabeler, and you see this :

Insert the special media in the special disc drive with the face down.
This is a way to not use labels and handwriting.

G'MIC plug-in for GIMP.

GIMP is an acronym for GNU Image Manipulation Program and it has many capabilities.
One best feature is the plugins system. Plugins may be stored in different locations depending upon your distribution.
The author of G'MIC plug-in tell us: The G'MIC plug-in for GIMP proposes a set of various filters to apply on your images, including artistic effects, image denoising, and enhancement algorithms, 3D renderers, etc.. It is a quite large plug-in, integrating a lot of different effects.
You can download the G'MIC plug-in from here.
Unzip the file and go to the folder where is the gmic_gimp file.
Use this command to copy the file in the plug-ins folder.

$ cp  gmic_gimp ~/.gimp-2.6/plug-ins/

Once you have installed the plugin just restart the GIMP.
The G'MIC will work just if you have opened an image.
You can find it on menu: Filters-> G'MIC... Also, the G'MIC plug-in has available 284 filters.

Protect your root account.

I will present a solution to protect the root account, quite funny but still elegant.
You can read about the command trap using: man trap.
What is this command?
when the specified event will occur will execute the command specified.
In this case, it will receive signal respectively will execute one command - exit
The source code.

 protect()
 {
 echo "What is the secret ?"
 trap protect 2 20
 read -s resp
 if [ "$resp" != "asd" ]; then
 echo "Error!"
exit
fi
 }
 protect

The result will be leaving the root account if you do not answer the question correctly.
Now protect the file against unauthorized changes:

# chmod 700 /root/.bashrc

You can create using the example above, different ways to execute various commands.

Android ARM Assembly by Vikram Aggarwal

Today I read an interesting article about Android.
The article is written by the developers Vikram Aggarwal, a software engineer at Google.
This article - tutorial consists of a series on learning ARM assembly on Android.
Its subject is "...calling Assembly code from Android applications".
The tutorial contains the necessary source code and details for the reader to understand how it works.
For those who have never used Gas (GNU Assembler), this article is of interest much.
I wonder if there is anyone interested in the Fedora community to write Android applications.
This article can be read here.

Creating folders and documents with gdata module

Today I played with gdata python module.
The problem that I solved it:
creating folders and documents in your Gmail account.
First, you need to install the gdata module.
In fedora I used:

yum install python-gdata.noarch 

Here are the first lines of source code that creates a folder named test-fedora

Python 2.7.1 (r271:86832, Apr 12 2011, 16:16:18) 
[GCC 4.6.0 20110331 (Red Hat 4.6.0-2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import gdata.docs.service
>>> my=gdata.docs.service.DocsService()
>>> my.ClientLogin('your-account@gmail.com','your-password')
>>> my.CreateFolder('test-fedora')

I tried to automate the process of creating folders and I used a list and instruction for

>>> folders=['aaa','bbb','ccc']
>>> for f in folders:
...     my.CreateFolder(f)
... 

To create a document to write more lines of code.
This is because there are many types of documents

>>> new_entry = gdata.GDataEntry()
>>> new_entry.title = gdata.atom.Title(text='fedora-test')
>>> category = my._MakeKindCategory(gdata.docs.service.DOCUMENT_LABEL)
>>> new_entry.category.append(category)
>>> created_entry = my.Post(new_entry, '/feeds/documents/private/full')

Here's a simple solution to avoid loss of mail password.

>>> import getpass
>>> username = raw_input('Please enter your username: ')
Please enter your username: user1
>>> password = getpass.getpass()
Password: 
>>> print username
user1
>>> print password
pass1

I hope you will use this

The list of linux tutorials ...

The last time I wrote small tutorial for free-tutorials.org site.
These tutorials have covered several areas.
Here are targeting Linux.
The indication of a denial of service (DoS) attack...
How to display memory in real time on Linux system...
Change settings and passwords in Windows using Lin...
How to change bash custom prompt ?
How to use the import command to take screenshots?
Linux commands : "find" and the option "empty"
Create html file with bash script.
Simple bash script to create folders, files and im...
Using wget tool
error: dd: opening `/dev/sdb1': Permission denied...
error: 'memset' was not declared in this scope
Installing and configuring the Eclipse IDE - Googl...
How to set up an external webrowser on Eclipse IDE
Fedora - Install Skype
Modifying shortcuts keys on Bluefish 1.0.7
Fedora - How we can get movies from youtube.
Fedora 12 - How can we run one script when system ...
Linux Text-To-Speech Tutorial
Geany and regular expressions.
Yumex on Fedora
Assign keys on Linux.
I will try to write more tutorials about Linux...

Fedora 15 : Extracting rar files

The unrar package can be installed from here.
The unRAR utility is a freeware program, distributed with source code and developed for extracting, testing and viewing the contents of archives created with the RAR archiver version 1.50 and above.

unrar-3.9.9-1.fc15.x86_64.rpm  
unrar-3.9.9-1.fc15.i686.rpm  
unrar-3.9.9-1.src.rpm  
unrar.spec

$ unrar

UNRAR 3.92 freeware      Copyright (c) 1993-2010 Alexander Roshal

Usage:     unrar  - -  
               <@listfiles...> 


  e             Extract files to current directory
  l[t,b]        List archive [technical, bare]
  p             Print file to stdout
  t             Test archive files
  v[t,b]        Verbosely list archive [technical,bare]
  x             Extract files with full path


  -             Stop switches scanning
  ad            Append archive name to destination path
  ai            Ignore file attributes
  ap      Set path inside archive
  c-            Disable comments show
  cfg-          Disable read configuration
  cl            Convert names to lower case
  cu            Convert names to upper case
  dh            Open shared files
  ep            Exclude paths from names
  ep3           Expand paths to full including the drive letter
  f             Freshen files
  id[c,d,p,q]   Disable messages
  ierr          Send all messages to stderr
  inul          Disable all messages
  kb            Keep broken extracted files
  n       Include only specified file
  n@            Read file names to include from stdin
  n@      Include files listed in specified list file
  o[+|-]        Set the overwrite mode
  or            Rename files automatically
  ow            Save or restore file owner and group
  p[password]   Set password
  p-            Do not query password
  r             Recurse subdirectories
  sl      Process files with size less than specified
  sm      Process files with size more than specified
  ta      Process files modified after  in YYYYMMDDHHMMSS format
  tb      Process files modified before  in YYYYMMDDHHMMSS format
  tn      Process files newer than 
  to      Process files older than 
  ts[N]  Save or restore file time (modification, creation, access)
  u             Update files
  v             List all volumes
  ver[n]        File version control
  vp            Pause before each volume
  x       Exclude specified file
  x@            Read file names to exclude from stdin
  x@      Exclude files listed in specified list file
  y             Assume Yes on all queries

Works well.

Firefox sync - sinking ?

Today I tried to use Firefox Sync.
I do not remember if I had a user account, but I tried to make a password reset.
I do not know if the same thing happens on Windows, but on Fedora, I received a strange thing output.
I assumed that it is a cookie, but it is not normal.
Maybe someone can tell what it is ...
Here's the picture with this strange number:

The myth of drop_caches

I will try to clarify the myth about drop_caches.
This along with other settings can be made in the folder: /proc/sys/vm/
First, the files in this directory can be used to tune the operation
of the virtual memory (VM) subsystem of the Linux kernel and also to
write out of dirty data to disk.
About drop_caches we can say that is only one of the options and not only make
causes the kernel to drop clean caches, and entries inodes from memory,
the result causing that memory to become free.
We have three basic options :

• to free pagecache: echo 1 > /proc/sys/vm/drop_caches
• to free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches
• to free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches

Note that user should run sync first.
What happens then?
The answer is also simple and clear.
If you drop the cache than the CPU load goes up. This happens because the cache is gone.
Also, available RAM goes up because the cache is empty.
Logical, the performance will suffer because you are not taking advantage of the cache.
Then over time, the caches will fill and this is a good thing if you don't instruct Linux to drop the caches.

In reality, dropping caches has a little positive effect on performance, but in fact, it tends to have a negative effect in long-term.
I hope I have correctly understood and explained, so if you think it is not, I wait for your feedback.

Fighting Blender, NVIDIA and GNOME ...

Today I spent some time with Blender, NVIDIA and GNOME ...
Since I did pre-update and put Fedora 15, the system worked well until today.
Today I tried to relax a bit with Blender 3D, but ...

[free-tutorials@user ~]$blender
Info: Config directory with "startup.blend" file not found.
Segmentation fault (core dumped)

How to prevent uploading that file? Simply using:

[free-tutorials@user ~]$blender --factory-startup 
Segmentation fault (core dumped)

Obviously, I should try to debug:

[free-tutorials@user ~]$blender --factory-startup  -d
Blender 2.57 (sub 0)
Build: 2011-04-27 16:56:56 Linux:32bit Release
argv[0] = blender
argv[1] = --factory-startup
argv[2] = -d
read file 
  Version 256 sub 6 svn r36063

ordered
 OBCube
 OBLamp
 OBCamera
Segmentation fault (core dumped)

Simply don't want, it's something related to graphics card ...

[free-tutorials@user ~]$blender --factory-startup  -d -noglsl 
Blender 2.57 (sub 0)
Build: 2011-04-27 16:56:56 Linux:32bit Release
argv[0] = blender
argv[1] = --factory-startup
argv[2] = -d
argv[3] = -noglsl
read file 
  Version 256 sub 6 svn r36063

ordered
 OBCube
 OBLamp
 OBCamera
Segmentation fault (core dumped)

So the problem is not related to GLSL.
Then I tried to see what glxinfo says.

[free-tutorials@user ~]$glxinfo | grep Error
Error: glXCreateContext failed

I found this problem and I added to xorg.conf the following lines of code.

Section "Files"
ModulePath "/usr/lib/xorg/modules/extensions/nvidia"
ModulePath "/usr/lib/xorg/modules/drivers"
ModulePath "/usr/lib/xorg/modules"
EndSection 

I must admit that after restarting the computer, greeted me with the gnome interface and unprecedented special effects.
Then I waited ... and waited ... I fixed up with a simple line of code:

$  gsettings set org.gnome.desktop.session session-name 'gnome-fallback'

... written in Xfce terminal, because in gnome I have not succeeded.
Now I have the old gnome, slightly improved but it works flawlessly with Blender 3D...

News: "A tour of Eclipse Helios" by IBM

It's a pretty good and complete information about Helios ...
Article begins:

Helios is the simultaneous release of 39 Eclipse projects. In terms of statistics, the Helios release includes 33 million lines of code developed by about 500 Eclipse.org committers from 44 companies...

You can read here and you will be impressed by the new Helios.
The best part for Linux users is Linux tools.
As Andrew Overholt says in the same article:

"The Linux Tools project also aims to increase the amount of Eclipse technology available in Linux distributions. We are working towards this goal by providing a build harness of the Eclipse SDK that is easy to consume for Linux distributions and already have a number of distribution consumers."

I have not yet found the negative aspects from the Helios ...

What things should be fixed quickly ?

Here are some things that should be repaired.
There are minor things or less, but make life a misery. There are things that generate more questions and more errors on the Internet.
This is an epidemic of questions there just because they are not repaired.

1. Google must give the possibility to download video files updated...
2. Python modules gdata do not work for all versions... ( and many modules has the same problem)
3. Python module ftplib does not know about SFTP, just FTP
4. Too many compilers for C and C + + and lack of advanced tutorials for setting them, especially gcc on windows
5. Social networks Spam filling our mail.


I will try to update the list over time.
I'm sure there are more ...

The word "includ" generates error in gmail.

I accidentally discovered an error.
I sent feedback to Google, I hope to resolve quickly.
The problem is with the word "include" is a word used in the Romanian language and means "include".
Because of this, I can not send emails it contains, Gmail asking to "include file"

The discovery of an ancient ancestors linux ...

Who says penguins are weak?
Linux is a good system if it is used by smart people.
Since ancient times people are born with penguins.
It seems that dinosaurs could not survive, but the Penguins have managed well.
They became smaller but everyone loves them.
Whether they are small and fast as Gentoo, or slower ... we are glad that we have no windows open.
More info here.