Yahoo! Inc. did something to its messenger servers, something that practically blocked all the Linux IM clients, such as Pidgin, Kopete, Empathy or GyachI.Yahoo! changed the login method! However, at this moment none of the aforementioned Instant Messenger clients for Linux can connect with the Yahoo protocol.

i searched for the solution of this problem and finally found it , then let’s fix this problem !

the solution was in the latest version of pidgin 2.5.7

1) download this key and save it in your Desktop

2) go to [System >> Administration >> Software Sources], enter your password and press [Third Party Software] tab

3) then add this line according your ubuntu distribution

Ubuntu 9.04

deb http://ppa.launchpad.net/pidgin-developers/ppa/ubuntu jaunty main

Ubuntu 8.10

deb http://ppa.launchpad.net/pidgin-developers/ppa/ubuntu intrepid main

4) go to [Authentication] tab and press [Import Key File] button and choose the key file in your Desktop

5) close window and preess [Reload]

6) and then [ System >> Administration >> Update Manager]

Enjoy your time

Source

Runlevels define what services or processes should be running on the system.

in other words : A runlevel is a software configuration of the system that allows only a selected group of processes to exist, Init can run the system in one of 6 runlevels.

so, what's the init?

Init is the parent of all processes on the system, it is executed by the kernel and is responsible for starting all other processes, it is the parent of all processes whose natural parents have died and it is responsible for reaping those when they die.

The init process reads the file “/etc/inittab” and uses this file to determine how to create processes. Also, note that init is always running and can dynamically do things and run processes based upon various signals. The administrator can also cause it to dynamically change system processes and runlevels by using the init program or editing the “/etc/inittab” file.

right, we informed that can run the system in one of 6 runlevels.These runlevels are 0-6. The system runs in only one of these runlevels at a time. Typically these runlevels are used for different purposes. Runlevels 0, 1, and 6 are reserved. For Redhat Linux . the runlevels are:

Let’s go to the Implementation part

the command

#init <RunLevel>

will change our current run level to the run level we put where <RunLevel> one of the values in the table above

if i need to know what’s the current run level running just type

#runlevel
    N 5

the previous example show that the system runlevel is “5″

if we need to change the default runlevel .so, just vim the file /etc/inittab

this file will opened.

# Terminal gettys (tty[1-6]) are handled by /etc/event.d/tty[1-6] and
# /etc/event.d/serial
#
# For information on how to write upstart event handlers, or how
# upstart works, see init(8), initctl(8), and events(5).
#
# Default runlevel. The runlevels used are:
#   0 - halt (Do NOT set initdefault to this)
#   1 - Single user mode
#   2 - Multiuser, without NFS (The same as 3, if you do not have networking)
#   3 - Full multiuser mode
#   4 - unused
#   5 - X11
#   6 - reboot (Do NOT set initdefault to this)
#
id:5:initdefault:

we see at the last line id:5:initdefault: just change the value 5 to your prefer runlevel and save.

There will be a time when you want to know what services are running, and the different runlevels they are specified in. You can use a simple command to display a list of all runlevels and services used by them.
just type

#chkconfig --list

the out put will be like this

NetworkManager  0:off   1:off   2:on    3:on    4:on    5:on    6:off
anacron                 0:off   1:off   2:on    3:off   4:on    5:on    6:off
atd                     0:off   1:off   2:off   3:on    4:on    5:on    6:off
auditd                  0:off   1:off   2:on    3:on    4:on    5:on    6:off
avahi-daemon      0:off   1:off   2:off   3:on    4:on    5:on    6:off
bluetooth             0:off   1:off   2:off   3:on    4:on    5:on    6:off
cpuspeed             0:off   1:on    2:on    3:on    4:on    5:on    6:off
crond                   0:off   1:off   2:on    3:on    4:on    5:on    6:off
cups                     0:off   1:off   2:on    3:on    4:on    5:on    6:off
dnsmasq               0:off   1:off   2:off   3:off   4:off   5:off   6:off
firstboot               0:off   1:off   2:off   3:off   4:off   5:off   6:off
gpm                     0:off   1:off   2:on    3:on    4:on    5:on    6:off
haldaemon           0:off   1:off   2:off   3:on    4:on    5:on    6:off
httpd                   0:off   1:off   2:off   3:off   4:off   5:off   6:off
ip6tables             0:off   1:off   2:on    3:on    4:on    5:on    6:off

the first column: determine the service name
the other six colums:determines the service status in all runlevels (on | off)

let’s use this output for other useful command

NetworkManager  0:off   1:off   2:on    3:on    4:on    5:on    6:off

we see that the networkmanager service is off in runlevels (0,1 and 6) and on in the others
so we want to close the service in runlevel(3)

just type this command

#chkconfig --level 3 NetworkManager off

if we want to re open just change off to on

This time let’s talk about something that every single Linux user – from the typical user to the system admin – almost use it everyday !!

Wow !! That’s cool. But, What is it?

Yeah as the title tels you, “Linux Documentation”.

So, What is the Linux Documentation? why we use it rapidly? and how to use it? that is what this post about.
We will not cover all Documentation tools in this post, but it will be followed by other posts to describe the next tools isA.

1)Man Pages.

First of all, let’s go back in time. To the early days of Unix. There was so many developers who are developing new applications for the Unix and even develop in the Unix itself ! Yes, Unix was a free software in it’s early days.

So, people wanted to create a standard that all developers use to make documentation for there programs and for the developers of the Operating System itself to make documentation for the every single piece of the Operating System. That’s when they invented Man Pages (Manual Pages).

Yes, Man Pages are there from the early days of Unix. And Linux keeps using it Because it became a standard for documentation in all Unix Like Operating Systems.
Now let’s start our tour in Linux Documentation by the Man Pages.

• Man pages files are stored under

/usr/share/man/*

• To view the man page for any Command (program) just invoke

#man [command]

like

#man ls

• That is how the man page looks like.

• Navigation through the page is simple

• ↑↓←→  to scroll (up – down – left – right) through the page.
• (Page up, Page down, Home, End) to scroll one page (up – down), go to the (top – end) of the man page.
• Press “q” to quit the man page.
• Press “h” for complete help about man pages.

• You also can use the Man page self documentation page

#man man

Now, let’s dive in deeper in Man Pages.
Man Pages doesn’t only document user commands, It’s documenting Everything !!

Yes, it does. So, Man Pages categorizes the Documentation into eight different categories to ease the use of the documentation. and these Categories are :-

1. User Commands
2. System Calls
3. Subroutines (C library functions)
4. Special Files
5. File Formats and Protocols
6. Games
7. Macros and Conventions (Miscellaneous)
8. System Administration Commands and daemons
9. Kernel  routines

There some more categories like

• (0) C library header files
• (p) POSIX specifications
• (x) X Window System documentation
• (n) Tcl/Tk keywords

To search on a specific category use

#man [category number] [command]

like

#man 1 passwd          —–> view the man page about the (passwd) command.

#man 5 passwd          —–> view the man page about the (/etc/passwd) configuration file.

To view all man pages about a keyword

man -a [keyword]

like

man -a passwd

That will show the first matching man page, then after you press “q” to quit, it will show you the next matching page …..etc.

Now I will leave you get familiar with Man Pages. and in the next post – isA – we will talk about the next documentation tool in Linux.
Bye.

so you can’t install it directly

even when you go to nvidia site and try to install it to your linux, you’ll be disappointed because compiz and other 3d effects won’t work perfectly

so you’ll have to install the “akmod-nvidia” package

first, know what’s your kernel version by typing:

#uname -r

then install nvidia

for redhat based:

#yum install akmod-nvidia-#kernel number

in ubuntu:

apt-get install akmod-nvidia-#kernel number

note that the bold words are comments

you can try using:

yum install akmod-nvidia-$(uname -r)

instead of the two lines above (but i didn’t test this one)

regards …

Problem

you might install the flash plugin to enjoy watching youtube or whatever

but unfortunately, the sound is not working!!

Solution

it’s too simple

just install “libflashsupport” package

<blockquote>yum install libflashsupport*</blockquote>

make sure you’re including the “*” in the yum line

i faced an error while installing Virtualbox on my fedora machine, and i could not create any virtual machines!!

but i found that there were some steps required to complete the installation

so i had to install some packages and do the steps

Solution

after downloading and installing virtualbox, you’ll have to write these commands:

yum install make automake autoconf gcc kernel-devel

/etc/init.d/vboxdrv setup

usermod -G vboxusers -a username

Enjoy running your Vbox

but at the same time you can copy files into the same X directory using the “root” user

so how do i get the permission for writing in X using any user … not root only!!

well …

have you ever wrote “ls -l” command???

if you’ve done so, have you noticed the first column of the output?!

it may look like this:

-rwxrwxrwx

1) the first (-) represent the file type, so if it’s like that (-) you’ll know that this is a file

and if it is (d), it’s a Directory

and (l) stands for Link

there are more letters but these are the most important ones

2) then the next 9 letters represent 3 partitions, they are: OWNER (u), GROUP (g), OTHER (o) respectively

each of them consists of 3 letters: rwx

r=read (access to read files)

w=write (access to write into files)

x=execute (access to run files)

let me give a simple example for using permissions:

suppose that “boody“, “3abed“, “didooofidooo” are members in a group named “group1“

and “Hunikal” & “noor” are in “group2“

“boody” created a file, then he found that the permission is -rw-rw-r–

ok what does this actually mean?!

1) this means that this is a normal file (this is why (-) is there)

2) and the owner of the file (boody) can read the file and also write into it

3) and the owner’s group (group1) can also read and write into the file, this means that “3abed” and “didooofidooo” can also read-write into this file, as they’re in the same group (group1)

3)then we’ll find that “Hunikal” and “noor” can only read the file but not write into it, as they are not the “OWNER” or in the “owner’s GROUP”, so they are from “OTHERS”

Changing Permissions

there are two ways for changing permissions

both can be done using “chmod” command

1)Char Method

if you want to change the permission of a file named “Perm” from -rwxr-xr-x to -rw-rw-r-x

we can see that we only have to change the owner’s permission (u) from rwx to rw- so we’ll use the following command

#chmod u-x Perm

then change the group’s permission (g) from r-x to rw- so we’ll use the follwing command

#chmod g-w+x Perm

actually we could change this in only one command

#chmod u-x,g-w+x Perm

2)Numeric Method

we have three primary numbers:

4, 2 and 1

4 adds r permission (read permission)

2 adds w permission (write permission)

1 adds x permission (execute permission)

so you can change a file’s permission from -rwxr-xr-x to -rw-rw-r-x using the following command

#chmod 665 file_name

6=4+2=rw-

5=4+1=r-x

so we can give a -rwxrwxrwx permission using the following command

#chmod 777 file_name

umask

from wikipedia:

umask (abbreviated from user mask) is a command and a function in POSIX environments which set the default permission modes for newly created files and directories of the current process

you can know your umask using “umask” command:

#umask

the most important thing you need to know about umask is that:

permission = 777 – umask

so if your umask equals 0022, your files’ permissions will be 777-022=755

and this means when you create a file you’ll find the file’s permission is -rwxr-xr-x (755)

changing umask

you can change the umask (for example: to 023) using “umask” command:

#umask 023

but when you restart your computer, you’ll find that the umask returned to it’s old value

so we have to edit /etc/bashrc file

#vi /etc/bashrc

and change the umask value then save the file

————————————————————-

that’s all

thanQ

bye

the problem is that the system clock is some hours forward or backward, and that’s because Ubuntu by default considers that your system clock is adjusted to the UTC time.
So if your system clock is adjusted to your local time, here the problems will start.

Now you should configure your system to consider that you system clock is adjusted to your local time. So, you should do that:-

Open this file with your favorite text editor:

/etc/default/rcS

Find this line:

UTC=yes

replace it with:

UTC=no

Now restart your machine and you will find that your system time is correct.

problem

first time i installed fedora(9) on my Dell laptop, i found that i couldn’t use the mouse touchpad as a left click

and that didn’t bother me, because it was useful somehow

but when i tried to install ubuntu, i found that the toutchpad click is working very well

that doesn’t mean that the solution is to install ubuntu!!!

you must think and search for your problems’ solutions and never give up till you find them!!

Solution

few days later, i found the solution on cat-h4ck3rz forum and i wanted to share it

#vi /etc/X11/xorg.conf

add the following line in the ServerLayout Section

InputDevice "TouchPad" "CorePointer"

then add this new section:

Section "InputDevice"
Driver "synaptics"
Identifier "TouchPad"
Option "SendCoreEvents"
Option "Protocol" "auto-dev"
Option "SHMConfig" "on"
Option "TapButton1" "1"
Option "TapButton2" "2"
EndSection

that’s it!

now restart your X window using (alt+ctrl+backspace)

and you’ll find your touchpad click is working!

good luck

So, what happen’s?

• First you will find that the border around all windows is gone!! it disappears!!.
• then if you open a terminal you will see that the text is not visible in it!!!
• some times you find that Minimization an Maximization is not working.

Do you know why does it all hapen?

that’s because compiz which is your window manager is crashed!! and unfortunately, the window manager is the application that is responsible for making a border around your windows to enable you to resize or drag the window.
It’s also responsible for the minimization and maximization for windows, desktop effects, etc

Now I think you see how annoying it is when it craches!!

So, what is the solution?

some times.. just pressing Alt+F2 then writing this command solves the problem:

compiz –replace

but sometimes it dosen’t solve the problem and when you run this command in a terminal you get an error output like that:

Checking for Xgl: not present.
Detected PCI ID for VGA: 01:00.0 0300: 10de:0185 (rev c1) (prog-if 00 [VGA controller])
Checking for texture_from_pixmap: present.
Checking for non power of two support: present.
Checking for Composite extension: present.
Comparing resolution (1024×768) to maximum 3D texture size (2048): Passed.
Checking for nVidia: present.
Checking for FBConfig: present.
Checking for Xgl: not present.
Attempted to unregister path (path[0] = org path[1] = freedesktop) which isn’t registered
Attempted to unregister path (path[0] = org path[1] = freedesktop) which isn’t registered
Attempted to unregister path (path[0] = org path[1] = freedesktop) which isn’t registered

Or sometimes like that

Checking for Xgl: not present.
No whitelisted driver found
aborting and using fallback: /usr/bin/metacity

this Error happens with Nvidia graphic cards and the soulution is so simple:

first: check if you have the nvidia-glx driver installed in your system.

second: if it’s installed but you still have the same problem then you should edit this file by hand:

/etc/X11/xorg.conf

and in the “Screen” section add this line:

Option “AddARGBGLXVisuals” “True”

now restart your X server by pressing Alt+Ctrl+BackSpace and you should find that the problem is solved.

if it’s not add this line also to the same file in the same section (But I Really Don’t Recommend That, Do it only if you have to)

Option “DisableGLXRootClipping” “True”

I hope this helps anybody.