Techie Notes

List Tar file contents on AIX

2011-03-30T19:43:00.001+02:00

tar -tvf filename.tar

Get Time from Oracle DB in SQLPlus

2011-03-25T15:40:00.002+02:00

select systimestamp from dual;

Blog Moved to Wordpress

2010-06-03T12:43:00.002+03:00

Blog moved to http://techienotes.info which redirects to http://mytechnicalthoughts.wordpress.com

New Primary HDD: A full Ubuntu backup & restoration experience (Draft)

2010-05-26T16:37:00.025+03:00

Steps:

Use "SystemRescueCD"
"fsarchiver savefs"
"fsarchiver restfs"
mount /dev/sda1 /mnt
mount /dev/sda2 /mnt/boot #skip this if don't have a separate /boot partition
grub2-install --root-directory=/mnt/ /dev/sda

Operation Stats:

Original Disk Space used on the HDD to backup: 45 GB
Size of the backup images using "fsarchiver" default settings: 30 GB
Time taken to restore the whole HDD: around 45 min.
Bootloader restoration (grub2): 1 min.

Impression: Very fast, very little disk space used, very happy :)

Install Bluecurve theme on Ubuntu box

2010-05-18T03:55:00.001+03:00

Here's the way to install Redhat's most famous theme "Bluecurve":
It worked me on Ubuntu 10.04

http://ubuntuforums.org/showthread.php?t=342060

convert files from one encoding to another using iconv

2010-05-17T04:26:00.003+03:00

I have subtitles that was written on M$ windows that were saved using WINDOWS-1256 encoding and were not working on my Linux box.

I found this command to convert from one encoding to another:

iconv -f WINDOWS-1256 <Ice_age_3.sub> Ice_age_3_utf8.sub

Display CPU Temperature Graphically using a Panel Applet in Ubuntu

2010-05-13T23:57:00.001+03:00

"sudo apt-get install sensors-applet"

Right-click on any panel and add the new applet, then easily configure it to display the temperature, fan speed, HDD temperature ...etc

know the return value of a native (c) program in linux

2010-05-13T04:15:00.000+03:00

Hi folks
use this command:
echo $?
to know the return value of a native program in Linux.
try it yourself:

scenario 1:

more 
echo $?  #(watch the result, it will be 1, which means unsuccess)

scenario 2:

echo "hello world" > file
more file
echo $?  #(watch the result, it will be 0, means success)

Create NTFS Partition with gparted in Ubuntu

2010-05-12T17:18:00.000+03:00

The "ntfs" option is dimmed by default, to enable it you should install the necessary package: "sudo apt-get install ntfsprogs"

That's it, just re-open gparted and you're ready to go :)

Get CPU Temperature From Command Line in Ubuntu

2010-05-12T16:52:00.002+03:00

more /proc/acpi/thermal_zone/THM0/temperature
more /proc/acpi/thermal_zone/THM1/temperature

As I have two processors "THM0" and "THM1"

Source

Permanently Blacklist a Kernel Module in Ubuntu

2010-05-12T16:06:00.000+03:00

Edit "/etc/modprobe.d/blacklist.conf"
Add the module you want to remove, e.g. to blacklist the "kvm_intel" module, add this line "blacklist kvm_intel"

Disable a Laptop's Touchpad in Ubuntu Karmic (and later as I well I guess)

2010-05-06T12:33:00.000+03:00

Applications -> Ubuntu Software Center
Search for Touchpad
System -> Preferences -> Touchpad
Untick "Enable Touchpad"

How to uncompress zip file on AIX

2010-05-04T16:38:00.001+03:00

To uncompress a zip file on AIX, use "unzip" command:
unzip file_name.zip

Install Linux Distro. without burning on CDs

2010-04-30T05:25:00.001+03:00

While searching, I found this cool program that enables you to burn Linux Distro. on USB Devices
http://unetbootin.sourceforge.net/

Download Internet Files from the terminal in Ubuntu

2010-04-30T04:56:00.001+03:00

wget url

e.g. wget http://files.ubuntu-manual.org/manuals/getting-started-with-ubuntu/10.04/en_US/screen/Getting%20Started%20with%20Ubuntu%2010.04.pdf

Clear Totem (and other programs) History in Ubuntu

2010-04-30T04:02:00.000+03:00

Change core file path for IBM HTTP Server 2.0.47

2010-04-28T17:56:00.003+02:00

To change the default path where the core file is dumped for IBM HTTP Server 2.0.47 on AIX
1- Go to IBM HTTP server conf directory (ex: /usr/IBMIHS/conf)
2- Open httpd.conf
3- Edit the "CoreDumpDirectory" to the required directory (ex: CoreDumpDirectory "/usr/IBMIHS/corefiles")

Kill signal to dump core file

2010-04-28T17:51:00.001+02:00

To kill a process and make it dump a core file, use the "6" signal
kill -6 PID

How to enable full core on AIX

2010-04-28T17:36:00.003+02:00

1- To obtain full core files on AIX, set the following ulimit options:
ulimit -c unlimited turn on corefiles with unlimited size
ulimit -n unlimited allows an unlimited number of open file
descriptors
ulimit -d unlimited sets the user data limit to unlimited
ulimit -f unlimited sets the file limit to unlimited

You can display the current ulimit settings with:
ulimit -a

2- Set the following in smitty:
1. Start smitty as root
2. Go to System Environments -> Change/Show Characteristics of Operating System
3. Set the Enable full CORE dump option to TRUE

Alternatively, you can run chdev -l sys0 -a fullcore='true' as root.

You can check the setting with lsattr -D -c sys -a fullcore -H, which should produce output similar to this:
attribute deflt description user_settable
fullcore false Enable full CORE dump True

Reference: IBM Web Site, AIX Help

Accesing Linux partitions (ext2/ext3) from Windows

2010-04-26T06:57:00.004+02:00

If you need to gain read/write access for Linux partitions from windows box, http://www.fs-driver.org/ provides you with a simple program that enables you to gain read/write access to ext2/ext3 partitions.

Easiest way to install programs in OpenSUSE

2010-04-25T01:11:00.002+02:00

Go here : http://software.opensuse.org/search
in the search box write search key, and then on the list below, click "1-click install" button.

Add a job to crontab that runs every minute on AIX

2010-04-18T17:32:00.000+02:00

crontab -e
0-59 * * * * hobba

crontab -e: opens a text file (via vi) to add your job

0-59: is to run every minute

hobba: is the command to run, it's either a Unix command or a script

crontab logs on AIX 5.3

2010-04-18T17:23:00.002+02:00

/var/adm/cron/log

Setup Google Apps Custom Domain (e.g. @techienotes.info) on Empathy

2010-04-18T15:58:00.001+02:00

Create a new Jabber account and enter the following details:

account : username@techienotes.info
encryption required TLS/ssl : (unmarked)
ignore ssl certificate error : (unmarked)
server : talk.google.com
port : 5222 (default)
use old ssl : (unmarked)

Source

Bash Script to run a sql file (Draft) - Part 1

2010-04-17T19:14:00.004+02:00

#!/usr/bin/bash

# This script calls the Ad_1.sql script and spools the output with date stamp to a log file
# Update: You MUST add your environment variables one way or another, e.g. look below

export ORACLE_BASE=/oracle
export ORACLE_HOME=/oracle/OraHome_1
PATH=${PATH}:${ORACLE_HOME}/bin; export PATH
export LIBPATH=${LIBPATH}:${ORACLE_HOME}/lib32:${ORACLE_HOME}/lib

if [ ! -f lock ]; then

sqlplus -s user/password@sid << EOF
column dcol new_value mydate noprint
select sysdate dcol from dual;
spool log_ad_1_&mydate..log
@Ad_1.sql;
spool off
EOF

fi

where:

if [ ! -f lock ]: very useful statement, it checks whether a file named "lock" exists or not, if it doesn't exist, it will not execute the code block within.

sqlplus -s usr/passwod@sid: to run sqlplus commands as if I'm entering the commands manually, the -s flag lets sqlplus accept the standardin input until it finds the word "EOF"

Part 2 will be about adding the above script in crontab and executing it daily.

Putting the Current Date in a Spool File Name in sqlplus

2010-04-14T15:58:00.000+02:00

Using SYSDATE you can query the current date and put it in a substitution variable. The substitution variable can then be used in a SPOOL command:

column dcol new_value mydate noprint
select to_char(sysdate,'YYYYMMDD') dcol from dual;
spool &mydate.report.txt

-- my report goes here
select last_name from employees;
spool off

Some useful Google Chrome extensions that I use - Part 3

2010-04-11T15:45:00.001+02:00

Well, this is the article number 200 in this blog, I'm so proud of this :)

Copy Without Formatting: Enables you to copy text from any website without its formatting, very useful in some situations where you just need to extract the text without its specific font, color ...etc, I found it very useful in blogging, there is a similar addon for firefox that does the same exactly.

Unlock Oracle user and set FAILED_LOGIN_ATTEMPTS to unlimited

2010-04-11T15:05:00.005+02:00

View Profile Assigned to a User:

SELECT PROFILE FROM DBA_USERS
WHERE USERNAME='SCOTT';

PROFILE
----------
DEFAULT

View Limits Set for the Profile:

SELECT RESOURCE_NAME, LIMIT FROM DBA_PROFILES
WHERE PROFILE='DEFAULT';

RESOURCE_NAME LIMIT
------------------------ -------------
COMPOSITE_LIMIT UNLIMITED
SESSIONS_PER_USER UNLIMITED
CPU_PER_SESSION UNLIMITED
CPU_PER_CALL UNLIMITED
LOGICAL_READS_PER_SESSION UNLIMITED
LOGICAL_READS_PER_CALL UNLIMITED
IDLE_TIME UNLIMITED
CONNECT_TIME UNLIMITED
PRIVATE_SGA UNLIMITED
FAILED_LOGIN_ATTEMPTS 10
PASSWORD_LIFE_TIME UNLIMITED
PASSWORD_REUSE_TIME UNLIMITED
PASSWORD_REUSE_MAX UNLIMITED
PASSWORD_VERIFY_ FUNCTION NULL
PASSWORD_LOCK_TIME UNLIMITED
PASSWORD_GRACE_TIME UNLIMITED
16 rows selected.

Alter FAILED_LOGIN_ATTEMPTS Parameter:

From the user's profile we can see that the FAILED_LOGIN_ATTEMPTS parameter is set to a value of 10. Now we run below command to make it UNLIMITED.

SQL> ALTER PROFILE DEFAULT LIMIT FAILED_LOGIN_ATTEMPTS UNLIMITED;
Profile altered.

Unlock the Account:

Finally we will unlock the account by running below command.

SQL> ALTER USER SCOTT ACCOUNT UNLOCK;

Update: You'd better NOT change the settings for the "DEFAULT" profile, create a new profile instead "create profile new_profile LIMIT bla bla bla"and then assign it to the given user "alter user olap profile new_profile"

Source

Some useful Google Chrome extensions that I use - Part 2

2010-04-11T12:40:00.000+02:00

SmoothScroll: As the name indicates, it allows smooth scrolling of the web page, makes chrome more elegant :)
MiddleButtonScroll: A feature that I really wanted and couldn't find at first on Chrome is the ability to click the middle mouse button and smoothly scroll upwards or downwards by just moving the mouse, this extension does exactly this!
Stop Autoplay for YouTube: As the name indicates, whenever you open a youtube video, especially when opening many videos simultaneously in multiple tabs, it stops the video from auto-playing and guess what, it pre-buffers as well :), i.e. it starts loading the video as if you clicked the pause button.
Webpage Screenshot: As the name indicates, it allows you to take screenshots of the webpages you browse, it can also add large pages - that require scrolling - in one screenshot.

Some useful Google Chrome extensions that I use - Part 1

2010-04-11T12:24:00.001+02:00

AdThwart: Blocks ads based on Firefox Adblock plus filter engine. I prefer this one to the others as it works exactly the same as Adblock plus on Firefox, and other seem buggy, up till now.
Google Mail Checker Plus: Checks your Gmail, adds a little icon to the upper right corner of the browser and provides nice visual and sound effects to indicate any new incoming mails
PanicButton: Don't get caught :)), a single click or a keyboard shortcut can hide all your tabs and can even password-protect them not to allow anyone to recover the ones you've hidden

$@ is not "$@"

2010-04-07T17:25:00.004+02:00

when you want to pass multiple parameters through you shell script, you use $@
ex:

#! /bin/sh
echo $@

and then execute this file:

./script1 hello world

the script will prints "Hello world"

But be ware, $@ is not "$@" !!

The story is, I wrote some Java file that accepts 1 argument from the command line, such like this:

public class SayHello{
    public static void main(String[] args){
        if (args.length != 1){
            System.out.println("Usage: SayHello ");
            System.exit(-1);
        }
    // do other staff here
    }
}

I have wrapped this program in a shell file "sayHello.sh":

#! /bin/sh
java SayHello $@

But the result was unexpected, as when I run with this command:

./sayHello.sh "Mohammed Hewedy"

I got

Usage: SayHello

I found the problem in the shell file, that I should use "$@" instead of $@
So, the script should be:

#! /bin/sh
java SayHello "$@"

Restarting USB Storage Modules in Ubuntu

2010-03-30T18:07:00.002+02:00

"sudo modprobe -r usb_storage"
"sudo modprobe usb_storage"

It's only because I had a problem in mounting any USB storage, it happened with me once
and I had to restart my machine, and I hate having to do so :)

Source

Download Videos From YouTube using Ubuntu

2010-03-28T20:32:00.000+02:00

A very nice command-line tool that allows you to download videos from Youtube:

"sudo apt-get install youtube-dl"

After the installation process, run:

"youtube-dl video_url"

Stop YouTube from autoplaying a video when opened

2010-03-28T20:26:00.000+02:00

A very nice plugin for Google Chrome (or Chromium) that allows you to open as much videos as you want without them playing automatically where you must open each video and pause it yourself.

The surprise is: It's pre-buffering :)

Stop Autoplay for YouTube

Setup an SSH/SFTP Server on Ubuntu

2010-03-28T16:51:00.000+02:00

"sudo apt-get install openssh-server"

That's it, you can now connect to your machine via SSH/SFTP from any other machine on the same network, it's easy, fast and secure.

Setup an FTP server on Ubuntu

2010-03-28T15:39:00.004+02:00

Installing an FTP server on your machine facilitates sharing and transferring files easily and quickly.

ProFTPD is an FTP server that is easy to install, use, and configure.

To install ProFTPD on ubuntu:
sudo apt-get install proftpd

To start proftpd;
sudo /etc/init.d/proftpd start

To configure proftpd, edit the file:
/etc/proftpd/proftpd.conf

Adding a software repository from Ubuntu PPA in Ubuntu Karmic and later

2010-03-25T19:14:00.001+02:00

This new method is easier than the old one which required you to edit your software sources manually, and then get the key and import it. The new one is as follows:

Go to the PPA page of your interest, e.g. URL, check the name of the new repository, it is "ppa:transmissionbt/ppa" in my example.
Open a terminal and type "sudo add-apt-repository ppa:transmissionbt/ppa"
Done! This both adds the entry to your software sources list as well as importing the key which authenticates that repository.
Don't forget to refresh your repository to be able to update/install new packages "sudo apt-get update"

PPA = Personal Package Archives, i.e. the user-contributed software repositories.

Workaround for Ubuntu Karmic Bug: Window List buttons do not always respond to mouse clicks

2010-03-25T17:20:00.002+02:00

Here is the bug URL

I got the solution from there as well, as this was an extremely annoying bug for me and I consider it a FATAL One!

Open a terminal and run the following command:

"nohup env GDK_NATIVE_WINDOWS=1 gnome-panel --replace &"

Where:

"nohup": To run the command independent from the terminal, so as not to cancel the action if the terminal is closed.

'&': Must be put at the end of a command run using "nohup" to run it in the background and avoid canceling the command.

That's it!

The above command will restart the "gnome-panel" and you'll find that the bug disappeared.

I haven't restarted my machine yet to know whether this command is persistent or not (I think not), but anyway it can be easily put in the session startup if it's not.

Thanks go to "schuetza" who suggested this nice workaround on the original bug report.

Extract audio from a video file in Ubuntu

2010-03-22T17:18:00.001+02:00

"mplayer -dumpaudio GummyBearSong.avi -dumpfile gummybear.mp3"

Where:

"GummyBearSong.avi" is the source video, in the example above it was 30 MB
"gummybear.mp3" is the output audio file (in mp3 format), was about 3 MB in size

and surprisingly it took 1 second only!!

I think it runs on other video formats as well, as the source article was working on an "flv" file.

Enforce any application to appear full screen in gnome

2010-03-19T02:21:00.002+02:00

In Gnome, you can force any application to go full screen;
Open System=>Preferences=>Keyboard shortcuts
Under "Window Management" assigne any key combinations such as "CTL+SHIFT+F" for "Toggle Fullscreen mode".
Open any application (firefox, eclipse, ....) and press "CTRL + SHIFT + F", the program will goes in full screen mode.

pass entire parameters in shell scripts

2010-03-18T17:27:00.002+02:00

example bash file:

save the following in a file called print.sh
#!/bin/bash
echo "$@"
and then :
chmod +x print.sh
./print.sh hello world
Note that, all the parameters you pass to print.sh will be passed to echo, this because of "$@"

List sessions for a user using Siebel CLI

2010-03-16T18:16:00.002+02:00

"list sessions for login user_name"

LAN Chat Server & Client in Ubuntu

2010-03-16T00:15:00.002+02:00

"sudo apt-get install chatplus chatplus-server"

Extract a certain file to a certain directory from a tar archive using GNU Tar

2010-03-15T19:44:00.002+02:00

"gtar -C hobba -xvf aamr.tar aamr/1"

where:

"hobba" is the directory to extract to
"aamr.tar" is the archive from which we'll extract the file
"aamr/1" is the file inside the archive to be extracted to the destination directory (hobba).

A more convenient alternative to AIX tar; gtar

2010-03-15T19:33:00.000+02:00

Searched everywhere just to know how to use the "tar" command to extract an archive to a certain folder instead of extracting it using the same directory structure inside, and so here are the steps:

Don't use the "tar" program
Download the GNU tar rpm from the AIX toolbox
Install it "rpm -ivh blablabla.rpm", you must have installed rpm at first from there of course, note that you must have root access to install that package
logout and then back in, use "gtar" from now on.

How to unset an environment variable in Bash

2010-03-15T13:34:00.002+02:00

"unset variable_name"

How to start tasks for a component in Siebel's CLI

2010-03-14T22:52:00.000+02:00

Although I still feel real grief in my heart, but here is my first blog entry after Kooka's - my beloved Guinea Pig - death:

"start task for component component_name server server_name"

How to restart the VirtualBox kernel module in Ubuntu

2010-03-14T12:30:00.000+02:00

If you're encountering problems in Virtualbox on Ubuntu and you feel you need to restart your machine, don't! You're on Linux, not windows! You can just close Virtualbox and then restart the Virtualbox kernel module by running the following:

"/etc/init.d/vboxdrv restart"

And then start Virtualbox and try again :)

Copy text without formatting (as plain text) in Firefox

2010-03-12T19:43:00.000+02:00

Ever wanted to copy and paste text from a website without the need for its formatting, e.g. copying some colored text with large font from a website and pasting it inside your gmail account? If so, then this add-on is for you: https://addons.mozilla.org/en-US/firefox/addon/134

After installing and restarting your firefox, right-click on any selected text and choose "Copy as plain text" and then paste it anywhere.

How to install Guest Additions for Ubuntu Guest in Virtualbox

2010-03-11T14:28:00.003+02:00

Guest Additions are very useful in VirtualBox (or any other virtualization software in general), it installs virtual adapters for your hardware and enables the following:

Better graphics support (very useful when resizing the desktop or changing the guest's resolution)
Folder sharing between the host and the guest (you can refer to this article for a how-to)
Mouse Integration

Maybe other features as well which I don't know. To install the guest addtions, you can simply follow the following five steps:

Click Devices->Install Guest Additions, this will mount a virtual cdrom containing the files from which we will install the guest addtions.
Open a terminal and navigate to the folder containing the guest additions "cd /media/cdrom"
Run the guest addition installer "sudo sh VBoxLinuxAdditions-x86.run"
Wait till the additions are installed and the kernel modules are compiled, note that this may take a few minutes.
Restart the Ubuntu guest.

This article is dedicated to my cousin Midoooz, to use it in his first virtual machine :)

Install Google Gears on Firefox on Ubuntu Karmic

2010-03-09T15:14:00.001+02:00

So simple:

Don't install from the website, it will - till the time of this article - give you an error message that your browser isn't supported
Install the "gears" package, e.g. open a terminal and type "sudo apt-get install gears"
Restart your browser
QED :)

Bash Switch statement

2010-03-08T17:06:00.004+02:00

If you have some server that need some script that control it (such as scripts found in /etc/init.d), here's that script:

open a text file and put the following in :

#! /bin/sh
case "$1" in
start)
  echo "START";
  ## command to start your server
  ;;
stop)
  echo "STOP";
  ## command to stop your server
  ;;
*)
 echo "Usage : $0 {start|stop}"
 exit -1;
esac

Then of course

chomd +x <file_name>

And you're done.

The Log Event responsible for logging user actions in Siebel

2010-03-08T12:50:00.000+02:00

To add which user and what he/she was doing exactly to the log files, raise the log level for the event "EventContext", e.g. "change evtloglvl EventContext=log_level for comp component_name", remove the "comp" keyword if you want it for all components.

Increase the log level for some events (based on a wildcard search) for a specific component using the Siebel CLI

2010-03-08T12:37:00.001+02:00

Firstly, list them: "list evtloglvl %keyword% for comp component_name"
Finally, change the log level "change evtloglvl %keyword%=log_level for comp component_name"

How to edit the Grub2 bootloader entries (used for some new linux distros, e.g. Ubuntu Karmic)

2010-03-07T15:07:00.001+02:00

I used to edit the "/boot/grub/menu.lst", that's not the case in grub2:

Firstly, you should edit the "/etc/default/grub"
Next, run the "update-grub" command, that's it :)

How to change the default CPU governer (CPU Frequency) in Ubuntu Karmic (might work for other versions as well)

2010-03-05T23:43:00.000+02:00

The problem is that no matter what, when I change the CPU governer using the "CPU Frequency Scaling" gnome applet in my Ubuntu Karmic, it always defaults to "ondemand", I searched in some forums and finally developed a nice and easy way:

Set the frequency you need via the CPU Frequency Scaling applet (per CPU core)
Rename or remove the "/etc/init.d/ondemand" file, I prefer you rename it, much safer I guess :), i.e. "sudo mv /etc/init.d/ondemand /etc/init.d/ondemand.bak"
Reboot and see it working yourself :)

How to change the gnome default keyring password in Ubuntu Karmic (may apply to other versions as well)

2010-03-05T13:33:00.000+02:00

After I initially set it, I needed to change it so that it matches my login password:

Open a terminal
type "seahorse"
Right-click on "Passwords: login" and click "change password"
Type your old password and then your new one.
Done!

enjoy :)

How to raise the log level for all events for a Siebel component from the Siebel CLI

2010-02-24T12:26:00.004+02:00

"change evtloglvl %= log_level for comp component_name"

Thanks go to Osama Magdy for the info :)

How to edit scheduled jobs (crontab) on AIX

2010-02-23T18:58:00.000+02:00

A very useful link: http://publib.boulder.ibm.com/infocenter/discover/v8r4/index.jsp?topic=/com.ibm.discovery.ds.publish.doc/c_UG_Configuring_Cron_Job.htm

How to change your current username on Ubuntu Linux

2010-02-04T18:22:00.001+02:00

Beware, this action is VERY dangerous and might ruin some of your running applications, I tried it first on a virtual machine and then my actual machine and it messed up 2 or 3 apps only, I was lucky as these were easy to fix, here we go (Read the instructions below carefully):

usermod -l newname -m -d /home/newname oldname

Please note that you MUST:

be logged out from the user that you will change the "username" for
and make sure all that user's applications are closed.

Thanks go to prshah for his post here

Bash script to monitor background processes

2010-02-02T18:47:00.000+02:00

while [ 1 ]; do ps -ef | grep bzip2; echo "============================================="; sleep 5; done;

where:

bzip2: is the process name or part of the process name

Press Ctrl+c at any time to cancel the process

How to compress a file into multiple splitted files (Like what you used to do in MS Windows using Winrar)

2010-02-01T21:21:00.000+02:00

I made it through the GUI this time, not using the command line:

Opened Gnome File Roller (Applications ->Accessories->Archive Manager)
Dragged the folder I wanted to compress inside it
Click "Create Archive"
Click "Other Options"
Tick "Split in volumes of" and choose the split size (how many MB you want each file split to be)
Choose "Archive Type" to be "7z". Note: I selected "Automatic" at first, but it didn't work! Do you know why??
Click "Create"
Enjoy :)

SQL statement to unlock user account in oracle

2010-01-31T18:17:00.003+02:00

ALTER USER username ACCOUNT UNLOCK;

How to split a text file in Ubuntu

2010-01-31T16:53:00.002+02:00

Simple! Just use the "split" command, if no arguments are specified, it will split the text file to files each containing 1,000 lines of text.

Import Your Gmail Contacts into Mozilla Thunderbird

2010-01-30T01:54:00.002+02:00

To export your address book from Gmail and import it into Mozilla Thunderbird:

Save your Gmail contacts as gmail-to-outlook.csv.
Select Tools | Import... from the menu in Mozilla Thunderbird.
Make sure Address Books is selected.
Click Next >.
Highlight Text file (LDIF,.tab,.csv,.txt) under Please select the program from which you would like to import.
Click Next >.
Select the gmail-to-outlook.csv file you just created.
Make sure First record contains field names is checked.
Use the Move Up and Move Down buttons to match Mozilla Thunderbird address book fields on the left with Gmail fields on the right.
- Make sure at least
- Primary Email and E-mail Address and
- Last Name and Name match.
- Gmail has a unified name field and does not distinguish between first and last names.
- You can use the Next button at the top to see what the import process will produce.
Click OK.
Now click Finish.

In your Mozilla Thunderbird address book, you will now find a folder named "gmail-to-outlook" with all imported contacts.

Source

How to Enable Ctrl + Alt + BackSpace in Ubuntu Jaunty and Karmic

2010-01-29T01:20:00.002+02:00

Method 1 (tested by me and working):

"sudo apt-get install dontzap"
"sudo dontzap -d"

Method 2 (hasn't been tested by me):

Add the following lines to your xorg.conf file, making sure that when you paste it, it is NOT using smart quotes: "sudo gksudo gedit /etc/X11/xorg.conf"

Section “ServerFlags”

Option “DontZap” “false”
EndSection
you can use "right alt" + "printscreen" + "k"
to do the same effect

Source

Update: For Karmic, you won't find that package, but there is a much simpler method:

Using GNOME
* Get to the System->Preferences->Keyboard menu.
* Select the “Layouts” tab and click on the “Layout Options” button.
* Then select “Key sequence to kill the X server” and enable “Control + Alt + Backspace”.

Source

Build your ecplise distribution

2010-01-21T11:30:00.005+02:00

You can build your eclipse distribution, you can choose from many plug-ins.
http://ondemand.yoxos.com/geteclipse/start

enjoy !

2010-01-18T22:35:00.000+02:00

How to unset environment variables in Bash

use the keyword unset :), that's it!

Change display resolution in Redhat 5 or Oracle Enterprise Linux 5

2010-01-09T03:03:00.002+02:00

Edit your "/etc/X11/xorg.conf" file, add the "Modes" part under subsection "Display" where the first mode - which is 1024x768 in the example below - will be the default one:

Section "Screen"
        Identifier "Screen0"
        Device     "Videocard0"
        DefaultDepth     24
        SubSection "Display"
                Viewport   0 0
                Depth     24
                Modes     "1024x768" "800x600" "640x480"
        EndSubSection
EndSection

Save the file, then restart your X server or restart your computer if you don't know how to :)

Source

Temporary workaround for virtualbox not able to unmount CD/DVD drive or ISO image

2010-01-08T18:29:00.002+02:00

Just don't use a dynamic expanding harddisk and the problem is gone!!

Regenerate Database Console Repository

2010-01-07T00:57:00.000+02:00

This is needed in case you misconfigured your Database console, you should rebuild it by doing the following:

Drop it: "emca -deconfig dbcontrol db -repos drop"
Recreate it: "emca -config dbcontrol db -repos create"

That's it, should be fine now :), thanks to this great post

How to solve the problems of "Oracle Enterprise Linux" in virtualbox

2010-01-06T14:53:00.001+02:00

Not able to boot:
Just press escape during the grub loading process and choose the second kernel :), that's it! If you want it to be persistent to avoid doing that at every startup, just go edit the "/boot/grub/grub.conf" and change "default=0" to "default=1" to point to the second kernel automatically.

Source

Not able to install Guest Additions:

mount the installation DVD, navigate to the folder "Server" and issue the command "rpm -ivh kernel-devel-2.6.18-164.el5.i686.rpm"
unmount the DVD (if you're not able to unmount due to a bug in virtualbox that prevents unmounting, just shutdown the guest OS and then remove it from the storage section)
In the guest OS, click "Devices"->"Install Guest Additions"
The CD will be mounted, navigate to its folder (in /media/VBox***) and run "sh VBoxLinux***x86.sh" (x86 here if you're using 32-bit edition)
Reboot and enjoy :)

The anonymity script in action :)

2010-01-02T00:29:00.000+02:00

The trick worked on my wireless router at home :), check the screenshots below:

How to draw a circle - or any other shape using selection tools - with Gimp

2010-01-02T00:18:00.001+02:00

I know it sounds a bit stupid, and it really is, but the following shows you how to draw that stupid thing:

Use any selection tool (Rectangle Select Tool, Ellipse Select Tool, Free Select Tool ...etc) and select the part you want to be surrounded by a circle for example
Click Edit->Stroke Selection

That's it! simple, isn't it?

Source

How I removed an annoying nautilus context menu item

2009-12-30T22:33:00.000+02:00

AT LAST I DID IT!!

After installing the new version of Lotus Notes, it added a stupid item to my nautilus context menu labeled "Send to Lotus Notes", this item crashes nautilus whenever it's clicked!! and it was bothering me a LOT! I googled and googled and googled and found nothing at all! Here is the bug description "http://www-10.lotus.com/ldd/nd85forum.nsf/c6054cf2ea498b338525733900559bd1/7ab83251d1d068db852575fb0036104b?OpenDocument" and here is what I did to remove that item:

Killed nautilus "killall nautilus"
In a terminal, I started nautilus again, just type "nautilus"
I reproduced the issue by clicking that item to crash nautilus
An error message appeared stating that "nautilus: symbol lookup error: /usr/lib/nautilus/extensions-2.0/libnautilus-notes-sendto.so: undefined symbol: gnome_vfs_uri_new"
I just went to the folder "/usr/lib/nautilus/extensions-2.0" and renamed the "libnautilus-notes-sendto.so" file to another name
Restarted nautilus and it's gone!

Mirage: A very simple, powerful and quick image editor in Ubuntu

2009-12-30T17:34:00.000+02:00

Since gimp is considered somehow a heavy-weight program, at least for basic image editing, I searched in Ubuntu repositories for a quicker alternative and I found "Mirage", it's very simple and contains nice features such as:

* Slideshow and fullscreen mode
* Rotating, zooming, flipping, resizing, and cropping
* Screenshot

I used it primarily for image cropping as I had to open gimp for every image I wanted to crop and that was bothering me a lot as it takes some time to startup.

How to avoid Internet Disconnection while connected to VPN on Ubuntu or any other OS

2009-12-30T03:02:00.001+02:00

I wished to have that feature since a very long time ago and at last I found a solution which was very simple! The solution idea is simple: Don't use your base OS to connect to the VPN, use a virtual machine instead, for example I use Virtualbox as my virtualization software and I have Ubuntu 9.04 as my base OS and Ubuntu 9.10 as my guest OS, I installed the Cisco-compatible vpnc and network-manager-vpnc packages, and then connected to the VPN on the guest OS and everything worked like a charm! On my base OS I can do everything I want as if I'm not connected to any VPN and my guest OS connects to the VPN and has access to all network resources there, simple, isn't it :) ?

Update: I did the same with a Windows XP guest and Cisco VPN client and it worked fine as expected.

Capslock Indicator in Ubuntu

2009-12-30T02:39:00.000+02:00

Very useful if you don't have a led on your laptop indicating whether the caps lock key is turned on or off:

"sudo apt-get install lock-keys-applet"
"killall gnome-panel"
Right click the panel, click "Add to panel" and then choose the "Lock Keys" applet
Enjoy :)

Access shared-folder in Ubuntu host from Ubuntu guest in Virtualbox

2009-12-29T23:54:00.000+02:00

This is the scenario that you run Ubuntu as your host operating system and Ubuntu guest in VirtualBox, and that you want to access a specific folder from Ubuntu host.

First you have to make sure that have install Guest Additions. From the VirtualBox's menu go to Devices → Install Guest Additions... This will mount a virtual CD on your /media/cdrom. Normally this folder's window will show up. As root run the program VBoxLinuxAdditions.run. When the program completes reboot your VirtualBox.

With Guest Additions installed you may now go ahead and define the shared folder(s). From the VirtualBox's menu go to Devices → Shared Folders. A dialog will show up. In this dialog you can specify which folder from your Ubuntu host system you want to share with your Ubuntu guest. Press the button with the + symbol to add a new shared folder in the list. You will have to specify a Folder Name for each folder you add. Make sure you memorize that name because you will need it very soon.

When done with you shared folder(s) specification, you may now go ahead and actually mount these folders from Ubuntu. First you have to create a mounpoint, that is, a directory in your Ubuntu guest which will reflect the shared folder from Ubuntu host:

# sudo mkdir /media/host-share

Of course you may choose an alternative path for your mountpoint. With your mountpoint created you can now mount the shared folder, like this:

# sudo mount -t vboxsf folder-name /media/host-share

Where folder-name will be the name you assigned for this folder when you were adding it in the shared folders list.

Source

A complete invisibility - anonymity - solution for Ubuntu

2009-12-28T20:29:00.002+02:00

Based on some online articles and my previous posts, I created the following script which does the following:

Generates and assigns a random MAC address to my wired card (eth0) and wireless card (wlan0) using the macchanger software described here
Generates and assigns a new hostname to my OS
Applies the new changes in my "/etc/hosts" file
Runs on every startup

IMPORTANT: You MUST have your "127.0.0.1" and "127.0.1.1" entries as the last two lines if you need to run this script EXACTLY as it is. If you don't want this, you can simply change the "sed" part.

Here is the script:

!/bin/bash

#random_computer_name & random MAC address for both eth0 and wlan0

sudo macchanger -A eth0 #random mac for eth0
sudo macchanger -A wlan0 #random mac for wlan0

sed -i 1,10d /etc/hostname

function randnum
{
number=$[ ( $RANDOM % 15 ) + 8 ]
}

randnum

function randpass
{
newhostname=`
}

randpass

(echo '0a'; echo $newhostname; echo '.'; echo 'wq') | ed -s /etc/hostname

/bin/hostname $newhostname

sed -i '$d' /etc/hosts # deletes the last two lines in /etc/hosts
sed -i '$d' /etc/hosts

echo -e "127.0.0.1 $newhostname localhost\n127.0.1.1 $newhostname" >>/etc/hosts

You can add the above file to your startup following the steps in this link

Appreciate any feedback. Note: I'm already working with this script on my laptop and it's working fine till now, I just had about 10 seconds idle at the startup screen.

Update: That delay happened only after the first startup and then disappeared

Delete the last line in a text file using sed

2009-12-28T20:08:00.000+02:00

sed -i '$d' hobba

-i: to change the file itself, not copy contents to another file or something
$d: delete the last line
hobba: the file name

Insert a "new line" character in a text file using Bash

2009-12-28T19:53:00.000+02:00

"echo -e "192.168.100.100\n192.168" >> hobba"

The '-e' option does the magic, as it allows escape characters to be printed

Source

How to delete certain lines of text from a file in Bash using sed

2009-12-28T19:44:00.002+02:00

"sed -i 1,+2d file_name"

deletes starting from line '1' and the next '2' lines, i.e. deletes the first 3 lines

Cleanup the SSH known_hosts file

2009-12-28T19:41:00.000+02:00

"ssh-keygen -R [host] "

helpful especially in clusters

How to randomly change your MAC address on Ubuntu

2009-12-28T18:49:00.001+02:00

"sudo apt-get install macchanger"
"sudo macchanger -A eth0"

where "eth0" is the network card you'd like to change its MAC.

Note: You have to edit your connection in Network Manager and change the old MAC with the new one, or - which is much better in my opinion - just remove the MAC from there to be obtained dynamically.

Source

Change your hostname randomly in Ubuntu

2009-12-28T18:18:00.001+02:00

The following script worked great:

#!/bin/bash

#random_computer_name

sudo sed -i 1,10d /etc/hostname

function randnum
{
number=$[ ( $RANDOM % 15 ) + 8 ]
}

randnum

function randpass
{
newhostname=`
}

randpass

(echo '0a'; echo $newhostname; echo '.'; echo 'wq') | sudo ed -s /etc/hostname

sudo /bin/hostname $newhostname

Just add the above script in a file and execute it with "sudo".

To add this file to your startup scripts, just follow the instructions in this post

Source: here

Change your computer's hostname in Ubuntu

2009-12-28T18:12:00.002+02:00

"sudo hostname new_name"

where "new_name" is the new hostname you'll use

How to change your network MAC address on Ubuntu

2009-12-28T18:06:00.000+02:00

"sudo ifconfig eth0 down" #bring down the network card

"sudo ifconfig eth0 inet hw ether xx:xx:xx:xx:xx:xx up" #change the MAC and bring it back up

where "eth0" is the network adapter you wish to change its MAC and "xx:xx:xx:xx:xx:xx" is the 6 groups of numbers each composed of two hexadecimal numbers.

For more info on MAC addresses, check this link and for the source, I got it from here, thanks to suki :)

An Excellent Solution to websites that don't save the username and password

2009-12-28T00:21:00.000+02:00

A very nice tutorial that I read here,and it then led me to here, it's a Javascript script that enables Firefox to remember usernames and passwords for some websites that orders the browser not to remember it, and I LOVE IT! It worked like a charm.

How to connect using Mobinil 3G Modem in Egypt, Solution to a problem in Ubuntu's default configuration

2009-12-22T13:34:00.000+02:00

If you create a profile in 3G connections in Ubuntu (I'm currently using version 9.04), you will be able to connect but you won't be able to reach any website, that's because of a glitch in the default configuration for "Mobinil" service provider. To solve the problem:

Right-click on the Network Manager icon and choose "Edit Connections"
Choose the "Mobile Broadband" tab
Double click the "Mobinil" connection
Open the "IPV4 Settings"
In the "Method", change from "Automatic (PPP) addresses only" to "Automatic (PPP)".
Reconnect and enjoy :)

Backup and Restore ext4 filesystem using fsarchiver

2009-12-19T08:39:00.001+02:00

Important Note: Until the time of writing this article, "partimage" DOESN'T SUPPORT EXT4, it detects ext4 as ext3 and then displays an error message saying "can't read bitmap block 0 from image", so if you use something like the bootable disk "systemrescuecd" for backup and you're using an ext4 filesystem, you'd better use another alternative such as "fsarchiver" as in the following steps:

Create a mountpoint to save the image to, e.g. "/root/backup"
"fsarchiver savefs /root/backup/backup.fsa /dev/sda1" where sda1 is the partition you wish to backup.

fsarchiver uses gzip compression by default and it will display a summary once it finishes, make sure the summary doesn't contain any errors. To restore the image:

"fsarhiver restfs /root/backup/backup.fsa id=0,dest=/dev/sda1" where "/dev/sda1" is the partition you wish to restore and "id=0" is used to indicate that it's the first partition in the list of paritions - if any - inside the "backup.fsa" file.

For more information, visit http://www.fsarchiver.org/QuickStart

UNetbootin: Burn any ISO or image files to USB Disk on Linux

2009-12-17T20:53:00.002+02:00

Go to the following URL: http://unetbootin.sourceforge.net/ and download the file
Make the file executable (chmod +x file_name)
This step is specific for Ubuntu: If you receive the message "7z not found ....", open a terminal and run "sudo apt-get install p7zip-full"

BTW, if you need to write IMG files instead on Ubuntu, you can install the USB image writer by running "sudo apt-get install usb-imagewriter"

Enjoy :)

How To Decrease Resolution of Output Video File in mencoder

2009-12-16T13:13:00.000+02:00

In a previous post, I showed how to change an .ogv file to a .avi one which is useful is you're going to give the video to a windows user. One problem I faced is that my resolution is too high and after I created the output avi file, it was about 7 MB in size which was too large as an e-mail attachment, you can simply add the parameter "-vf scale=800:600" to reduce the resolution to 800*600, e.g.

mencoder OMPerf.ogv -vf scale=800:600 -ovc xvid -oac mp3lame -xvidencopts pass=1 -o output.avi

where:

OMPerf.ogv is the input file
800*600 is the resolution
output.avi is the output file

How To Find and Delete Files Not Matching MULTIPLE criteria using bash in AIX

2009-12-14T17:18:00.000+02:00

"find . ! -name "*.bz2" ! -name "ESPRD*" | xargs rm"

The above command finds all files in the "current" directory excluding those with "*.bz2" extension and those which start with "ESPRD*" and then deletes them all.

How to add a new data file to Oracle Tablespace using sqlplus

2009-12-14T14:08:00.007+02:00

First login as the "oracle" user, and issue the command "sqlplus "/ as sysdba"" (I am assuming that you already have configured the

PATH environment variable correctly) and then type the following:

alter tablespace tablespace_name

add datafile '/oracle/data/file1.dbf' size 12G autoextend off;

The above command adds a data file named "file1.db" of size 12 GB to the "/oracle/data" path with the autoextend feature turned off

Source: http://www.adp-gmbh.ch/ora/sql/alter_tablespace.html

Convert OGV files to AVI using mencoder

2009-12-14T12:45:00.002+02:00

OGV is the default output for the "recordmydesktop" application in ubuntu, and I needed to convert it in order to use another software:

mencoder input.ogv -ovc xvid -oac mp3lame -xvidencopts pass=1 -o output.avi

Gwibber : Twitter & Facebook Client in Ubuntu 9.04

2009-12-12T18:54:00.000+02:00

A very nice desktop application for feeds from twitter and facebook, don't use the one packed with Ubuntu 9.04 and use the one from the PPA instead:

To download the new version :

open synaptic package manager
go to Settings -> Repositories
on the Third-party Software tab, click add and add this line :
deb http://ppa.launchpad.net/gwibber-team/ppa/ubuntu jaunty main
and then save this key and import it from Authentication tab to authorize it.
after that reload synaptic package manager, and then search for Gwibber. Now it has the 0.9.2 version

After installation process add Facebook account in Gwibber by :

Account -> Create -> Facebook
you'll have to Authorize Gwibber to use your Facebook account,
just follow the three easy steps and you're in.

Gwibber can also handle Twitter, account creation is very easy.

Source: http://ubuntu.igameilive.com/2009/08/gwibber-facebook-client-in-ubuntu-904.html

How to set up HP printing on Ubuntu — HP Laserjet P1005

2009-12-11T15:57:00.000+02:00

Some HP printers can use one of the drivers already installed by default in Ubuntu. In those cases, all you usually need to do is plug your printer into your computer, and Ubuntu will recognize it and prompt you to set it up. It’s super quick & easy. The HP Laserjet P1005 that I purchased needed something more. This is a good quality, small, quiet, and cheap ($75 shipped from Newegg) monochrome laser printer. It comes with drivers, Windows drivers of course, which do you no good with Ubuntu. I read that I needed hplip. Turns out that I already had hplip installed on my system by default (which will work for many HP printers), but it didn’t do me any good. I needed to download & install the newest version. Here’s how I did it…
Download the automatic installer file here, the sourceforge page for hplip. Once downloaded follow the instructions on the download page to complete the installation. It will download some more stuff, and then install everything. It will also configure your HP printer. Now you’ll have the HP Device Manager in the Accessories menu, and you’ll also have nice, smooth printing.

Source: http://howto-ubuntu.net/how-to-set-up-hp-printing-on-ubuntu/

Install Moblin 2.1 in Virtualbox

2009-12-09T14:31:00.000+02:00

I faced a problem while trying to test the new release of Moblin (2.1) which is an OS primarily designed for netbooks. When trying to boot from the live image, I get an error message stating that the kernel is not supported and that I must have something called "pae" enabled, I googled around and found what "pae" is, it's a feature in the processor and is an abbreviation for "Physical Address Extension" and here is a brief description (not quite good though) http://wiki.answers.com/Q/What_is_pae, anyway here are the steps I used to get this .img file running in my virtualbox:

Download the .img file from the website
Rename it to .iso
Assign it in the storage (as a virtual ISO CD)
Open the options for the virtual machine you've just created
Click system -> Processor -> Enable PAE.

Now you can run it and continue with the live image or installation.

Enjoy :)!

Convert IMG files to ISO in Ubuntu

2009-12-09T14:17:00.000+02:00

I searched and searched and then found what?? Just rename the file to .iso :D