Getting Compaq CQ62 internal speakers working

Sound does not work from the internal speakers of Cq62 laptop using Ubuntu 10.04.for getting the sound give following command and reboot:

sudo apt-get install linux-backports-modules-alsa-lucid-generic

change the settings in alsa-mixer and enjoy

Joining splitted files in lunux

1 Hjsplit files:
hjsplit(for windows) software files into small sizes which can be joined later to get original file. we can join these files on linux through command line without any software.

say we have following files in /home/user/Downloads folder

aaa.avi.001
aaa.avi.002
aaa.avi.003

we want to join these files to get aaa.avi file, go to download folder
cd Downloads

use Concatenate FILE(s) command

cat aaa.avi.001 aaa.avi.002 aaa.avi.003 > aaa.avi

it will join all these files and give output aaa.avi file

2 RAR files
**********
EDIT:
just extract the first file aaa.part1.rar, remaining files would be joined automatically.
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for files splitted with winrar we need software called rar, so install it

sudo apt-get install rar

say we have following files in /home/user/Downloads folder

aaa.part1.rar
aaa.part2.rar
aaa.part3.rar

we want to join these files to get aaa.avi file, go to download folder

cd Downloads

use rar command

rar x -y aaa.part1.rar

it will join all these files and give output aaa.avi file

Removing pppoeconf settings

I was having broadband connection, which i configured using pppoeconf command. now i configured my modem in always on. but i was unable to edit network settings of pc (as now i have to use dynamic ip). so following worked for restoring settings:
To have NetworkManager manage all interfaces without editing ifupdown/interfaces files, this should work.
Check /etc/network/interfaces.

Open Terminal and give command

gksudo gedit /etc/network/interfaces

Remove everything but

auto lo
iface lo inet loopback

Then Check /etc/NetworkManager/nm-system-settings.confOpen Terminal and give command
gksudo gedit /etc/NetworkManager/nm-system-settings.conf
Remove everything but
[ifupdown]
managed=false

Restart computer or NetworkManager service.
From now on, only configure the network using the NetworkManager applet in the notification area (aka system tray).

For more info See: http://wiki.debian.org/NetworkManager

Playing VCD files in ubuntu

for playing VCD files (*.dat) in ubuntu ffmpeg software is required
go to
system > administration > synaptic package manager

search for ffmpeg and install it or run on terminal
sudo apt-get install ffmpeg

PS: files from VCD can not be copied in linux. so you have to copy *.dat files in windows. follow this procedure for playing the files in linux (already copied in windows)

Enabling medibuntu repository

Medibuntu (Multimedia, Entertainment & Distractions In Ubuntu) is a repository of packages that cannot be included into the Ubuntu distribution for legal reasons (copyright, license, patent, etc). Some of these packages include the libdvdcss package from VideoLAN and the external binary codecs package (commonly known as w32codecs) used by MPlayer and xine.

This command should be run in the Terminal (Applications → Accessories → Terminal):

sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update

Changing ownership of files using chown command

chown command is used for changing ownership of files, for help run in terminal


chown --h

Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...

for example : if ownership of files under folder /home/xyzabc/Pictures (including subdirectories) has to be assigned to user "xyzabc" 

sudo chown -R xyz /home/xyzabc/Pictures

where -R means recursive - operate on files and directories recursively