How to install .tar.gz in ubuntu

For example you want to install vlc.tar.gz file in ubuntu then first you need to extract this .tar.gz file using the following command

$ tar -xvzf vlc.tar.gz

one folder will be created with name vlc, go to this folder  and now run these commands

$./configure
$make
$make install

if any dependency error message is shown then resolve that dependency and then run
$make
$make install

What is LPR command in linux

lpr command is used to give file for printing to the destined printer.
there are few options for lpr command

-P prints file to the named printer or give address of printer

-# sets number of copies to be printed between 1 to 100

for example
lpr -P addressofprinter -# 4 filename1 filename2

you can print multiple files at a time. number after -# is number of copies to be printed.

What is grep command: linux

   grep command is used to search a particular pattern in the given input.
for example in snap shot.
first we display content using cat just to check file content

$cat  filename

then give any word which you want to search

$grep "string-name" filename

this displays the entire line in which this string-name appears
if you want to search case insensitve word then just put option -i

$grep -i "string-name" filename

if some word is not found in file then it displays nothing

for  more details about grep you can go to manual page entry by running

$man grep

I Accidentally Removed "/usr/sbin" : How to recover it in Linux

whenever you run rm command be carefull.first run ls and see what are the files and folders going to be deleted.then only run rm.rm * deletes all the contents in current directory.which may destroy your system.

some possibilities to recover deleted directory /usr/bin :it contains all system binary files.

1> go to rescue mode and try to restore. or upgrade using CD/DVD.
or
2>try copying the same directory /usr/sbin from some other operating system(prefer the same Operating System and (if possible)same version )

to copy the directory
1> go to terminal during system boot
2>run su
3>run cp xyz /usr/
where xyz is path for the directory sbin

How to Count no. of files/directory in a directory

Steps are mentioned in snapshot , To count no of files/directory in a directory
> go to directory (here DistSys) in which you have to find no. of files and folders
>now run ls command and pipe it's output to command " wc -l "

cd DistSys
then
ls | wc -l

which gives a number say 11 ,which means directory DistSys contains 11 files or folders.

How to create your own command in linux

If you want to add your own command in linux operating system then

write any script.for example i want to add command which displays present

working directory with list of files or folders under it.then type following in gedit or any editor

#!/bin/bash

echo "present directory is `pwd` "

echo "files are `ls` "

save it with any name say pwdfiles

now make it executable

chmod +x pwdfiles

now copy it to /usr/bin directory.

cp pwdfiles /usr/bin/

How to set Default Boot Option to Windows OS or Vista

To set Default Boot option to any operating system say xyz you need to edit grub.cfg file
which resides under /boot/grub directory.
boot screen will look like this...


and each options are numbered from 0 to n( 7 here )

Ubuntu,with linux 2.6.35-23-generic =0
Ubuntu,with linux 2.6.35-23-generic(recovery mode)=1
Ubuntu,with linux 2.6.35-22-generic =2
Ubuntu,with linux 2.6.35-22-generic(recovery mode)=3
Memory test (memtest86+) =4
Memory test(memtest86+,serial console 115200) =5
Windows Vista (loader) (on /dev/sda1) =6
Windows Vista (loader) (on /dev/sda2) =7

now in grub.cfg file set default="7" to keep default boot windows vista
and to keep ubuntu as default boot
set default="0"