Category Archives: Operating System

Bash For Loops

Posted on August 6, 2015 | Leave a comment

Syntax:

for var in <list>
do
<commands>
done

for var in <list>

done

example:

named='Zaki Live .Com'
for nametame in $named
do
echo $nametame
done

named='Zaki Live .Com'

for nametame in $named

echo $nametame

done

we can check at the end that loop is not working by this

named='Zaki Live .Com'
for nametame in $named
do
echo $nametame
done
echo Voila La La

named='Zaki Live .Com'

for nametame in $named

echo $nametame

done

echo Voila La La

Another examples can be c like styles:

for (( c=1; c<=5; c++ ))
do
   echo "Welcome $c times"
done

for (( c=1; c<=5; c++ ))

echo "Welcome $c times"

done

Bash IF Else with for loop break and continue have to practice later time 🙂

Here is the video all for loop explained beautifully

References:

http://www.cyberciti.biz/faq/bash-for-loop/

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Posted in A ll Codes, Bash/Shell Scripting

Tagged for loops

Bash Programming : Say user hello !

Posted on August 1, 2015 | Leave a comment

Take a name from user and say hello user! 😀

echo `expr "What is your name?"`
read a
echo `expr "Hello $a"`

echo `expr "What is your name?"`

read a

echo `expr "Hello $a"`

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Posted in A ll Codes, Bash/Shell Scripting

Tagged hello

Bash Programming : Check typed name is a valid $USER or not

Posted on August 1, 2015 | Leave a comment

I tried it hardly….Here you have to maintain the syntax

if[expression]
then
echo expr ""Hello Name
fi

and this conditional

if [ “foo” = “foo” ]; then
echo expression evaluated as true
fi

or the same things can be written as

if[ “foo” = “foo” ]
then
echo expr "Hello !"
fi

if..then..else in bash

if [ “zaki” = “live” ]
then
echo expr "True !" else echoexpr “False!”

conditional with variables t1="zaki" t2="live" if [ "$t1" = "t2" ] then echoexpr “True” else echoexpr “False”`
fi #you have to end with this if you started with if

echo `expr "What's your name?"`
read name
if [ "$name" = "$USER" ] 
then
 echo `expr "Hello $name"`
else
 echo `expr "You are not valid user!"`
fi

echo `expr "What's your name?"`

read name

if [ "$name" = "$USER" ]

then

echo `expr "Hello $name"`

else

echo `expr "You are not valid user!"`

Reference: http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-6.html#ss6.1
http://ryanstutorials.net/bash-scripting-tutorial/bash-if-statements.php

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Posted in A ll Codes, Bash/Shell Scripting

Tagged bash, hello, name, user

Bash Programming : Multiplication

Posted on August 1, 2015 | Leave a comment

Here I tried this on ubuntu

To create the file

cat>mul

cat>mul

code type in the terminal:

read a
read b
mul=`expr $a "*" $b`
echo $mul

read a

read b

mul=`expr $a "*" $b`

echo $mul

save the file and close editing mode:

ctrl+d

ctrl+d

change the permission of this file:

chmod +x mul

1	chmod +x mul

to show the output

sh mul
4
5
20

sh mul

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Posted in A ll Codes, Bash/Shell Scripting

Tagged bash, multiplication

Bash Programming : Addition

Posted on August 1, 2015 | Leave a comment

Here I tried this on ubuntu

To create the file

cat>add

cat>add

code type in the terminal:

read a
read b
sum=`expr $a + $b`
echo $sum

read a

read b

sum=`expr $a + $b`

echo $sum

don’t give space after or before equal sign

save the file and close editing mode:

ctrl+d

ctrl+d

change the permission of this file:

chmod +x add

1	chmod +x add

to show the output

sh add
4
5
9

sh add

Shortcut method for addition or any other:
create a file with cat then type code from the below in one line

echo `expr $1 + $2 + $3`

1	echo `expr $1 + $2 + $3`

here 1 2 and 3 is variable is taking input from user and also giving teh output so we sue $ before them….it is the shortcut method

then just type

sh shortcut 3 4 5

1	sh shortcut 3 4 5

and you will get the addition of this variables

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Posted in A ll Codes, Bash/Shell Scripting

Tagged add, addition, bash/shell, terminal

Hibernate or Sleep which is best ?

Posted on August 1, 2015 | Leave a comment

From my point of view and by searching various websites I have found that

Hibernate is good that it resume all of your work after an extended period of time…..And do not use any power while close

and For sleep it can be use for shortest period of time and it uses some power while close…

So hibernate is good from the comparison and my personal experience

But we have to be cautious not to do those things too much Hibernate or Sleep that can sometimes causes the damage for hard disk if power interruption or any misinterpretation happens.

References: http://www.howtogeek.com/102897/whats-the-difference-between-sleep-and-hibernate-in-windows/

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Posted in Operating System, Tech Tips, Techie Talk

Tagged hibernate, os, sleep mode, ubuntu, windows

Odd Even in Bash/Shell Scripting

Posted on July 25, 2015 | Leave a comment

I tried it so many times but it didn’t gave the solution but the code I have found on the net and I understood where my problem was

echo -n "Enter numnber : "
read number
 
remainder=$(( $number % 2 ))
 
if [ $remainder = 0 ]
then
  echo "$number is even number"
else
  echo "$number is odd number"
fi

echo -n "Enter numnber : "

read number

remainder=$(( $number % 2 ))

if [ $remainder = 0 ]

then

echo "$number is even number"

else

echo "$number is odd number"

caution: Don’t forget to give space after if eg. if [ ] and symbols eg. [ $remainder = 0 ]

and don’t forget to style after then eg.

then
echo “$number is evern”
else
echo “$number is odd”

if you don’t do all of the above mentioned system will give various errors.

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Posted in A ll Codes, Bash/Shell Scripting

Tagged bash/shell, bourne, oddeven, programming, scripting, ubuntu, unix

CPU Scheduling: Round Robin Algorithm

Posted on July 13, 2015 | Leave a comment

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Posted in CPU Scheduling, Operating System

Fixing Master Boot Recrord(MBR) issue with BIOS and Windows 7

Posted on June 18, 2015 | Leave a comment

Insert Windows 7 DVD in the DVD – ROM
then Keep Nexting and Repair Windows option will come then you have to click comamnd prompt when system recovery option comes then click bootrec

>bootrec /fixmbr

and enter then type >exit

then just restart the system

Boot screen will be back again 🙂

This video helped me a lot by showing how the command perform