OS_lab week3

                                OS SHELL SCRIPTING

Write and execute shell scripts for the following (Using if, while, until and break statements):

Input two numbers. Compare them using if statement and output their relative magnitudes.

#!/bin/bash

echo "enter the two numbers"

read num1 num2

if [ $num1 -lt $num2 ]

then

echo "num1 is smaller then num2 by `expr $num2 - $num1`"

elif [ $num1 -gt $num2 ]

then

echo "num2 is greater then num1 by `expr $num1 - $num2`"

fi

Input two numbers. Display all numbers between (including) them using while statement. Calculate their sum using until statement and display it.

#!\bin\bash

echo "enter the two numbers till you want to get addition"

read first_num

read second_num

sum=0

i=$first_num

while [ $i -le $second_num ]

do

echo $i

i=`expr $i + 1`

done

i=0

sum=0

until [ $i -gt $second_num ]

do

sum=`expr $sum + $i`

i=`expr $i + 1`

done

echo "total of given number is $sum"

Write and execute shell scripts for the following (Using case statement): 

Input a number. Output whether it is zero or non-zero

#!/bin/bash

echo "enter the number to check wheter it is zero or non-zero"

read num

case $num in [0])

echo "$num is equal to zero"

;;

*)

echo "$num equal to non-zero"

;;

esac

Input a character. Output whether is an upper-case alphabet, a lower-case alphabet, a digit or a special character.

#!/bin/bash

echo "enter input to check upper case or lower case or number or spical charecter"

read num

case $num in [A-Z])

echo "$num is upper case"

;;

[a-z])

echo "$num is lower case"

;;

[0-9])

echo "$num is number"

;;

*)

echo "$num is special case"

;;

esac