Simple Calculator Shell Programming | os | 4th sem cse | operating system lab | QT
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operating system laboratory for cse engineering playlist
• Operating System
Exp. No. 4 Simple Calculator Shell Programming
Aim
To write simple shell scripts using shell programming fundamentals.
The activities of a shell are not restricted to command interpretation alone. The shell
also has rudimentary programming features. Shell programs are stored in a file (with
extension .sh). Shell programs run in interpretive mode. The original UNIX came with the
Bourne shell (sh) and it is universal even today. C shell (csh) and Korn shell (ksh) are also
widely used. Linux offers Bash shell (bash) as a superior alternative to Bourne shell.
F) Simple Calculator
Arithmetic operations — calc.sh
echo -n "Enter the two numbers : "
read a b
echo " 1. Addition"
echo " 2. Subtraction"
echo " 3. Multiplication"
echo " 4. Division"
echo -n "Enter the option : "
read option
case $option in
1) c=`expr $a + $b`
echo "$a + $b = $c";;
2) c=`expr $a - $b`
echo "$a - $b = $c";;
3) c=`expr $a \* $b`
echo "$a * $b = $c";;
4) c=`expr $a / $b`
echo "$a / $b = $c";;
*) echo "Invalid Option"
esac
Output
$ sh calc.sh
Enter the two numbers : 2 4
1. Addition
2. Subtraction
3. Multiplication
4. Division
Enter the option : 1
2 + 4 = 6