Here I tried this on ubuntu
To create the file
cat>add
code type in the terminal:
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
change the permission of this file:
chmod +x add
to show the output
sh add 4 5 9
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`
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
and you will get the addition of this variables
