#!/bin/sh

val=`expr 786 + 240`
echo "Sum of 240 and 786: $val"
one= 786
two= 240
`expr $one + $two`
`expr $one - $two`
`expr $one \* $two`
`expr $one / $two`
[ $one == $two ]
[ $one -eq $two ]
[ $one -ne $two ]
[ $one -gt $two ]
[ $one -lt $two ]
[ $one -ge $two ]
[ $one -le $two ]

_______________________________________
#!/bin/sh

for i in 1 2 3 4 5
do
  echo "Looping ... number $i"
done
_______________________________________

#!/bin/sh
INPUT_STRING=hello
while [ "$INPUT_STRING" != "bye" ]
do
  echo "Please type something in (bye to quit)"
  read INPUT_STRING
  echo "You typed: $INPUT_STRING"
done

_________________________________________________
#!/bin/sh

echo "Please talk to me ..."
while :
do
  read INPUT_STRING
  case $INPUT_STRING in
    hello)
        echo "Hello yourself!"
        ;;
    bye)
        echo "See you again!"
        break
        ;;
    *)
        echo "Sorry, I don't understand"
        ;;
  esac
done
echo
echo "That's all folks!"