#!/bin/sh
    x=1
    x=`expr $x + 1`
    echo $x
    x=`expr 2 + 3 \* 5`
    echo $x
    echo `expr length "cat"`
    echo `expr substr "donkey" 4 3`
    echo `expr index "donkey" "key"`
    echo `expr match "smalltalk" '.*lk'`
    echo `expr match "transputer" '.*lk'`
    echo `expr "transputer" : '.*lk'`