Korn shell arithmetic operations

Some basic examples of incrementing / decrementing variables in ksh.

# decrement count from 10 to 1
count=10 ; while [[ $count -gt 0 ]] ; do echo $count ; (( count = $count -1 )) ; done

# set the value of var to 2
let "var = 1 + 1"

# set the value of var to 2
(( var = 1 + 1 ))