sh Arithmetic Expansion Parameter Expansion


Example

Loop n times:

while [ $((i=${i:=0}+1)) -le "$n" ]; do
    echo line $i
done

Output for n=5:

line 1
line 2
line 3
line 4
line 5

Manipulating decimals:

$ i=3.14159; echo $((${i%.*}*2))
6
$ i=3.14159; echo $((${i#*.}*2))
28318