Mastering Linux Shell Scripting

Nested loops

Nested loops means loops inside loops. Check out the following example:

#!/bin/bash 
for (( v1 = 1; v1 <= 3; v1++ )) 
do 
   echo "First loop $v1:" 
   for (( v2 = 1; v2 <= 3; v2++ )) 
   do 
         echo " Second loop: $v2" 
   done 
done 

The first loop hits first, then the second loop, and this happens three times.