linux - How to duplicate string in bash? -

i have following string in bash

str="kallel" 

i want create str str2. str2 contains str duplicated till length = 20. result should this:

str2="kallelkallelkallelka" 

how in in bash?

this should work:

str="kallel" str2="${str}" while (( ${#str2} < 20 ))   str2="${str2}${str}" done str2="${str2:0:20}"