Splitting a line into words in bash

Question

I would like to split a line into words. I know this can be done with this

For word in $line; do echo $word; done  

But I want to make group of 3-3 words. So my question is, how can I split a line in group of 3-3 words ?

For example

Input : I am writing this line for testing the code.  

Output :  
I am writing
this line for
testing the code.  

Answer 1

Read the words three at a time. Set the line being read from to the remainder:

while read -r remainder
do
    while [[ -n $remainder ]]
    do
        read -r a b c remainder <<< "$remainder"
        echo "$a $b $c"
    done
done < inputfile