I am trying to echo a variable within a printf. I first prompt the user for input using the command below
printf 'Specify lrus [default 128]: ' ;read -r lrus
Next it prompts the user again to see if he wants the input used from the previous question:
printf 'Are you sure you want $lrus lrus: ' ;read -r ans
For example the output will look like the below:
Specify lrus [default 128]: 60
Are you sure you want 60 lrus: yes
The above output is what I am trying to achieve allowing to pass the previous input variable to the next question using printf.
Your problem is that you are using single-quotes. Parameters are not expanded within single quotes.
Parameters are expanded in double-quotes, though:
printf "Are you sure you want $lrus lrus: "
If you're using a shell that supports read -p, then avoid the separate print. Supplying a prompt this way is better (it understands your terminal width, for one thing):
read -p "Specify lrus [default 128]: " -r lrus
read -p "Are you sure you want $lrus lrus? " -r ans