Local variables after loop exit

Question

I am having some issues with local variables after exiting a loop. The variable max ends up with the value 0, despite the code below:

max=0
cat          


        

Answer 1

The pipe before your while is putting everything inside the loop into a separate shell, and thus a separate identifier context (essentially a new environment).

Redirecting the tmp file into the while loop via < will keep your loop and variables all in the same execution context.

while read line
do
    # your loop stuff 
done < tmp