Comment by aaaaaaaaaaab

Some additional tips:

1. You don't need the parentheses.

2. If you use process substitution [1] instead of a pipe, you will stay in the same process and can modify variables of the enclosing scope:

    i=0
    while read -r v; do
        ...
        i=$(( i + 1))
    done < <(do_something)

The drawback is that this way `do_something` has to come after `done`, but that's bash for you ¯\_(ツ)_/¯

[1] https://www.gnu.org/software/bash/manual/html_node/Process-S...