bash wait for background processes in loop

Question

I want to create a for loop where I always call N functions simultaneously. They do not depend on each other, I simply want to kind of run this loop in parallel.

My idea is to call my function as a background process and after every Nth call I want to wait for all background processes.

But somehow it does not wait... I'm sure I'm missing something obvious.

#!/bin/bash

fun(){
    for i in {1..5} 
    do
        echo $i
        sleep 1s
    done
}


N=2 
(
for k in {1..8} 
do 
    ((i=i%N))
    # ((i++==0)) && (echo "waiting for all background processes" && wait) PROBLEM SOLVED:
   ((i++==0)) && echo "waiting for all background processes" && wait

    echo "i = $i"
    fun & 
done

wait
)

EDIT: it might have something to do with a subshell... I'm not sure EDIT2: yes, it was because (echo "waiting for all background processes" && wait) was executed in a subshell... that was the problem

Answer 1

I found the answer, it was due to (echo "waiting for all background processes" && wait) was executed in a subshell...

I fixed the code