variable reset in a bash script
#!/bin/bash

N=0

ls -l | while read L; do
 N=$((N+1))
 echo $N
done

echo "total $N"

1
2
3

total 0

#!/bin/bash
IFS=
N=0

while read L; do
  N=$((N+1))
  echo $N
done <<<$(ls -l)

echo "total $N"