# Created on savesnippets.com · https://savesnippets.com/2HmRL4aoiNfPNN
while IFS= read -r line; do
    echo "got: $line"
done < /etc/hosts

# Read AND track line numbers
n=0
while IFS= read -r line; do
    ((n++))
    printf '%4d  %s\n' "$n" "$line"
done < /etc/hosts

# Process stdin instead of a file
some_command | while IFS= read -r line; do
    echo "stdin: $line"
done
# WARNING: piping into `while` runs the loop in a subshell —
# variable changes won't survive. Use process substitution:
while IFS= read -r line; do
    count=$((${count:-0} + 1))
done < <(some_command)
echo "total: $count"