#!/bin/bash

d=$(mktemp -d -t) || exit
cd "$d"

printf 'no eol' >first
printf 'no final eol\nnot here' >second
printf 'has eol\n' >third
printf 'has eol\ntoo\n' >fourth


for f in *; do
    diff -u /dev/null "$f"
done

printf '%s\n' '------------------'

for f in *; do
    awk 1 "$f" >tmp
    cmp -s tmp "$f" || mv tmp "$f"
done
rm -f tmp

for f in *; do
    diff -u /dev/null "$f"
done