Add encoding headers to Ruby files

add_encoding_headers.sh

find -name "*.rb" | \
while read filepath; do \
{ echo -n "$filepath: "; head -n1 "$filepath"; } | \
grep -v encoding | sed -e "s#.*#$filepath#"; \
done | \
while read filepath; do \
{ echo "# encoding: UTF-8"; echo; } | \
cat - "$filepath" > "$filepath.tmp"; \
mv "$filepath.tmp" "$filepath"; \
done