On the command line, uses `find` and `iconv` to convert certain files from ISO-8859-1 to UTF-8 (make sure the original files are indeed in ISO-8859-1).

convert_to_utf8.bash

#!/usr/bin/bash

find ./ -name '*.php' -o -name '*.html' -o -name '*.css' -o -name '*.js'  -type f |
while read file
do
  echo " $file"
  mv $file $file.icv
  iconv -f ISO-8859-1 -t UTF-8 $file.icv > $file
  rm -f $file.icv
done