Usage: frename [-iv] [-Re] 'oldstring/newstring' files
       frename [-iv] [-Re] 'perl-code' files
       frename [-iv] [-luUs] [-18] [-Re] [-dD] files
Options: -i  interactive mode: prompt for each file
         -v  verbose mode
         -l  translate to lower case
         -u  translate to upper case
         -U  translate URL-encoded characters
         -s  substitute shell-problematic characters
         -1  encode from UTF-8 to ISO-Latin-1
         -8  encode from ISO-Latin-1 to UTF-8
         -d  add date
         -D  add date+time
         -R  recursive into directory tree
         -e  edit filenames
Examples: frename '.tar.gz/.tgz' *tar.gz