Two useful perl one-liners for searching and replacing
To change a string in all files in the current directory and below
find |xargs perl -pi -e 's/searchpat/replacepat/g'
Examples:
find -name "*.py"|xargs perl -pi -e 's/searchpat/replacepat/g'
find -name "*.pt"|xargs perl -pi -e 's/searchpat/replacepat/g'
To change the names of files in current directory and below
find|perl -nl -e '$o= $_;rename($o,$_) if s/searchpat/replacepat/'