Search for the case insensitive pattern 'search for me' in all files with '.p', '.w' and '.i' extension under current directory tree without descending into '.svn' and 'pdv' directories
find . \( \( -name .svn -o -name pdv \) -type d -prune \) -o \( -name '*.[pwi]' -type f -exec grep -i -l "search for me" {} + \)