find \( -name *.m3u -o -name *.ini -o -name *.txt -o -name *.nfo -o -name *.sfv -o -name *.LOG -o -name *.ncd -o -name *.url -o -name *.exe -o -name *.qdat -o -name *.wpl -o -name *.doc -o -name *.dll \) -exec rm -i {} \; 

grep -ir string_to_search_for ./dir_to_search_in_recursively