how to find and remove files

find -iname "*open*" -and -name "*[1,3,5,7,9]_open.txt" | wc -w

find -empty

find -newer yesterday.txt

find -mmin 30 # exactly 30 min
find -mmin +30 # greather than 30 min
find -mmin -30 # less than 30 min
find -mtime -5 # less than 5 hours
find -mtime +5 # greather than 5 hours
find -atime -5 # less than 5 hours
find -atime +5 # greather than 5 hours

find -empty -exec rm '{}' ';'
find ~ -name "*.txt" ! -empty -type f -exec grep -l "grass" '{}' ';'
find -empty | xargs ls-l