First, cd
into the folder that permissions will be changed.
find . -type d -exec chmod 0755 {} \; && find . -type f -exec chmod 0644 {} \;
find . -type d -exec chmod 0775 {} \; && find . -type f -exec chmod 0664 {} \;
sudo find . -type d -exec chmod 0755 {} \; && sudo find . -type f -exec chmod 0644 {} \;
sudo find . -type d -exec chmod 0775 {} \; && sudo find . -type f -exec chmod 0664 {} \;