chmod by type (directory and file permission)

To change permission by type (directory or file), the easiest way can do it is using find command and do something as a follow up action.
 

To change permission for file by 0664,

find ./ -type f -exec chmod -v 0664 {} \;

Note that you should put space between {} and \

To change permission for directory by 0775

find ./ -type d -exec chmod -v 0775 {} \;

To change permission for some files like "*.php"

find ./ -type f -name "*.php" -exec chmod 0664 -v 0664 {} \;

To change permission except some files like "*.log"

find ./ -type f \! -name "*.log" -exec chmod 0664 -v 0664 {} \;