I have a large heirarchical directory and file structure, many levels deep with lots of subdirectories at every level. There are many more files than directories. I wanted all the files to have permissions 640 and all the directories 750.
I issued a command like this
chmod -R 640 startdir
where "startdir" was my highest level starting point for my changes. Then I had to spend 30 minutes traversing the rather large directory tree to change the permissions on all the subdirectories to 750. It was tedious. Is there another way I could have rapidly changed all the files to 640 and all the subdirectories to 750 without having to modify the subdirectories one by painful one?