Let's say I have an FTP user that I have given access to public_html, but I don't want them to have access to a certain folder within public_html. Is there a way to block their access from this certain folder, but let them have access to everything else?
You could change the owner and group of the sub folder, then chmod the "other" permissions to 0
To answer your comment. Say I have user A who you want to have access to folder A but not Folder B under it
Under folderA is folder B
So drwxr-xr-x is read as "It's a directory" The owner (UserA) has RWX the group (UserA) has RX and everyone else (other) has RX
The last part tells you that if the person is not UserA and not in the UserA group they still have R to the folder.
If you changed the permissions to look like this:
User A still has everything they need for accessing that folder.
Now User A cannot access FolderB. you would accomplish this by :
The 750 Says Owner has RWX, Group has RX and Everyone else (other) has no rights to this folder.