How to chown/chmod all files in current directory?

You want to use chown username:groupname *, and let the shell expand the * to the contents of the current directory. This will change permissions for all files/folders in the current directory, but not the contents of the folders.

You could also do chown -R username:groupname ., which would change the permissions on the current directory, and then recurse down inside of it and all subfolders to change the permissions.

chown -R username:groupname * will change the permissions on all the files and folders recursively, while leaving the current directory itself alone. This style and the first style are what I find myself using most often.

I think you want this:

chown username:groupname *

If you also want to recursively change subdirectories, you'll need the -R (-r is deprecated) switch:

chown -R username:groupname *