Change ownership of all files, from one owner to another I changed the shortname of my user account, but it seems to have caused an issue with some files (especially homebrew stuff), which are still owned by the old username. My old short name was cannyboy, and my new one is cannyman. How would I go thru the whole hard drive and change ownership of all cannyboy to cannyman, without changing any other attributes of the files?
As starter I would suggest you run the "repair permission" function in disk utility.

If the problem still persists you could run a command like:

find . -user old_user | while read file; do echo chown new_user  $file; done


note: this doesn't do anything as is now - you will need to adjust it to your needs - and make sure it does nothing bad.

update learnt some more and now I would run a command like this:

find . -user old_user -print0 | xargs -0  sudo echo chown new_user


again adjust the command before you run it!