How do I get the name of the active user via the command line in OS X?

Question

How do I get the name of the active user via the command line in OS X?

Answer 1

The question has not been completely answered, IMHO. I will try to explain: I have a crontab entry that schedules a bash shell command procedure, that in turn does some cleanup of my files; and, when done, sends a notification to me using the OS X notification center (with the command osascript -e 'display notification ...). If someone (e.g. my wife or my daughter) switches the current user of the computer to her, leaving me in the background, the cron script fails when sending the notification.

So, Who is the current user means Has some other people become the effective user leaving me in the background? Do stat -f "%Su" /dev/console returns the current active user name?

The answer is yes; so, now my crontab shell script has been modified in the following way:

...
if [ "$(/usr/bin/stat -f ""%Su"" /dev/console)" = "loreti" ]
then /usr/bin/osascript -e \
  'display notification "Cleanup done" sound name "sosumi" with title "myCleanup"'
fi