Forgotten what it was you last updated, or want to check what someone else has been updating? There’s a log file for that, and it’s located at:
/var/log/apt/history.log
To view it, run:
less
/var/log/apt/history.log
Looking for an older logfile? They’re kept, too. To see the other log files available, view the directory using ls:
ls /var/log/apt/
It should look something like:
history.log history.log.1.gz history.log.2.gz history.log.3.gz history.log.4.gz term.log term.log.1.gz term.log.2.gz term.log.3.gz term.log.4.gz
One further note – This will show the most recent things done with apt, not just upgrades.