# Run as root, of course.
# For sh shells:
cd /var/log
: > messages
: > wtmp
echo "Log files cleaned up."
# For bash shells:
cd /var/log
> messages
> wtmp
echo "Log files cleaned up."
# This is a better version, does the same thing, less redundancy.
# visit this link for detailed explanation:
https://superuser.com/questions/849413/why-would-you-cat-dev-null-var-log-messages