查看登陆成功日志

last
last -f /var/log/wtmp

清空日志

> /var/log/wtmp

查看登陆失败日志

lastb
last -f /var/log/btmp

grep -i failed /var/log/secure
grep failed /var/log/secure | cut -d' ' -f12 | uniq -c

清空日志

> /var/log/btmp