一 查看登录用户信息
w 用户名
who 用户名
last
last默认是读取/var/log/wtmp文件数据
lastlog
lastlog命令默认是读取/var/log/lastlog文件内容
二 实战
[root@localhost media]# w
11:56:39 up 4:13, 2 users, load average: 0.00, 0.01, 0.05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 192.168.0.101 10:09 7.00s 0.49s 0.05s w
root tty1 11:56 7.00s 0.13s 0.13s -bash
[root@localhost media]# who
root pts/0 2017-07-15 10:09 (192.168.0.101)
root tty1 2017-07-15 11:56
[root@localhost media]# last
root tty1 Sat Jul 15 11:56 still logged in
root pts/0 192.168.0.101 Sat Jul 15 10:09 still logged in
root pts/0 192.168.0.101 Sat Jul 15 07:48 - 10:08 (02:19)
(unknown :0 :0 Sat Jul 15 07:44 - 09:46 (02:01)
reboot system boot 3.10.0-327.el7.x Sat Jul 15 07:43 - 12:01 (04:18)
root pts/0 192.168.0.101 Fri Jul 14 19:22 - down (02:08)
(unknown :0 :0 Fri Jul 14 19:12 - 21:30 (02:18)
reboot system boot 3.10.0-327.el7.x Fri Jul 14 19:11 - 21:30 (02:19)
root pts/0 192.168.0.100 Thu Jul 13 21:11 - down (00:16)
[root@localhost media]# lastlog
Username Port From Latest
root tty1 Sat Jul 15 11:56:33 +0800 2017
bin **Never logged in**
daemon **Never logged in**
adm **Never logged in**
lp **Never logged in**
sync **Never logged in**
shutdown **Never logged in**
halt **Never logged in**
mail **Never logged in**
operator **Never logged in**
games **Never logged in**
ftp **Never logged in**
nobody **Never logged in**
systemd-bus-proxy **Never logged in**
systemd-network **Never logged in**
dbus **Never logged in**
polkitd **Never logged in**
abrt **Never logged in**
unbound **Never logged in**
tss **Never logged in**
colord **Never logged in**
usbmuxd **Never logged in**
geoclue **Never logged in**
rpc **Never logged in**
rtkit **Never logged in**
chrony **Never logged in**
radvd **Never logged in**
qemu **Never logged in**
avahi-autoipd **Never logged in**
setroubleshoot **Never logged in**
rpcuser **Never logged in**
nfsnobody **Never logged in**
saslauth **Never logged in**
libstoragemgmt **Never logged in**
pulse **Never logged in**
gdm :0 Sat Jul 15 07:44:46 +0800 2017
gnome-initial-setup **Never logged in**
avahi **Never logged in**
sshd **Never logged in**
postfix **Never logged in**
ntp **Never logged in**
tcpdump **Never logged in**
cakin24 :0 Sat Nov 12 10:37:40 +0800 2016