1 查询目前已登录的用户信息w 或者 who
[@bjzw_11_210 ~]# w 14:03:18 up 342 days, 16:01, 2 users, load average: 0.03, 0.04, 0.00 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 10.149.239.20 Thu13 0.00s 0.19s 0.00s w guest pts/2 10.139.239.20 Thu15 22:43m 0.02s 0.02s -bash
第一行显示当前时间，开机(up)多久，几个用户在系统上的平均负载等；
第二行是各个项目（列名）的说明；
第三行以后，每行代表一个用户。如上，root登录，并取得终端机名pts/0,pts/1等。
[@tc_62_179 blog_spider]# who root pts/0 2017-12-05 09:50 (10.149.239.20) root pts/1 2017-12-07 20:41 (10.149.239.20)
2 查询每个账号最近登录时间lastlog
[@tc_62_179 blog_spider]# lastlog Username Port From Latest root pts/1 10.149.239.20 Thu Dec 7 20:41:32 +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** avahi-autoipd **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** libstoragemgmt **Never logged in** rpc **Never logged in** postfix **Never logged in** pcp **Never logged in** tss **Never logged in** unbound **Never logged in** ntp **Never logged in** rpcuser **Never logged in** nfsnobody **Never logged in** sssd **Never logged in** chrony **Never logged in** sshd **Never logged in** tcpdump **Never logged in** oprofile **Never logged in** odin pts/0 10.142.239.25 Sun Nov 12 19:50:11 +0800 2017 apache **Never logged in** netmonitor **Never logged in** guest **Never logged in** nscd **Never logged in**
本质是查看/var/log/lastlog
3 查看指定用户的属主属组等信息id
[@tc_62_179 blog_spider]# id uid=0(root) gid=0(root) groups=0(root) [@tc_62_179 blog_spider]# id odin uid=1000(odin) gid=1000(odin) groups=1000(odin),6(disk)