last
功能說明：
列出目前與過去登入系統的用戶相關信息
語法：
last [-adRx] [-f] [-n] [帳號名稱] [終端機編號..]
補充說明：
單獨執行last指令，它會讀取位於/var/log目錄下，名稱爲wtmp的文件，並把該給文件的內容記錄的登入系統的用戶名單全部顯示出來
參數：
-a ：把從何處登入系統的主機名稱或IP地址，顯示在最後一行
-d ：將IP地址轉換成主機名稱
-f ：指定記錄文件
-n ：設置列出名單的顯示列數
-R ：不顯示登入系統的主機名稱或IP地址
-x ：顯示系統關機，重新開機，以及執行等級的改變等信息
命令實踐：
[root@yubing ~]# last
yubing pts/0 10.0.0.112 Mon May 6 13:06 still logged in
yubing pts/0 10.0.0.112 Mon May 6 13:05 - 13:06 (00:00)
yubing pts/0 10.0.0.112 Mon May 6 18:42 - 13:04 (-5:-37)
root tty1 Mon May 6 18:41 still logged in
reboot system boot 2.6.18-194.el5 Mon May 6 18:41 (-1:-43)
yubing pts/0 10.0.0.112 Mon May 6 01:45 - 20:05 (-5:-39)
root tty1 Mon May 6 01:45 - crash (16:56)
reboot system boot 2.6.18-194.el5 Mon May 6 01:45 (15:12)
yubing pts/0 10.0.0.112 Sun May 5 12:54 - crash (12:51)
yubing pts/0 10.0.0.112 Sun May 5 12:43 - 12:53 (00:10)
yubing pts/0 10.0.0.112 Sun May 5 16:39 - 12:43 (-3:-56)
root tty1 Sun May 5 16:39 - crash (09:06)
reboot system boot 2.6.18-194.el5 Sun May 5 16:37 (1+00:20)
yubing pts/0 10.0.0.131 Sun Apr 21 19:30 - 20:00 (00:29)
yubing pts/0 10.0.0.131 Sun Apr 21 16:25 - 19:30 (03:05)
yubing pts/0 10.0.0.131 Sun Apr 21 14:09 - 16:24 (02:15)
yubing pts/0 10.0.0.131 Sun Apr 21 08:55 - 12:54 (03:59)
root tty1 Sun Apr 21 16:54 - crash (13+23:42)
reboot system boot 2.6.18-194.el5 Sun Apr 21 16:52 (15+00:04)
yubing pts/0 10.0.0.131 Fri Apr 19 23:06 - 17:40 (-5:-25)
root tty1 Fri Apr 19 23:05 -crash (1+17:46)
reboot system boot 2.6.18-194.el5 Fri Apr 19 23:05 (16+17:52)
reboot system boot 2.6.18-194.el5 Fri Apr 19 03:48 (17+13:08)
yubing pts/0 10.0.0.131 Fri Apr 19 00:14 - 18:59 (-5:-15)
root tty1 Fri Apr 19 00:14 -crash (03:34)
reboot system boot 2.6.18-194.el5 Fri Apr 19 00:14 (17+16:43)
root tty1 Thu Apr 18 14:35 -crash (09:38)
reboot system boot 2.6.18-194.el5 Thu Apr 18 22:34 (17+18:23)
yubing pts/0 10.0.0.131 Thu Apr 18 13:02 - 14:18 (01:16)
root tty1 Thu Apr 18 13:01 -crash (09:33)
reboot system boot 2.6.18-194.el5 Thu Apr 18 20:59 (17+19:57)
yubing pts/0 10.0.0.131 Thu Apr 18 19:31 - 12:16 (-7:-14)
root tty1 Thu Apr 18 19:30 -crash (01:29)
reboot system boot 2.6.18-194.el5 Thu Apr 18 19:30 (17+21:27)
root tty1 Thu Apr 18 03:54 -crash (15:35)
reboot system boot 2.6.18-194.el5 Thu Apr 18 03:54 (18+13:03)
yubing pts/0 10.0.0.131 Thu Apr 18 01:12 - 18:04 (-7:-8)
root tty1 Thu Apr 18 01:12 - crash (02:41)
reboot system boot 2.6.18-194.el5 Thu Apr 18 01:12 (18+15:45)
yubing pts/0 10.0.0.131 Wed Apr 17 14:18 - 16:31 (02:13)
yubing pts/0 10.0.0.131 Wed Apr 17 20:58 - 14:18 (-6:-40)
root tty1 Wed Apr 17 20:57 -crash (04:14)
reboot system boot 2.6.18-194.el5 Wed Apr 17 20:55 (18+20:02)
yubing pts/0 10.0.0.131 Wed Apr 17 18:49 - 20:11 (01:22)
root tty1 Wed Apr 17 18:49 -crash (02:06)
reboot system boot 2.6.18-194.el5 Wed Apr 17 18:48 (18+22:08)
reboot system boot 2.6.18-194.el5 Tue Apr 16 21:53 (19+19:04)
yubing pts/0 10.0.0.131 Tue Apr 16 00:36 - 01:55 (01:19)
root tty1 Tue Apr 16 00:35 -crash (21:17)
reboot system boot 2.6.18-194.el5 Tue Apr 16 00:33 (20+16:23)
yubing pts/0 10.0.0.131 Mon Apr 15 19:05 - crash (05:28)
root tty1 Mon Apr 15 19:05 -crash (05:28)
reboot system boot 2.6.18-194.el5 Mon Apr 15 19:05 (20+21:52)
yubing pts/1 10.0.0.131 Mon Apr 15 03:43 - 03:50 (00:07)
yubing pts/1 10.0.0.131 Mon Apr 15 03:34 - 03:43 (00:08)
root pts/1 10.0.0.131 Mon Apr 15 02:20 - 03:33 (01:13)
root pts/1 10.0.0.131 Mon Apr 15 02:08 - 02:08 (00:00)
root pts/1 10.0.0.131 Mon Apr 15 02:00 - 02:07 (00:07)
root pts/0 10.0.0.131 Mon Apr 15 01:56 - crash (17:08)
root pts/0 10.0.0.131 Mon Apr 15 01:49 - 01:56 (00:07)
root pts/0 10.0.0.131 Mon Apr 15 01:44 - 01:49 (00:04)
root tty1 Mon Apr 15 01:38 -crash (17:26)
reboot system boot 2.6.18-194.el5 Mon Apr 15 01:36 (21+15:20)
reboot system boot 2.6.18-194.el5 Mon Apr 15 01:35 (21+15:22)
root tty1 Sat Apr 13 22:57 -crash (1+02:37)
reboot system boot 2.6.18-194.el5 Sat Apr 13 22:57 (22+18:00)
root tty1 Sat Apr 13 18:57 -crash (03:59)
reboot system boot 2.6.18-194.el5 Sat Apr 13 18:50 (22+22:07)
wtmp begins Sat Apr 13 18:50:022013
[root@yubing ~]#