log-files – 了解用户登录Linux服务器的时间

在我的Debian Squeeze服务器中,所有用户登录和注销都记录在文件/var/log/auth.log中

Jan 28 07:11:06 xen8 sshd[29826]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 28 07:33:47 xen8 sshd[29826]: pam_unix(sshd:session): session closed for user root
Jan 28 09:45:58 xen8 sshd[14374]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 28 09:47:36 xen8 sshd[14374]: pam_unix(sshd:session): session closed for user root
Jan 29 07:37:48 xen8 sshd[24940]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 29 07:38:11 xen8 sshd[24940]: pam_unix(sshd:session): session closed for user root
Jan 29 08:35:13 xen8 sshd[25707]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 29 08:37:06 xen8 sshd[25707]: pam_unix(sshd:session): session closed for user root
Jan 29 16:59:39 xen8 sshd[30725]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 29 17:00:58 xen8 sshd[30725]: pam_unix(sshd:session): session closed for user root
Jan 29 17:11:17 xen8 sshd[30832]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jan 29 18:11:37 xen8 sshd[30832]: pam_unix(sshd:session): session closed for user root

通过进程ID,应该能够找到匹配的登录/注销,然后可以计算时间.但我的sed / awk技能非常有限,甚至可能还有现成的脚本/工具来完成这项任务？
是否有一种简单的方法来提取用户登录的时间？总计(每个文件),或者甚至是一些漂亮的图形？

解决方法

ac实用程序将为您提供有关用户登录的统计信息.例如,要查看名为user1的用户在系统上的秒/分钟/小时总数 –

ac -d user1

产量

Jan 22  total        4.19
 Jan 23  total        8.01
 Jan 24  total        7.84
 Jan 25  total        6.79
 Jan 28  total        7.37
 Jan 29  total        8.69
 Today   total        7.15