命令：
# chkconfig- updates and queries runlevel information for system services
启动脚步的自动化管理
#进程管理命令
killall -term xproc
//此方法比killall -9 xproc要好。因为－9参数只释放当前进程的资源并终止它，而它的子进程都变成defunct状态，直到操作系统来销毁它们。
pgrep, pkill - look up or signal processes based on name and other attributes
＝＝＝＝＝例子：＝＝＝＝＝＝＝
[root@localhost ~]# pgrep -fl bash
2736 -bash
2796 -bash
skill, snice - send a signal or report process status
#用户管理的命令
chage - change use password expiry informatin
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
[root@localhost ~]# chage -l vic
Last password change : 3月 10, 2006
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
getfacl - 浏览指定文件或目录的ACL.
/etc/securetty 文件控制根用户从何处可以进行登录，如果/etc/securetty不存在，那么根用户就可以从任何地点进行登录；如果/etc/securetty存在但没有内容，根用户不可以从任何设备上登录，只能通过su或sudo进行根用户访问。
＃系统日志查看
/var/run/utmp /var/log/wtmp --登录记录文件，可以用who命令来查看。
/var/log 系统日志目录
lastb, last -- show listing of last logged in users
crypt - password and data encryption
crypt is the password encryption function. It is based on the Data Encryption Standard algorithm with variations intended (among other things) to discourage use of hardware implementations of a key search.
