今天准备培训环境的时候一不小心把/etc/sudoers给删掉了。。。
后来终于改好了，不过在这留个备份

## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
##该文件允许特定用户像root用户一样使用各种各样的命令，而不需要root用户的密码 
##
## Examples are provided at the bottom of the file for collections
## of related commands, which can then be delegated out to particular
## users or groups.
## 在文件的底部提供了很多相关命令的示例以供选择，这些示例都可以被特定用户或  
## ## 用户组所使用  
## This file must be edited with the 'visudo' command.
## 该文件必须使用"visudo"命令编辑
## Host Aliases
#主机别名
## Groups of machines. You may prefer to use hostnames (perhap using 
## wildcards for entire domains) or IP addresses instead.
## 对于一组服务器，你可能会更喜欢使用主机名（可能是全域名的通配符）
## 或IP地址代替，这时可以配置主机别名

# Host_Alias     FILESERVERS = fs1, fs2
# Host_Alias     MAILSERVERS = smtp, smtp2
## User Aliases
#用户别名
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname 
## rather than USERALIAS
## 这并不很常用，因为你可以通过使用组来代替一组用户的别名  
# User_Alias ADMINS = jsmith, mikem

## Command Aliases
## These are groups of related commands...
## 指定一系列相互关联的命令（当然可以是一个）的别名，通过赋予该别名sudo权限，  
## 可以通过sudo调用所有别名包含的命令，下面是一些示例

## Networking
#网络操作相关命令别名  
Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient,
 /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, 
 /sbin/mii-tool
## Installation and management of software
#软件安装管理相关命令别名  
Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum
## Services
#服务相关命令别名 
Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig
## Updating the locate database
#本地数据库升级命令别名  
Cmnd_Alias LOCATE = /usr/sbin/updatedb
## Storage
#磁盘操作相关命令别名
Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount
## Delegating permissions
#代理权限相关命令别名 
Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp
## Processes
#进程相关命令别名
Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall
## Drivers
#驱动命令别名
Cmnd_Alias DRIVERS = /sbin/modprobe
#环境变量的相关配置
# Defaults specification
#
# Disable "ssh hostname sudo <cmd>", because it will show the password in clear. 
#         You have to run "ssh -t hostname sudo <cmd>".
#
Defaults    requiretty
Defaults    env_reset
Defaults    env_keep = "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR \
                        LS_COLORS MAIL PS1 PS2 QTDIR USERNAME \
                        LANG LC_ADDRESS LC_CTYPE LC_COLLATE LC_IDENTIFICATION \
                        LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERIC \
                        LC_PAPER LC_TELEPHONE LC_TIME LC_ALL LANGUAGE LINGUAS \
                        _XKB_CHARSET XAUTHORITY"
## Next comes the main part: which users can run what software on
## which machines (the sudoers file can be shared between multiple
## systems).
## 下面是规则配置：什么用户在哪台服务器上可以执行哪些命令（sudoers文件可以在多个系统上共享）
## Syntax:
##语法
##      user    MACHINE=COMMANDS
##  用户 登录的主机=（可以变换的身份） 可以执行的命令  
##
## The COMMANDS section may have other options added to it.
## 命令部分可以附带一些其它的选项  
##
## Allow root to run any commands anywhere 
## 允许root用户执行任意路径下的任意命令 
root    ALL=(ALL)       ALL
## Allows members of the 'sys' group to run networking, software,
## service management apps and more.
# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS
## 允许sys中户组中的用户使用NETWORKING等所有别名中配置的命令

## Allows people in group wheel to run all commands
# %wheel        ALL=(ALL)       ALL
## 允许wheel用户组中的用户执行所有命令  
## Same thing without a password
## 允许wheel用户组中的用户在不输入该用户的密码的情况下使用所有命令
# %wheel        ALL=(ALL)       NOPASSWD: ALL
## Allows members of the users group to mount and unmount the
## cdrom as root
## 允许users用户组中的用户像root用户一样使用mount、unmount、chrom命令 
# %users  ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom
## Allows members of the users group to shutdown this system
# %users  localhost=/sbin/shutdown -h now
## 允许users用户组中的用户像root用户一样使用shutdown命令```