sudo” 是Unix/Linux平台上的一个非常有用的工具，允许为非根用户赋予一些合理的“权利”，让他们执行一些只有根用户或特许用户才能完成的任务，从而减少根用户的登陆次数和管理时间同时也提高了系统安全性。
sudo的目的：为非根用户授予根用户的权限；
配置文件：/etc/sudoers
visudo命令编辑修改/etc/sudoers配置文件
visudo需要root权限
使用visudo命令打开sudo配置文件：（特别要注意的是别名一定要使用大写）
## 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## Groups of machines. You may prefer to use hostnames (perhaps 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，这时可以配置主机别名# Host_Alias FILESERVERS = fs1, fs2# Host_Alias MAILSERVERS = smtp, smtp2## User Aliases## 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/bin/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# Defaults specification## Disable "ssh hostname sudo", because it will show the password in clear. # You have to run "ssh -t hostname sudo ".# 一些环境变量的相关配置，具体情况可见man soduersDefaults requirettyDefaults env_resetDefaults env_keep = "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS"Defaults env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"Defaults env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"Defaults env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"Defaults env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin## 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.## 允许sys中户组中的用户使用NETWORKING等所有别名中配置的命令# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS## Allows people in group wheel to run all commands## 允许wheel用户组中的用户执行所有命令%wheel ALL=(ALL) ALL## 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## 允许users用户组中的用户关闭localhost这台服务器# %users localhost=/sbin/shutdown -h now## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)## 读取放置在/etc/sudoers.d/文件夹中的文件（此处的#不意味着这是一个声明）#includedir /etc/sudoers.d