Debian小问题：sudo不能使用

今天本打算用Debian做负载均衡测试，结果发现：
[quote]
zlex@localhost:~/Desktop$ sudo apt-get install tomcat6

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.

[sudo] password for zlex:
zlex is not in the sudoers file. This incident will be reported.[/quote]
sudo不能使用？！顿时无语！
Google搜索无数，发现：
[b]xxx is not in the sudoers file. This incident will be reported.[/b]
linux默认没有为当前用户开启sudo权限！
切换到root用户：

su

visudo

实际上是编辑[b]/etc/sudoers[/b]文件
将[b]zlex ALL=(ALL) ALL[/b]加入其中：
[quote]

# /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# See the man page for details on how to write a sudoers file.
#

Defaults env_reset

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root ALL=(ALL) ALL
zlex ALL=(ALL) ALL

# Uncomment to allow members of group sudo to not need a password
# (Note that later entries override this, so you might need to move
# it further down)
# %sudo ALL=NOPASSWD: ALL
[/quote]

再次执行命令：
[quote]zlex@localhost:~/Desktop$ sudo apt-get install tomcat6

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.

[sudo] password for zlex:
正在读取软件包列表... 完成
正在分析软件包的依赖关系树
正在读取状态信息... 完成
E: 无法找到软件包 tomcat6[/quote]

sudo终于可以用了！ :D


有时候我们只需要执行一条root权限的命令也要su到root，是不是有些不方便？这时可以用sudo代替。

补充：
使用[b]visudo命令[/b]，移动光标，找到[b]root ALL=(ALL) ALL[/b]一行，按a，进入append模式，输入[b]your_user_name ALL=(ALL)[/b]，然后按Esc，再输入:w保存文件，再:q退出。这样就把自己加入了sudo组，可以使用sudo命令了。

如果觉得在sudo的时候输入密码麻烦，把刚才的输入换成[b]your_user_name ALL=(ALL)NOPASSWD: ALL[/b]
:D

有的时候需要使用到一些服务，譬如使用service命令，启动一些服务，可以这样做：

vim .bashrc

[quote]# .bashrc

# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi

# User specific aliases and functions
export PATH=$PATH:/sbin;[/quote]
注意加入最后一行[b]export PATH=$PATH:/sbin;[/b]，就可以使用[b]/sbin/service[/b]了！