RHEL 6.4中解决xx用户不在sudoers列表，此事将被报告的问题

1.使用sudo service iptables status命令时报告没有权限：

[tansheng@localhost ~]$ sudo service iptables status
[sudo] password for tansheng:
tansheng 不在 sudoers 文件中。此事将被报告。
[tansheng@localhost ~]$ 

2.从网上搜索得知需要修改/etc/sudoers文件，但是该文件对root用户都只有只读权限，后来查到linux已经预留了专门的命令visudo来编辑该文件：

[tansheng@localhost ~]$ visudo
visudo：/etc/sudoers：权限不够
visudo：/etc/sudoers：权限不够
[tansheng@localhost ~]$ su - root
密码：
-bash: EDITOR: command not found
[root@localhost ~]# visudo
visudo：/etc/sudoers.tmp 未更改
[root@localhost ~]# 

3.在切换到root用户下，用visudo编辑/etc/sudoers文件，加入一行：tansheng     ALL=(ALL)     ALL

## Syntax:
##
##      user    MACHINE=COMMANDS
##
## The COMMANDS section may have other options added to it.
##
## Allow root to run any commands anywhere
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

## Allows people in group wheel to run all commands
# %wheel        ALL=(ALL)       ALL
tansheng       ALL=(ALL)    ALL

## Same thing without a password
# %wheel        ALL=(ALL)       NOPASSWD: ALL

## Allows members of the users group to mount and unmount the
## cdrom as root

4.一切ok,tansheng用户可以使用sudo命令了

[root@localhost ~]# su - tansheng
[tansheng@localhost ~]$ sudo service sshd status
[sudo] password for tansheng:
openssh-daemon (pid  ) 正在运行...
[tansheng@localhost ~]$