我通过 ssh 进入我的新 Linux 机器（无物理访问权限）并且拥有 root 凭据。但是，我无法运行 sudo 命令，因为之前以 root 身份登录的其他人在 sudoers 文件中出现了一些错误。
我曾经visudo将我的用户名添加到列表中，文件权限当前为：
-r--r----- 1 root root 3419 May 29 11:57 /etc/sudoers
我收到以下错误消息：
>>> /etc/sudoers: syntax error near line 82 <<<
sudo: parse error in /etc/sudoers near line 82
sudo: no valid sudoers sources found, quitting
请看一下并让我知道你们认为问题是什么。
我的 sudoers 文件的内容是：
## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
##
## 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.
##
## This file must be edited with the 'visudo' command.
## Host Aliases
## Groups of machines. You may prefer to use hostnames (perhap using
## wildcards for entire domains) or IP addresses instead.
# 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
# User_Alias ADMINS = jsmith, mikem
## Command Aliases
## These are groups of related commands...
## Networking
#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
#Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum
## Services
#Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig
## Updating the locate database
#Cmnd_Alias LOCATE = /usr/bin/updatedb
## Storage
#Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount
## Delegating permissions
#Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp
## Processes
#Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall
## Drivers
#Cmnd_Alias DRIVERS = /sbin/modprobe
# 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
#
# Refuse to run if unable to disable echo on the tty. This setting should also be
# changed in order to be able to use sudo without a tty. See requiretty above.
#
Defaults !visiblepw
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).
## 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
admin ALL-(ALL) ALL
shami 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
## Same thing without a password
# %wheel ALL=(ALL) NOPASSWD: ALL
## Allows members of the users group to mount and unmount the
## cdrom as root
# %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
答案1
一个简单的错字：
admin ALL-(ALL) ALL
应该：
admin ALL=(ALL) ALL