Linux sudo命令详解 Linux sudo命令怎么用

Linux sudo命令以系统管理者的身份执行指令，也就是说，经由 sudo 所执行的指令就好像是 root 亲自执行。

使用权限：在 /etc/sudoers 中有出现的使用者。

语法

sudo -V

sudo -h

sudo -l

sudo -v

sudo -k

sudo -s

sudo -H

sudo [ -b ] [ -p prompt ] [ -u username/#uid] -s

sudo command

参数说明：

• -V 显示版本编号
• -h 会显示版本编号及指令的使用方式说明
• -l 显示出自己（执行 sudo 的使用者）的权限
• -v 因为 sudo 在第一次执行时或是在 N 分钟内没有执行（N 预设为五）会问密码，这个参数是重新做一次确认，如果超过 N 分钟，也会问密码
• -k 将会强迫使用者在下一次执行 sudo 时问密码（不论有没有超过 N 分钟）
• -b 将要执行的指令放在背景执行
• -p prompt 可以更改问密码的提示语，其中 %u 会代换为使用者的帐号名称， %h 会显示主机名称
• -u username/#uid 不加此参数，代表要以 root 的身份执行指令，而加了此参数，可以以 username 的身份执行指令（#uid 为该 username 的使用者号码）
• -s 执行环境变数中的 SHELL 所指定的 shell ，或是 /etc/passwd 里所指定的 shell
• -H 将环境变数中的 HOME （家目录）指定为要变更身份的使用者家目录（如不加 -u 参数就是系统管理者 root ）
• command 要以系统管理者身份（或以 -u 更改为其他人）执行的指令

实例

sudo命令使用

$ sudo ls

[sudo] password for hnlinux:

hnlinux is not in the sudoers file. This incident will be reported.

指定用户执行命令

# sudo -u userb ls -l

显示sudo设置

$ sudo -L //显示sudo设置

Available options in a sudoers ``Defaults'' line:

syslog: Syslog facility if syslog is being used for logging

syslog_goodpri: Syslog priority to use when user authenticates successfully

syslog_badpri: Syslog priority to use when user authenticates unsuccessfully

long_otp_prompt: Put OTP prompt on its own line

ignore_dot: Ignore '.' in $PATH

mail_always: Always send mail when sudo is run

mail_badpass: Send mail if user authentication fails

mail_no_user: Send mail if the user is not in sudoers

mail_no_host: Send mail if the user is not in sudoers for this host

mail_no_perms: Send mail if the user is not allowed to run a command

tty_tickets: Use a separate timestamp for each user/tty combo

lecture: Lecture user the first time they run sudo

lecture_file: File containing the sudo lecture

authenticate: Require users to authenticate by default

root_sudo: Root may run sudo

log_host: Log the hostname in the (non-syslog) log file

log_year: Log the year in the (non-syslog) log file

shell_noargs: If sudo is invoked with no arguments, start a shell

set_home: Set $HOME to the target user when starting a shell with -s

always_set_home: Always set $HOME to the target user's home directory

path_info: Allow some information gathering to give useful error messages

fqdn: Require fully-qualified hostnames in the sudoers file

insults: Insult the user when they enter an incorrect password

requiretty: Only allow the user to run sudo if they have a tty

env_editor: Visudo will honor the EDITOR environment variable

rootpw: Prompt for root's password, not the users's

runaspw: Prompt for the runas_default user's password, not the users's

targetpw: Prompt for the target user's password, not the users's

use_loginclass: Apply defaults in the target user's login class if there is one

set_logname: Set the LOGNAME and USER environment variables

stay_setuid: Only set the effective uid to the target user, not the real uid

preserve_groups: Don't initialize the group vector to that of the target user

loglinelen: Length at which to wrap log file lines (0 for no wrap)

timestamp_timeout: Authentication timestamp timeout

passwd_timeout: Password prompt timeout

passwd_tries: Number of tries to enter a password

umask: Umask to use or 0777 to use user's

logfile: Path to log file

mailerpath: Path to mail program

mailerflags: Flags for mail program

mailto: Address to send mail to

mailfrom: Address to send mail from

mailsub: Subject line for mail messages

badpass_message: Incorrect password message

timestampdir: Path to authentication timestamp dir

timestampowner: Owner of the authentication timestamp dir

exempt_group: Users in this group are exempt from password and PATH requirements

passprompt: Default password prompt

passprompt_override: If set, passprompt will override system prompt in all cases.

runas_default: Default user to run commands as

secure_path: Value to override user's $PATH with

editor: Path to the editor for use by visudo

listpw: When to require a password for 'list' pseudocommand

verifypw: When to require a password for 'verify' pseudocommand

noexec: Preload the dummy exec functions contained in 'noexec_file'

noexec_file: File containing dummy exec functions

ignore_local_sudoers: If LDAP directory is up, do we ignore local sudoers file

closefrom: File descriptors >= %d will be closed before executing a command

closefrom_override: If set, users may override the value of `closefrom' with the -C option

setenv: Allow users to set arbitrary environment variables

env_reset: Reset the environment to a default set of variables

env_check: Environment variables to check for sanity

env_delete: Environment variables to remove

env_keep: Environment variables to preserve

role: SELinux role to use in the new security context

type: SELinux type to use in the new security context

askpass: Path to the askpass helper program

env_file: Path to the sudo-specific environment file

sudoers_locale: Locale to use while parsing sudoers

visiblepw: Allow sudo to prompt for a password even if it would be visisble

pwfeedback: Provide visual feedback at the password prompt when there is user input

fast_glob: Use faster globbing that is less accurate but does not access the filesystem

umask_override: The umask specified in sudoers will override the user's, even if it is

more permissive

以root权限执行上一条命令

$ sudo !!

以特定用户身份进行编辑文本

$ sudo -u uggc vi ~www/index.html

//以 uggc 用户身份编辑 home 目录下www目录中的 index.html 文件

列出目前的权限

sudo -l

列出 sudo 的版本资讯

sudo -V