Linux操作系统下Sudo命令的使用方法?

Posted 2023-02-19

Linux操作系统下Sudo命令的使用方法是什么~？？

名称：sudo
　　使用权限：在 /etc/sudoers 中有出现的使用者
　　使用方式：sudo -V
　　sudo -h
　　sudo -l
　　sudo -v
　　sudo -k
　　sudo -s
　　sudo -H
　　sudo [ -b ] [ -p prompt ] [ -u username/#uid] -s
　　sudo command
　　说明：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
　　参数：
　　-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
　　范例：
　　sudo -l 列出目前的权限
　　sudo -V 列出 sudo 的版本资讯 参考技术A 建议：
在Linux系统下，右键打开终端后，可以输入"man sudo"或者"info sudo"查询，因为使用方法实在是太多，可以摘要如下，其他可以自己查看。
NAME
sudo, sudoedit - execute a command as another user

SYNOPSIS
sudo -h | -K | -k | -L | -l | -V | -v

sudo [-bEHPS] [-p prompt] [-u username|#uid] [VAR=value]
-i | -s | command

sudoedit [-S] [-p prompt] [-u username|#uid] file ...

OPTIONS
sudo accepts the following command line options:

-b The -b (background) option tells sudo to run the given command in
the background. Note that if you use the -b option you cannot use
shell job control to manipulate the process.

-E The -E (preserve environment) option will override the env_reset
option in sudoers(5)). It is only available when either the
matching command has the SETENV tag or the setenv option is set in
sudoers(5).

-e The -e (edit) option indicates that, instead of running a command,
the user wishes to edit one or more files. In lieu of a command,
the string "sudoedit" is used when consulting the sudoers file. If
the user is authorized by sudoers the following steps are taken:

1. Temporary copies are made of the files to be edited with the
owner set to the invoking user.

2. The editor specified by the VISUAL or EDITOR environment vari-
ables is run to edit the temporary files. If neither VISUAL
nor EDITOR are set, the program listed in the editor sudoers
variable is used.

3. If they have been modified, the temporary files are copied back
to their original location and the temporary versions are
removed.

If the specified file does not exist, it will be created. Note
that unlike most commands run by sudo, the editor is run with the
invoking user's environment unmodified. If, for some reason, sudo
is unable to update a file with its edited version, the user will
receive a warning and the edited copy will remain in a temporary
file.

-H The -H (HOME) option sets the HOME environment variable to the
homedir of the target user (root by default) as specified in
passwd(5). By default, sudo does not modify HOME (see set_home and
always_set_home in sudoers(5)).

-h The -h (help) option causes sudo to print a usage message and exit.

-i The -i (simulate initial login) option runs the shell specified in
the passwd(5) entry of the user that the command is being run as.
The command name argument given to the shell begins with a '-' to
tell the shell to run as a login shell. sudo attempts to change to
that user's home directory before running the shell. It also ini-
tializes the environment, leaving TERM unchanged, setting HOME,
SHELL, USER, LOGNAME, and PATH, and unsetting all other environment
variables. Note that because the shell to use is determined before
the sudoers file is parsed, a runas_default setting in sudoers will
specify the user to run the shell as but will not affect which
shell is actually run.

-K The -K (sure kill) option is like -k except that it removes the
user's timestamp entirely. Like -k, this option does not require a
password.

-k The -k (kill) option to sudo invalidates the user's timestamp by
setting the time on it to the Epoch. The next time sudo is run a
password will be required. This option does not require a password
and was added to allow a user to revoke sudo permissions from a
.logout file.

-L The -L (list defaults) option will list out the parameters that may
be set in a Defaults line along with a short description for each.
This option is useful in conjunction with grep(1).

-l The -l (list) option will list out the allowed (and forbidden) com-
mands for the invoking user on the current host.

-P The -P (preserve group vector) option causes sudo to preserve the
invoking user's group vector unaltered. By default, sudo will ini-
tialize the group vector to the list of groups the target user is
in. The real and effective group IDs, however, are still set to
match the target user.

-p The -p (prompt) option allows you to override the default password
prompt and use a custom one. The following percent ('%') escapes
are supported:

%H expanded to the local hostname including the domain name (on if
the machine's hostname is fully qualified or the fqdn sudoers
option is set)

%h expanded to the local hostname without the domain name

%p expanded to the user whose password is being asked for
(respects the rootpw, targetpw and runaspw flags in sudoers)

%U expanded to the login name of the user the command will be run
as (defaults to root)

%u expanded to the invoking user's login name

%% two consecutive % characters are collapsed into a single %
character

-S The -S (stdin) option causes sudo to read the password from the
standard input instead of the terminal device.

-s The -s (shell) option runs the shell specified by the SHELL envi-
ronment variable if it is set or the shell as specified in
passwd(5).

-u The -u (user) option causes sudo to run the specified command as a
user other than root. To specify a uid instead of a username, use
#uid. When running commands as a uid, many shells require that the
'#' be escaped with a backslash ('\'). Note that if the targetpw
Defaults option is set (see sudoers(5)) it is not possible to run
commands with a uid not listed in the password database.
-V The -V (version) option causes sudo to print the version number and
exit. If the invoking user is already root the -V option will
print out a list of the defaults sudo was compiled with as well as
the machine's local network addresses.

-v If given the -v (validate) option, sudo will update the user's
timestamp, prompting for the user's password if necessary. This
extends the sudo timeout for another 5 minutes (or whatever the
timeout is set to in sudoers) but does not run a command.

-- The -- flag indicates that sudo should stop processing command line
arguments. It is most useful in conjunction with the -s flag.

Environment variables to be set for the command may also be passed on
the command line in the form of VAR=value, e.g.
LD_LIBRARY_PATH=/usr/local/pkg/lib. Variables passed on the command
line are subject to the same restrictions as normal environment vari-
ables with one important exception. If the setenv option is set in
sudoers, the command to be run has the SETENV tag set or the command
matched is ALL, the user may set variables that would overwise be for-
bidden. See sudoers(5) for more information.

参考资料：RHEL 5 "man sudo"说明

参考技术B sudo命令格式如下：

　　sudo -K | -L | -V | -h | -k | -l | -vsudo [-HPSb] [-a auth_type] [-c
　　class|-] [-p prompt] [-u username|#uid] -e file [...] | -i | -s | command

　　下面我们再来看一下sudo其它常用的一些参数：

　　选项 含义 作用
　　sudo -h Help 列出使用方法，退出。
　　sudo -V Version 显示版本信息，并退出。
　　sudo -l List 列出当前用户可以执行的命令。只有在sudoers里的用户才能使用该选项。
　　sudo -u username|#uid User 以指定用户的身份执行命令。后面的用户是除root以外的，可以是用户名，也可以是#uid。

　　sudo -k Kill 清除“入场卷”上的时间，下次再使用sudo时要再输入密码。

　　sudo -K Sure kill 与-k类似，但是它还要撕毁“入场卷”，也就是删除时间戳文件。

　　sudo -b command Background 在后台执行指定的命令。
　　sudo -p prompt command Prompt 可以更改询问密码的提示语，其中%u会代换为使用者帐号名称，%h会显示主机名称。非常人性化的设计。
　　sudo -e file Edit 不是执行命令，而是修改文件，相当于命令sudoedit 参考技术C 查看、修改或者执行某些命令需要root用户的权限，如果不想直接切换到root用户，就可以使用sudo命令。sudo命令用于针对单个命令授予临时权限。sudo仅在需要时授予用户权限，减少了用户因为错误执行命令损坏系统的可能性。
使用方法是在原有命令之前加上sudo+空格。
用法示例：以root用户的身份修改主机名为zhidao
$ sudo hostname zhidao