Linux shell sudo 命令
Linux shell sudo命令以系统管理者的身份执行指令,也就是,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。
sudo 命令语法格式
sudo -V
sudo -h
sudo -l
sudo -v
sudo -k
sudo -s
sudo -H
sudo [ -b ] [ -p prompt ] [ -u username/#uid] -s
sudo command
选项
- -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 命令使用
[yufei@locahost ~]$ sudo ls [sudo] password for yufei: yufei is not in the sudoers file. This incident will be reported.
指定用户执行命令
[yufei@localhost shell]$ sudo -u root ls -l total 16 -rw-r--r--. 1 root root 93 Sep 19 11:43 demo1.sh -rwxr-xr-x. 1 root root 219 Sep 19 11:43 demo2.sh -rw-r--r--. 1 root root 0 Sep 19 16:06 demo.cpp -rw-r--r--. 1 root root 122 Sep 19 11:43 demo.sh -rw-r--r--. 1 root root 0 Sep 19 16:06 main.c -rw-r--r--. 1 root root 113 Sep 21 00:14 w.sh
显示sudo设置
[yufei@localhost shell]$ 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 $HOME to the target user's home directory path_info: Allow some information gathering to give useful error messages fqdn: Require fully-qualified hostnames in the sudoers file insults: Insult the user when they enter an incorrect password requiretty: Only allow the user to run sudo if they have a tty env_editor: Visudo will honor the EDITOR environment variable rootpw: Prompt for root's password, not the users's runaspw: Prompt for the runas_default user's password, not the users's targetpw: Prompt for the target user's password, not the users's use_loginclass: Apply defaults in the target user's login class if there is one set_logname: Set the LOGNAME and USER environment variables stay_setuid: Only set the effective uid to the target user, not the real uid preserve_groups: Don't initialize the group vector to that of the target user loglinelen: Length at which to wrap log file lines (0 for no wrap) timestamp_timeout: Authentication timestamp timeout passwd_timeout: Password prompt timeout passwd_tries: Number of tries to enter a password umask: Umask to use or 0777 to use user's logfile: Path to log file mailerpath: Path to mail program mailerflags: Flags for mail program mailto: Address to send mail to mailfrom: Address to send mail from mailsub: Subject line for mail messages badpass_message: Incorrect password message timestampdir: Path to authentication timestamp dir timestampowner: Owner of the authentication timestamp dir exempt_group: Users in this group are exempt from password and PATH requirements passprompt: Default password prompt passprompt_override: If set, passprompt will override system prompt in all cases. ...
以 root 权限执行上一条命令
[yufei@localhost shell]$ sudo !! total 16 -rw-r--r--. 1 root root 93 Sep 19 11:43 demo1.sh -rwxr-xr-x. 1 root root 219 Sep 19 11:43 demo2.sh -rw-r--r--. 1 root root 0 Sep 19 16:06 demo.cpp -rw-r--r--. 1 root root 122 Sep 19 11:43 demo.sh -rw-r--r--. 1 root root 0 Sep 19 16:06 main.c -rw-r--r--. 1 root root 113 Sep 21 00:14 w.sh
以特定用户身份进行编辑文本
以 root 用户身份编辑 /data/www 下的 index.html
文件
[yufei@localhost shell]$ sudo -u root vi /data/www/cn_twle_www/index.html
列出目前的权限
[yufei@localhost ~]$ sudo -l
列出 sudo 的版本资讯
[yufei@localhost ~]$ sudo -V