Linux sudo命令
Linux sudo命令以系統管理者的身份執行指令，也就是說，經由sudo 所執行的指令就好像是root 親自執行。
使用權限：在/etc/sudoers 中有出現的使用者。
語法
sudo -V
sudo -h
sudo -l
sudo -v
sudo -k
sudo -s
sudo -H
sudo [ -b ] [ -p prompt ] [ -u username/#uid] -s
sudo command
參數說明 ：
- -V 顯示版本編號
- -h 會顯示版本編號及指令的使用方式說明
- -l 顯示出自己（執行sudo 的使用者）的權限
- -v 因為sudo 在第一次執行時或是在N 分鐘內沒有執行（N 預設為五）會問密碼，這個參數是重新做一次確認，如果超過N 分鐘，也會問密碼
- -k 將會強迫使用者在下一次執行sudo 時問密碼（不論有沒有超過N 分鐘）
- -b 將要執行的指令放在背景執行
- -p prompt 可以更改問密碼的提示語，其中%u 會代換為使用者的帳號名稱， %h 會顯示主機名稱
- -u username/#uid 不加此參數，代表要以root 的身份執行指令，而加了此參數，可以以username 的身份執行指令（#uid 為該username 的使用者號碼）
- -s 執行環境變數中的SHELL 所指定的shell ，或是/etc/passwd 裡所指定的shell
- -H 將環境變數中的HOME （家目錄）指定為要變更身份的使用者家目錄（如不加-u 參數就是系統管理者root ）
- command 要以系統管理者身份（或以-u 更改為其他人）執行的指令
實例
sudo命令使用
$ sudo ls [sudo] password for hnlinux: hnlinux is not in the sudoers file. This incident will be reported.
指定用戶執行命令
# sudo -u userb ls -l
顯示sudo設置
$ 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權限執行上一條命令
$ sudo !!
以特定用戶身份進行編輯文本
$ 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
列出目前的權限
sudo -l
列出sudo 的版本資訊
sudo -V