Sudo (日本語)

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概括 help replacing me
一般的な権限を与えるユーティリティの概要。
概要
Template:Access control overview (日本語)

sudo ("substitute user do") を使うことでシステム管理者は権限を委託できるようになり、root や他のユーザーとして複数の(もしくは全ての)コマンドを実行する能力を特定のユーザー(もしくはユーザーのグループ)に与えることができます。また sudo を使うとコマンドや引数の記録が残ります。[1]

原理

Sudo は root でコマンドを実行するためのものとして su (日本語) に代わるものです。su (日本語) が root シェルを起動してそれから全てのコマンドを root として実行できるようにするのに対し、sudo は一つのコマンドだけに特権を与えます。必要な時だけに root 特権を有効にするので、sudo を使うことにより打ち間違いや呼び出されたコマンドのバグによってシステムを破壊してしまう可能性を減らすことができます。 Sudo は他のユーザーとしてコマンドを実行するために使うこともできます; さらに、sudo は全てのコマンドとセキュリティ検査のアクセス失敗を記録します。

インストール

公式リポジトリから sudo パッケージをインストールしてください:

# pacman -S sudo

sudo を特権がないユーザーとして使い始めるには、正しく設定をする必要があります。設定セクションを読んで設定を行なって下さい。

使用方法

ユーザーはコマンドの前に sudo を付けることで、スーパーユーザー(もしくはその他の)特権がある状態でコマンドを実行できます。

例えば、pacman を root で使いたいなら:

$ sudo pacman -Syu

詳しくは sudo マニュアルを見て下さい。

設定

現在の設定を表示

sudo -ll を実行して現在の sudo 設定を表示してください。

visudo を使う

sudo の設定ファイルは /etc/sudoers です。このファイルはどんなときでも visudo コマンドを使って編集するべきです。visudosudoers ファイルをロックし、一時ファイルに編集内容を保存して、それを /etc/sudoers にコピーする前にファイルの構文をチェックします。

Warning: sudoers に構文エラーの危険性があるということは絶対避けなくてはいけません!どんなエラーでも sudo を使用不可能にしてしまいます。エラーを防ぐためにいつでも visudo を使って編集するようにしてください。

visudo のデフォルトエディタは vi です。他のエディタを指定しなかった場合、vi が使われます。使いたいエディタ (例: vim) を指定するには VISUAL か EDITOR 環境変数をセットしてください。次のコマンドを root で実行します:

# VISUAL="/usr/bin/vim -p -X" visudo

~/.bashrc ファイルに以下を追加することでシステム全体で vim を使い続けるように設定できます:

export VISUAL="/usr/bin/vim -p -X"

ただし既に動作しているシェルには export の効果はありません。

visudo でだけ同じエディタを選び続けたいのなら、以下を /etc/sudoers に追加してください (vim はお好きなエディタに変えてください):

# Reset environment by default
Defaults      env_reset
# Set default EDITOR to vim, and do not allow visudo to use EDITOR/VISUAL.
Defaults      editor="/usr/bin/vim -p -X", !env_editor

エントリの例

ユーザー USER_NAME が sudo を使った時に、完全な root 権限を与えたい場合は、次の行を加えて下さい:

USER_NAME   ALL=(ALL) ALL

マシンのホストネームが HOST_NAME のときだけ、ユーザー USER_NAME に他のユーザーとしてコマンドを実行する権限を与えるには:

USER_NAME   HOST_NAME=(ALL) ALL

wheel グループに追加されている全てのユーザーが sudo を使えるようにするには:

%wheel      ALL=(ALL) ALL

ユーザー USER_NAME にパスワードを尋ねるのを無効化するには:

Defaults:USER_NAME      !authenticate

ユーザー USER_NAME が ホスト HOST_NAME を使っているときだけ特定のコマンドに sudo を使えるようにするには:

USER_NAME HOST_NAME=/sbin/halt,/sbin/poweroff,/sbin/reboot,/usr/bin/pacman -Syu
Note: 後ろの行の設定が前の設定よりも優先されるので、細かくカスタマイズしたオプションはファイルの最後に置くべきです。特にユーザーがグループに含まれているときは上のような行は %wheel 行の後にすべきです。

ユーザー USER_NAME が ホスト HOST_NAME を使っているときだけ特定のコマンドに sudo をパスワードなしで使えるようにするには:

USER_NAME HOST_NAME= NOPASSWD: /sbin/halt,/sbin/poweroff,/sbin/reboot,/usr/bin/pacman -Syu

説明のついた sudoers のサンプルはここにあります。詳しくは sudoers マニュアルを見て下さい。

Sudoers デフォルトファイルパーミッション

sudoers ファイルの所有者とグループはゼロにしてください、つまり所有者が居てはいけません。ファイルパーミッションは 0440 に設定する必要があります。このパーミッションはデフォルトでセットされますが、パーミッションを変える事故を起こしてしまった場合、すぐにパーミッションを元に戻すか sudo を消して下さい。

# chown -c root:root /etc/sudoers
# chmod -c 0440 /etc/sudoers

パスワードキャッシュのタイムアウト

キャッシュされたパスワードの有効期間の前にデフォルトのタイムアウトを変えることができます。/etc/sudoers の timestamp_timeout でこれができます。単位は分です。 タイムアウトを20分に設定:

Defaults:USER_NAME timestamp_timeout=20
Tip: sudo が毎回パスワードをきくようにしたいのなら、タイムアウトを 0 に設定してください。パスワードのタイムアウトをなくしたいのなら、0 未満に設定してください。

Tips and tricks

ファイル例

この例は screen, tmux, ratpoison などのターミナルマルチプレクサを使っている人や、スクリプトや cron ジョブから sudo を使っている人に役立つと思われます。

/etc/sudoers
Cmnd_Alias WHEELER = /usr/sbin/lsof, /bin/nice, /bin/ps, /usr/bin/top, /usr/local/bin/nano, /bin/netstat, /usr/bin/locate, /usr/bin/find, /usr/bin/rsync
Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/nice, /usr/bin/ionice, /usr/bin/top, /usr/bin/kill, /usr/bin/killall, /usr/bin/ps, /usr/bin/pkill
Cmnd_Alias EDITS = /usr/bin/vim, /usr/bin/nano, /usr/bin/cat, /usr/bin/vi
Cmnd_Alias ARCHLINUX = /usr/sbin/gparted, /usr/bin/pacman, /usr/bin/pacman-color

root ALL = (ALL) ALL
USER_NAME ALL = (ALL) ALL, NOPASSWD: WHEELER, NOPASSWD: PROCESSES, NOPASSWD: ARCHLINUX, NOPASSWD: EDITS
 
Defaults !requiretty, !tty_tickets, !umask
Defaults visiblepw, path_info, insults, lecture=always
Defaults loglinelen = 0, logfile =/var/log/sudo.log, log_year, log_host, syslog=auth
Defaults mailto=webmaster@foobar.com, mail_badpass, mail_no_user, mail_no_perms
Defaults passwd_tries = 8, passwd_timeout = 1
Defaults env_reset, always_set_home, set_home, set_logname
Defaults !env_editor, editor="/usr/bin/vim:/usr/bin/vi:/usr/bin/nano"
Defaults timestamp_timeout=360
Defaults passprompt="Sudo invoked by [%u] on [%H] - Cmd run as %U - Password for user %p:"

Bash のタブ補完を有効にする

ユーザーが sudoers ファイルに追加された最初のうちは、デフォルトで、Template:Keypress 補完は動作しないようになっています。例えば、通常 John が入力する必要があるのはこれだけです:

$ fire<Template:Keypress>

シェルが彼のためにコマンドを補完してくれるでしょう:

$ firefox

しかしながら、John が sudoers ファイルに追加されると、同じように入力しても:

$ sudo fire<Template:Keypress>

シェルは何もしません。

sudo で Template:Keypress 補完を有効にするには、公式リポジトリから bash-completion パッケージをインストールして下さい。詳しくは bash#Auto-completion を見て下さい。

もしくは、以下を ~/.bashrc に追加して下さい:

complete -cf sudo

sudo を使って X11 アプリを実行

sudo が X11 のグラフィカルアプリケーションを実行できるようにするには visudo に以下を追加する必要があります:

Defaults env_keep += "HOME"

ターミナルごとの sudo を無効化

Warning: 以下を行うとすべてのプロセスがあなたの sudo セッションを使うようになります。

sudo のデフォルト設定では、新しいターミナルを開くたびにパスワードを入力する必要がありますが、これを鬱陶しく感じるなら tty_tickets を無効化して下さい:

Defaults !tty_tickets

環境変数 (Outdated?)

If you have a lot of environment variables, or you export your proxy settings via export http_proxy="...", when using sudo these variables do not get passed to the root account unless you run sudo with the -E option.

$ sudo -E pacman -Syu

Because of this you may wish to add an alias in ~/.bashrc:

alias sudo="sudo -E"

Another way of fixing this would be to add in /etc/sudoers:

Defaults !env_reset

If you want to just pass *_proxy variables, add the following:

Defaults env_keep += "ftp_proxy http_proxy https_proxy no_proxy"

root パスに /sbin と /usr/sbin を追加

管理コマンド (/sbin/usr/sbin 内のコマンド) をフルパスを使わずに sudo で実行したいなら、以下を /etc/sudoers に追加して下さい:

Defaults secure_path="/bin:/sbin:/usr/bin:/usr/sbin"

これで、

$ sudo /usr/sbin/command

$ sudo /sbin/command

などのコマンドを次で実行できるようになります:

$ sudo command

エイリアスを渡す

使っているエイリアスが多すぎて、sudo を使っている時にそれらを root アカウントに持ち越せないことに気づいたかもしれませんね。しかしながら、エイリアスを全て動作させる簡単な方法があります。以下を ~/.bashrc/etc/bash.bashrc に追加するだけです:

alias sudo='sudo '

Insults

間違ったパスワードが入力されたときに、デフォルトの "wrong password" メッセージの代わりに侮辱的なメッセージを表示するように sudo を設定できます。/etc/sudoers 内の Defaults 行を探して既存のオプションの後に "insults" を加えて下さい。以下のようになります:

#Defaults specification
Defaults insults

テストするために、sudo -K を入力して現在のセッションを終わらせもう一度 sudo にパスワードを尋ねさせてください。

root パスワード

/etc/sudoers の Defaults 行に "rootpw" を加えると sudo はユーザーのパスワードではなく root パスワードを尋ねるようになります:

Defaults timestamp_timeout=0,rootpw

root ログインを無効化

Warning: Arch Linux は root アカウントが無効化された状態でもうまく動くようには作られていません。このメソッドを使うと問題が起こるかもしれません。

sudo をインストール・設定したら、root ログインを無効化したくなりましたか。root がないと、攻撃者はユーザーのパスワードだけでなく sudoer として設定されたユーザー名もまず考えなくてはならなくなります。

Warning: root アカウントを無効にする前にユーザーが sudoer として正しく設定されているか確認して下さい!

アカウントをロックするには passwd を使います:

# passwd -l root

同じようなコマンドで root をアンロックできます。

$ sudo passwd -u root

もしくは、/etc/shadow を編集して root の暗号化されたパスワードを "!" で置き換えてください:

root:!:12345::::::

もう一度 root ログインを有効にするには:

$ sudo passwd root

kdesu

kdesu may be used under KDE to launch GUI applications with root privileges. It is possible that by default kdesu will try to use su even if the root account is disabled. Fortunately one can tell kdesu to use sudo instead of su. Create/edit the file ~/.kde4/share/config/kdesurc:

[super-user-command]
super-user-command=sudo

PolicyKit

When disabling the root account, it is necessary to change the PolicyKit configuration for local authorization to reflect that. The default is to ask for the root password, so that must be changed. With polkit-1, this can be achieved by editing /etc/polkit-1/localauthority.conf.d/50-localauthority.conf so that AdminIdentities=unix-user:0 is replaced with something else, depending on the system configuration. It can be a list of users and groups, for example:

AdminIdentities=unix-group:wheel

or

AdminIdentities=unix-user:me;unixuser:mom;unix-group:wheel

For more information, see man pklocalauthority.

NetworkManager

Even with the above PolicyKit configuration you still need to configure a policy for NetworkManager. This is documented on the NetworkManager page of this wiki.

トラブルシューティング

SSH TTY 問題

SSH does not allocate a tty by default when running a remote command. Without a tty, sudo cannot disable echo when prompting for a password. You can use ssh's -tt option to force it to allocate a tty. (use -tt twice).

The Defaults option requiretty only allows the user to run sudo if they have a tty.

# Disable "ssh hostname sudo <cmd>", because it will show the password in clear text. You have to run "ssh -t hostname sudo <cmd>".
#
#Defaults    requiretty

ユーザー特権を表示

You can find out what privileges a particular user has with the following command:

$ sudo -lU yourusename

Or view your own with:

$ sudo -l
Matching Defaults entries for yourusename on this host:
    loglinelen=0, logfile=/var/log/sudo.log, log_year, syslog=auth, mailto=sqpt.webmaster@gmail.com, mail_badpass, mail_no_user, mail_no_perms, env_reset, always_set_home, tty_tickets, lecture=always, pwfeedback, rootpw, set_home

User yourusename may run the following commands on this host:

    (ALL) ALL
    (ALL) NOPASSWD: /usr/sbin/lsof, /bin/nice, /bin/netstat, /usr/bin/su, /usr/bin/locate, /usr/bin/find, /usr/bin/rsync, /usr/bin/strace,
    (ALL) /bin/nice, /bin/kill, /usr/bin/nice, /usr/bin/ionice, /usr/bin/top, /usr/bin/kill, /usr/bin/killall, /usr/bin/ps, /usr/bin/pkill
    (ALL) /usr/sbin/gparted, /usr/bin/pacman
    (ALL) /usr/local/bin/synergyc, /usr/local/bin/synergys
    (ALL) /usr/bin/vim, /usr/bin/nano, /usr/bin/cat
    (root) NOPASSWD: /usr/local/bin/synergyc

Permissive Umask

Sudo will union the user's umask value with its own umask (which defaults to 0022). This prevents sudo from creating files with more open permissions than the user's umask allows. While this is a sane default if no custom umask is in use, this can lead to situations where a utility run by sudo may create files with different permissions than if run by root directly. If errors arise from this, sudo provides a means to fix the umask, even if the desired umask is more permissive than the umask that the user has specified. Adding this (using visudo) will override sudo's default behavior:

Defaults umask = 0022
Defaults umask_override

This sets sudo's umask to root's default umask (0022) and overrides the default behavior, always using the indicated umask regardless of what umask the user as set.


デフォルトスケルトン

At this link you can find a list of all the options available to use with the Defaults command in /etc/sudoers.

Tango-edit-clear.pngThis article or section needs language, wiki syntax or style improvements.Tango-edit-clear.png

Reason: the comments in the following block of code are truncated. (Discuss in Talk:Sudo (日本語)#)

The same list is reproduced right below in a format optimized for copying and pasting it in your sudoers files and then make changes.

#Defaults       always_set_home
# always_set_home: If enabled, sudo will set the HOME environment variable to the home directory of the target user (which is root unless the -u option is used).  This effectively means that the -H op
#     always_set_home is only effective for configurations where either env_reset is disabled or HOME is present in the env_keep list.  This flag is off by default.

#Defaults       authenticate
# authenticate: If set, users must authenticate themselves via a password (or other means of authentication) before they may run commands.  This default may be overridden via the PASSWD and NOPASSWD t

#Defaults       closefrom_override
# closefrom_override: If set, the user may use sudo's -C option which overrides the default starting point at which sudo begins closing open file descriptors.  This flag is off by default.

#Defaults       compress_io
# compress_io: If set, and sudo is configured to log a command's input or output, the I/O logs will be compressed using zlib.  This flag is on by default when sudo is compiled with zlib support.

#Defaults       env_editor
# env_editor: If set, visudo will use the value of the EDITOR or VISUAL environment variables before falling back on the default editor list.  Note that this may create a security hole as it allows th
#   separated list of editors in the editor variable.  visudo will then only use the EDITOR or VISUAL if they match a value specified in editor.  This flag is on by default.

#Defaults       env_reset
# env_reset: If set, sudo will run the command in a minimal environment containing the TERM, PATH, HOME, MAIL, SHELL, LOGNAME, USER, USERNAME and SUDO_* variables.  Any variables in the caller's envir
#   in the file specified by the env_file option (if any).  The default contents of the env_keep and env_check lists are displayed when sudo is run by root with the -V option.  If the secure_path opti
#   default.

#Defaults       fast_glob
# fast_glob: Normally, sudo uses the glob(3) function to do shell-style globbing when matching path names.  However, since it accesses the file system, glob(3) can take a long time to complete for som
#   (automounted).  The fast_glob option causes sudo to use the fnmatch(3) function, which does not access the file system to do its matching.  The disadvantage of fast_glob is that it is unable to ma
#   names that include globbing characters are used with the negation operator, '!', as such rules can be trivially bypassed.  As such, this option should not be used when sudoers contains rules that

#Defaults       fqdn
# fqdn: Set this flag if you want to put fully qualified host names in the sudoers file.  I.e., instead of myhost you would use myhost.mydomain.edu.  You may still use the short form if you wish (and
#   sudo unusable if DNS stops working (for example if the machine is not plugged into the network).  Also note that you must use the host's official name as DNS knows it.  That is, you may not use a
#     all aliases from DNS.  If your machine's host name (as returned by the hostname command) is already fully qualified you shouldn't need to set fqdn.  This flag is off by default.

#Defaults       ignore_dot
# ignore_dot: If set, sudo will ignore '.' or '' (current dir) in the PATH environment variable; the PATH itself is not modified.  This flag is off by default.

#Defaults       ignore_local_sudoers
# ignore_local_sudoers: If set via LDAP, parsing of /etc/sudoers will be skipped.  This is intended for Enterprises that wish to prevent the usage of local sudoers files so that only LDAP is used.  Th
#   present, /etc/sudoers does not even need to exist. Since this option tells sudo how to behave when no specific LDAP entries have been matched, this sudoOption is only meaningful for the cn=default

#Defaults       insults
# insults: If set, sudo will insult users when they enter an incorrect password.  This flag is off by default.

#Defaults       log_host
# log_host: If set, the host name will be logged in the (non-syslog) sudo log file.  This flag is off by default.

#Defaults       log_input
# log_input: If set, sudo will run the command in a pseudo tty and log all user input.  If the standard input is not connected to the user's tty, due to I/O redirection or because the command is part
#   Input is logged to the directory specified by the iolog_dir option (/var/log/sudo-io by default) using a unique session ID that is included in the normal sudo log line, prefixed with TSID=.  The i
#   Note that user input may contain sensitive information such as passwords (even if they are not echoed to the screen), which will be stored in the log file unencrypted.  In most cases, logging the

#Defaults       log_output
# log_output: If set, sudo will run the command in a pseudo tty and log all output that is sent to the screen, similar to the script(1) command.  If the standard output or standard error is not connec
#   is also captured and stored in separate log files.
#   Output is logged to the directory specified by the iolog_dir option (/var/log/sudo-io by default) using a unique session ID that is included in the normal sudo log line, prefixed with TSID=.  The
#   Output logs may be viewed with the sudoreplay(8) utility, which can also be used to list or search the available logs.

#Defaults       log_year
# log_year: If set, the four-digit year will be logged in the (non-syslog) sudo log file.  This flag is off by default.

#Defaults       long_otp_prompt
# long_otp_prompt: When validating with a One Time Password (OTP) scheme such as S/Key or OPIE, a two-line prompt is used to make it easier to cut and paste the challenge to a local window.  It's not

#Defaults       mail_always
# mail_always: Send mail to the mailto user every time a users runs sudo.  This flag is off by default.

#Defaults       mail_badpass
# mail_badpass: Send mail to the mailto user if the user running sudo does not enter the correct password.  This flag is off by default.

#Defaults       mail_no_host
# mail_no_host: If set, mail will be sent to the mailto user if the invoking user exists in the sudoers file, but is not allowed to run commands on the current host.  This flag is off by default.

#Defaults       mail_no_perms
# mail_no_perms: If set, mail will be sent to the mailto user if the invoking user is allowed to use sudo but the command they are trying is not listed in their sudoers file entry or is explicitly den

#Defaults       mail_no_user
# mail_no_user: If set, mail will be sent to the mailto user if the invoking user is not in the sudoers file.  This flag is on by default.

#Defaults       noexec
# noexec: If set, all commands run via sudo will behave as if the NOEXEC tag has been set, unless overridden by a EXEC tag.  See the description of NOEXEC and EXEC below as well as the "PREVENTING SHE

#Defaults       path_info
# path_info: Normally, sudo will tell the user when a command could not be found in their PATH environment variable.  Some sites may wish to disable this as it could be used to gather information on t
#   the executable is simply not in the user's PATH, sudo will tell the user that they are not allowed to run it, which can be confusing.  This flag is on by default.

#Defaults       passprompt_override
# passprompt_override: The password prompt specified by passprompt will normally only be used if the password prompt provided by systems such as PAM matches the string "Password:".  If passprompt_over

#Defaults       preserve_groups
# preserve_groups: By default, sudo will initialize the group vector to the list of groups the target user is in.  When preserve_groups is set, the user's existing group vector is left unaltered.  The
#   default.

#Defaults       pwfeedback
# pwfeedback: By default, sudo reads the password like most other Unix programs, by turning off echo until the user hits the return (or enter) key.  Some users become confused by this as it appears to
#   the user presses a key.  Note that this does have a security impact as an onlooker may be able to determine the length of the password being entered.  This flag is off by default.

#Defaults       requiretty
# requiretty: If set, sudo will only run when the user is logged in to a real tty.  When this flag is set, sudo can only be run from a login session and not via other means such as cron(8) or cgi-bin

#Defaults       root_sudo
# root_sudo: If set, root is allowed to run sudo too.  Disabling this prevents users from "chaining" sudo commands to get a root shell by doing something like "sudo sudo /bin/sh".  Note, however, that
#   real additional security; it exists purely for historical reasons.  This flag is on by default.

#Defaults       rootpw
# rootpw: If set, sudo will prompt for the root password instead of the password of the invoking user.  This flag is off by default.

#Defaults       runaspw
# runaspw: If set, sudo will prompt for the password of the user defined by the runas_default option (defaults to root) instead of the password of the invoking user.  This flag is off by default.

#Defaults       set_home
# set_home: If enabled and sudo is invoked with the -s option the HOME environment variable will be set to the home directory of the target user (which is root unless the -u option is used).  This eff
#   is enabled, so set_home is only effective for configurations where either env_reset is disabled or HOME is present in the env_keep list.  This flag is off by default.

#Defaults       set_logname
# set_logname: Normally, sudo will set the LOGNAME, USER and USERNAME environment variables to the name of the target user (usually root unless the -u option is given).  However, since some programs (
#   may be desirable to change this behavior.  This can be done by negating the set_logname option.  Note that if the env_reset option has not been disabled, entries in the env_keep list will override

#Defaults       set_utmp
# set_utmp: When enabled, sudo will create an entry in the utmp (or utmpx) file when a pseudo-tty is allocated.  A pseudo-tty is allocated by sudo when the log_input, log_output or use_pty flags are e
#   the tty, time, type and pid fields updated.  This flag is on by default.

#Defaults       setenv
# setenv: Allow the user to disable the env_reset option from the command line via the -E option.  Additionally, environment variables set via the command line are not subject to the restrictions impo
#   variables in this manner.  This flag is off by default.

#Defaults       shell_noargs
# shell_noargs: If set and sudo is invoked with no arguments it acts as if the -s option had been given.  That is, it runs a shell as root (the shell is determined by the SHELL environment variable if
#   is off by default.

#Defaults       stay_setuid
# stay_setuid: Normally, when sudo executes a command the real and effective UIDs are set to the target user (root by default).  This option changes that behavior such that the real UID is left as the
#   systems that disable some potentially dangerous functionality when a program is run setuid.  This option is only effective on systems with either the setreuid() or setresuid() function.  This flag

#Defaults       targetpw
# targetpw: If set, sudo will prompt for the password of the user specified by the -u option (defaults to root) instead of the password of the invoking user.  In addition, the timestamp file name will
#   passwd database as an argument to the -u option.  This flag is off by default.

#Defaults       tty_tickets
# tty_tickets: If set, users must authenticate on a per-tty basis.  With this flag enabled, sudo will use a file named for the tty the user is logged in on in the user's time stamp directory.  If disa

#Defaults       umask_override
# umask_override: If set, sudo will set the umask as specified by sudoers without modification.  This makes it possible to specify a more permissive umask in sudoers than the user's own umask and matc
#   user's umask and what is specified in sudoers.  This flag is off by default.

#Defaults       use_pty
# use_pty: If set, sudo will run the command in a pseudo-pty even if no I/O logging is being gone.  A malicious program run under sudo could conceivably fork a background process that retains to the u
#   that impossible.  This flag is off by default.

#Defaults       utmp_runas
# utmp_runas: If set, sudo will store the name of the runas user when updating the utmp (or utmpx) file.  By default, sudo stores the name of the invoking user.  This flag is off by default.

#Defaults       visiblepw
# visiblepw: By default, sudo will refuse to run if the user must enter a password but it is not possible to disable echo on the terminal.  If the visiblepw flag is set, sudo will prompt for a passwor
#   somehost sudo ls" since rsh(1) does not allocate a tty.  This flag is off by default.

#Defaults       closefrom
# closefrom: Before it executes a command, sudo will close all open file descriptors other than standard input, standard output and standard error (ie: file descriptors 0-2).  The closefrom option can

#Defaults       passwd_tries
# passwd_tries: The number of tries a user gets to enter his/her password before sudo logs the failure and exits.  The default is 3.

#Defaults       loglinelen
# loglinelen: Number of characters per line for the file log.  This value is used to decide when to wrap lines for nicer log files.  This has no effect on the syslog log file, only the file log.  The

#Defaults       passwd_timeout
# passwd_timeout: Number of minutes before the sudo password prompt times out, or 0 for no timeout.  The timeout may include a fractional component if minute granularity is insufficient, for example 2

#Defaults       timestamp_timeout
# timestamp_timeout: Number of minutes that can elapse before sudo will ask for a passwd again.  The timeout may include a fractional component if minute granularity is insufficient, for example 2.5.
#   timestamp will never expire.  This can be used to allow users to create or delete their own timestamps via sudo -v and sudo -k respectively.

#Defaults       umask
# umask: Umask to use when running the command.  Negate this option or set it to 0777 to preserve the user's umask.  The actual umask that is used will be the union of the user's umask and the value o
#   running a command.  Note on systems that use PAM, the default PAM configuration may specify its own umask which will override the value set in sudoers.

#Defaults       badpass_message
# badpass_message: Message that is displayed if a user enters an incorrect password.  The default is Sorry, try again. unless insults are enabled.

#Defaults       editor
# editor: A colon (':') separated list of editors allowed to be used with visudo.  visudo will choose the editor that matches the user's EDITOR environment variable if possible, or the first editor in

#Defaults       iolog_dir
# iolog_dir: The top-level directory to use when constructing the path name for the input/output log directory.  Only used if the log_input or log_output options are enabled or when the LOG_INPUT or L
#   directory.  The default is "/var/log/sudo-io".
#   The following percent (`%') escape sequences are supported:
#     %{seq} - expanded to a monotonically increasing base-36 sequence number, such as 0100A5, where every two digits are used to form a new directory, e.g. 01/00/A5
#     %{user} - expanded to the invoking user's login name
#     %{group} - expanded to the name of the invoking user's real group ID
#     %{runas_user} - expanded to the login name of the user the command will be run as (e.g. root)
#     %{runas_group} - expanded to the group name of the user the command will be run as (e.g. wheel)
#     %{hostname} - expanded to the local host name without the domain name
#     %{command} - expanded to the base name of the command being run
#   In addition, any escape sequences supported by the system's strftime() function will be expanded.
#   To include a literal `%' character, the string `%%' should be used.

#Defaults       iolog_file
# iolog_file: The path name, relative to iolog_dir, in which to store input/output logs when the log_input or log_output options are enabled or when the LOG_INPUT or LOG_OUTPUT tags are present for a
#   See the iolog_dir option above for a list of supported percent (`%') escape sequences.
#   In addition to the escape sequences, path names that end in six or more Xs will have the Xs replaced with a unique combination of digits and letters, similar to the mktemp() function.

#Defaults       mailsub
# mailsub: Subject of the mail sent to the mailto user. The escape %h will expand to the host name of the machine.  Default is *** SECURITY information for %h ***.

#Defaults       noexec_file
# noexec_file: This option is no longer supported.  The path to the noexec file should now be set in the /etc/sudo.conf file.

#Defaults       passprompt
# passprompt: The default prompt to use when asking for a password; can be overridden via the -p option or the SUDO_PROMPT environment variable.  The following percent (`%') escape sequences are suppo
#     %H  expanded to the local host name including the domain name (only if the machine's host name is fully qualified or the fqdn option is set)
#     %h  expanded to the local host name 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
#   The default value is Password:.

#Defaults       runas_default
# runas_default: The default user to run commands as if the -u option is not specified on the command line.  This defaults to root.

#Defaults       syslog_badpri
# syslog_badpri: Syslog priority to use when user authenticates unsuccessfully.  Defaults to alert.
#   The following syslog priorities are supported: alert, crit, debug, emerg, err, info, notice, and warning.

#Defaults       syslog_goodpri
# syslog_goodpri: Syslog priority to use when user authenticates successfully.  Defaults to notice.
#   See syslog_badpri for the list of supported syslog priorities.

#Defaults       sudoers_locale
# sudoers_locale: Locale to use when parsing the sudoers file, logging commands, and sending email.  Note that changing the locale may affect how sudoers is interpreted.  Defaults to "C".

#Defaults       timestampdir
# timestampdir: The directory in which sudo stores its timestamp files.  The default is /var/db/sudo.

#Defaults       timestampowner
# timestampowner: The owner of the timestamp directory and the timestamps stored therein.  The default is root.

#Defaults       env_file
# env_file: The env_file option specifies the fully qualified path to a file containing variables to be set in the environment of the program being run.  Entries in this file should either be of the f
#   quotes.  Variables in this file are subject to other sudo environment settings such as env_keep and env_check.

#Defaults       exempt_group
# exempt_group: Users in this group are exempt from password and PATH requirements.  The group name specified should not include a % prefix.  This is not set by default.

#Defaults       group_plugin
# group_plugin: A string containing a sudoers group plugin with optional arguments.  This can be used to implement support for the nonunix_group syntax described earlier.  The string should consist of
#   configuration arguments the plugin requires.  These arguments (if any) will be passed to the plugin's initialization function.  If arguments are present, the string must be enclosed in double quot
#   For example, given /etc/sudo-group, a group file in Unix group format, the sample group plugin can be used:
#   Defaults group_plugin="sample_group.so /etc/sudo-group"
#   For more information see sudo_plugin(5).

#Defaults       lecture
# lecture: This option controls when a short lecture will be printed along with the password prompt.  It has the following possible values:
#     always  Always lecture the user.
#     never   Never lecture the user.
#     once    Only lecture the user the first time they run sudo.
#   If no value is specified, a value of once is implied.  Negating the option results in a value of never being used.  The default value is once.

#Defaults       lecture_file
# lecture_file: Path to a file containing an alternate sudo lecture that will be used in place of the standard lecture if the named file exists.  By default, sudo uses a built-in lecture.

#Defaults       listpw
# listpw: This option controls when a password will be required when a user runs sudo with the -l option.  It has the following possible values:
#     all     All the user's sudoers entries for the current host must have the NOPASSWD flag set to avoid entering a password.
#     always  The user must always enter a password to use the -l option.
#     any     At least one of the user's sudoers entries for the current host must have the NOPASSWD flag set to avoid entering a password.
#     never   The user need never enter a password to use the -l option.
#   If no value is specified, a value of any is implied.  Negating the option results in a value of never being used.  The default value is any.

#Defaults       logfile
# logfile: Path to the sudo log file (not the syslog log file).  Setting a path turns on logging to a file; negating this option turns it off.  By default, sudo logs via syslog.

#Defaults       mailerflags
# mailerflags: Flags to use when invoking mailer. Defaults to -t.

#Defaults       mailerpath
# mailerpath: Path to mail program used to send warning mail.  Defaults to the path to sendmail found at configure time.

#Defaults       mailfrom
# mailfrom: Address to use for the "from" address when sending warning and error mail.  The address should be enclosed in double quotes (") to protect against sudo interpreting the @ sign.  Defaults t

#Defaults       mailto
# mailto: Address to send warning and error mail to.  The address should be enclosed in double quotes (") to protect against sudo interpreting the @ sign.  Defaults to root.

#Defaults       secure_path
# secure_path: Path used for every command run from sudo.  If you don't trust the people running sudo to have a sane PATH environment variable you may want to use this.  Another use is if you want to
#   option are not affected by secure_path.  This option is not set by default.

#Defaults       syslog
# syslog: Syslog facility if syslog is being used for logging (negate to disable syslog logging).  Defaults to auth.
#   The following syslog facilities are supported: authpriv (if your OS supports it), auth, daemon, user, local0, local1, local2, local3, local4, local5, local6, and local7.

#Defaults       verifypw
# verifypw: This option controls when a password will be required when a user runs sudo with the -v option.  It has the following possible values:
#     all     All the user's sudoers entries for the current host must have the NOPASSWD flag set to avoid entering a password.
#     always  The user must always enter a password to use the -v option.
#     any     At least one of the user's sudoers entries for the current host must have the NOPASSWD flag set to avoid entering a password.
#     never   The user need never enter a password to use the -v option.
#   If no value is specified, a value of all is implied.  Negating the option results in a value of never being used.  The default value is all.

#Defaults       env_check
# env_check: Environment variables to be removed from the user's environment if the variable's value contains % or / characters.  This can be used to guard against printf-style format vulnerabilities
#   value without double-quotes.  The list can be replaced, added to, deleted from, or disabled by using the =, +=, -=, and ! operators respectively.  Regardless of whether the env_reset option is ena
#   they pass the aforementioned check.  The default list of environment variables to check is displayed when sudo is run by root with the -V option.

#Defaults       env_delete
# env_delete: Environment variables to be removed from the user's environment when the env_reset option is not in effect.  The argument may be a double-quoted, space-separated list or a single value w
#   +=, -=, and ! operators respectively.  The default list of environment variables to remove is displayed when sudo is run by root with the -V option.  Note that many operating systems will remove p

#Defaults       env_keep
# env_keep: Environment variables to be preserved in the user's environment when the env_reset option is in effect.  This allows fine-grained control over the environment sudo-spawned processes will r
#   quotes.  The list can be replaced, added to, deleted from, or disabled by using the =, +=, -=, and ! operators respectively.  The default list of variables to keep is displayed when sudo is run by