visudo — edit the sudoers file

       Many people have worked on sudo over the years; this version consists of code written primarily by:

             Todd C. Miller

       See the CONTRIBUTORS.md file in the sudo distribution  (https://www.sudo.ws/about/contributors/)  for  an
       exhaustive list of people who have contributed to sudo.

       If you believe you have found a bug in visudo, you can either file a bug report in the sudo bug database,
       https://bugzilla.sudo.ws/, or open an issue at https://github.com/sudo-project/sudo/issues.  If you would
       prefer   to   use   email,   messages   may   be    sent    to    the    sudo-workers    mailing    list,
       https://www.sudo.ws/mailman/listinfo/sudo-workers (public) or <sudo@sudo.ws> (private).

       Please  not  report  security  vulnerabilities  through  public GitHub issues, Bugzilla or mailing lists.
       Instead, report them via email to <Todd.Miller@sudo.ws>.  You may encrypt your message with  PGP  if  you
       would like, using the key found at https://www.sudo.ws/dist/PGPKEYS.

       There  is  no  easy  way  to prevent a user from gaining a root shell if the editor used by visudo allows
       shell escapes.

visudo  edits  the  sudoers  file in a safe fashion, analogous to vipw(8).  visudo locks the sudoers file
       against multiple simultaneous edits, performs basic validity checks, and checks for syntax errors  before
       installing  the edited file.  If the sudoers file is currently being edited you will receive a message to
       try again later.

       If the sudoers file does not exist, it will be created unless the editor exits  without  writing  to  the
       file.

       visudo  parses  the  sudoers file after editing and will not save the changes if there is a syntax error.
       Upon finding an error, visudo will print a message stating the line number(s) where  the  error  occurred
       and  the  user  will receive the “What now?” prompt.  At this point the user may enter ‘e’ to re-edit the
       sudoers file, ‘x’ to exit without saving the changes, or ‘Q’ to quit and save changes.   The  ‘Q’  option
       should  be used with extreme caution because if visudo believes there to be a syntax error, so will sudo.
       If ‘e’ is typed to edit the sudoers file after a syntax error has  been  detected,  the  cursor  will  be
       placed on the line where the error occurred (if the editor supports this feature).

       There are two sudoers settings that determine which editor visudo will run.

       editor      A  colon  (‘:’) separated list of editors allowed to be used with visudo.  visudo will choose
                   the editor that matches the user's SUDO_EDITOR, VISUAL, or  EDITOR  environment  variable  if
                   possible,  or  the  first  editor  in  the list that exists and is executable.  sudo does not
                   preserve the SUDO_EDITOR, VISUAL, or EDITOR environment variables unless they are present  in
                   the  env_keep  list  or  the  env_reset  option is disabled in the sudoers file.  The default
                   editor path is /usr/bin/editor which can  be  set  at  compile  time  via  the  --with-editor
                   configure option.

       env_editor  If set, visudo will use the value of the SUDO_EDITOR, VISUAL, or EDITOR environment variables
                   before  falling  back  on  the  default editor list.  visudo is typically run as root so this
                   option may allow a user with visudo privileges to run  arbitrary  commands  as  root  without
                   logging.   An  alternative is to place a colon-separated list of “safe” editors in the editor
                   variable.  visudo will then only use SUDO_EDITOR, VISUAL, or EDITOR if  they  match  a  value
                   specified  in  editor.   If  the  env_reset  flag is enabled, the SUDO_EDITOR, VISUAL, and/or
                   EDITOR environment variables must be present in the env_keep list for the env_editor flag  to
                   function  when  visudo  is  invoked  via  sudo.  The default value is on, which can be set at
                   compile time via the --with-env-editor configure option.

       The options are as follows:

       -c, --check
               Enable check-only mode.  The existing sudoers file (and any other  files  it  includes)  will  be
               checked  for  syntax errors.  If the path to the sudoers file was not specified, visudo will also
               check the file ownership and permissions (see the -O and -P options).  A message will be  printed
               to  the  standard output describing the status of sudoers unless the -q option was specified.  If
               the check completes successfully,  visudo  will  exit  with  a  value  of  0.   If  an  error  is
               encountered, visudo will exit with a value of 1.

       -fsudoers, --file=sudoers
               Specify  an  alternate  sudoers file location, see below.  As of version 1.8.27, the sudoers path
               can be specified without using the -f option.

       -h, --help
               Display a short help message to the standard output and exit.

       -I, --no-includes
               Disable the editing of include files unless there is a pre-existing syntax  error.   By  default,
               visudo  will  edit  the  main  sudoers  file  and  any  files  included  via @include or #include
               directives.  Files included via @includedir or #includedir are never edited unless they contain a
               syntax error.

       -O, --owner
               Enforce the default ownership (user and group) of the sudoers file.  In edit mode, the  owner  of
               the edited file will be set to the default.  In check mode (-c), an error will be reported if the
               owner is incorrect.  This option is enabled by default if the sudoers file was not specified.

       -P, --perms
               Enforce the default permissions (mode) of the sudoers file.  In edit mode, the permissions of the
               edited  file  will  be  set to the default.  In check mode (-c), an error will be reported if the
               file permissions are incorrect.  This option is enabled by default if the sudoers  file  was  not
               specified.

       -q, --quiet
               Enable  quiet  mode.   In  this mode details about syntax errors are not printed.  This option is
               only useful when combined with the -c option.

       -s, --strict
               Enable strict checking of the sudoers file.  If an alias is referenced but not  actually  defined
               or if there is a cycle in an alias, visudo will consider this a syntax error.  It is not possible
               to  differentiate between an alias and a host name or user name that consists solely of uppercase
               letters, digits, and the underscore (‘_’) character.

       -V, --version
               Print the visudo and sudoers grammar versions and exit.

       A sudoers file may be specified instead of the default, /etc/sudoers.  The temporary  file  used  is  the
       specified  sudoers file with “.tmp” appended to it.  In check-only mode only, ‘-’ may be used to indicate
       that sudoers will be read from the standard input.  Because the policy is evaluated in its  entirety,  it
       is not sufficient to check an individual sudoers include file for syntax errors.

   Debuggingandsudoerspluginargumentsvisudo  versions  1.8.4  and  higher  support a flexible debugging framework that is configured via Debug
       lines in the sudo.conf(5) file.

       Starting with sudo 1.8.12, visudo will also parse the arguments to the sudoers  plugin  to  override  the
       default  sudoers  path  name,  user-ID,  group-ID, and file mode.  These arguments, if present, should be
       listed after the path to the plugin (i.e., after  sudoers.so).   Multiple  arguments  may  be  specified,
       separated by white space.  For example:

           Plugin sudoers_policy sudoers.so sudoers_mode=0400

       The following arguments are supported:

       sudoers_file=pathname
             The sudoers_file argument can be used to override the default path to the sudoers file.

       sudoers_uid=user-ID
             The  sudoers_uid argument can be used to override the default owner of the sudoers file.  It should
             be specified as a numeric user-ID.

       sudoers_gid=group-ID
             The sudoers_gid argument can be used to override the default group of the sudoers file.  It must be
             specified as a numeric group-ID (not a group name).

       sudoers_mode=mode
             The sudoers_mode argument can be used to override the default file mode for the sudoers  file.   It
             should be specified as an octal value.

       For more information on configuring sudo.conf(5), refer to its manual.

       In addition to reporting sudoers syntax errors, visudo may produce the following messages:

       sudoersfilebusy,tryagainlater.
             Someone else is currently editing the sudoers file.

       /etc/sudoers:Permissiondenied
             You didn't run visudo as root.

       youdonotexistinthepasswddatabase
             Your user-ID does not appear in the system passwd database.

       Warning:{User,Runas,Host,Cmnd}_Aliasreferencedbutnotdefined
             Either you are trying to use an undeclared {User,Runas,Host,Cmnd}_Alias or you have a user or  host
             name  listed that consists solely of uppercase letters, digits, and the underscore (‘_’) character.
             In the latter case, you can ignore the warnings (sudo will not complain).  The message is  prefixed
             with  the path name of the sudoers file and the line number where the undefined alias was used.  In
             -s (strict) mode these are errors, not warnings.

       Warning:unused{User,Runas,Host,Cmnd}_Alias
             The specified {User,Runas,Host,Cmnd}_Alias was defined but never used.   The  message  is  prefixed
             with the path name of the sudoers file and the line number where the unused alias was defined.  You
             may wish to comment out or remove the unused alias.

       Warning:cyclein{User,Runas,Host,Cmnd}_Alias
             The  specified  {User,Runas,Host,Cmnd}_Alias  includes  a  reference  to itself, either directly or
             through an alias it includes.  The message is prefixed with the path name of the sudoers  file  and
             the  line  number  where the cycle was detected.  This is only a warning unless visudo is run in -s
             (strict) mode as sudo will ignore cycles when parsing the sudoers file.

       ignoringeditorbackupfile
             While processing a @includedir or #includedir, a file was found with a name that  ends  in  ‘~’  or
             .bak.  Such files are skipped by sudo and visudo.

       ignoringfilenamecontaining'.'
             While  processing  a  @includedir  or #includedir, a file was found with a name that contains a ‘.’
             character.  Such files are skipped by sudo and visudo.

       unknowndefaultsentry"name"
             The sudoers file contains a Defaults setting not recognized by visudo.

visudo is provided “AS IS” and any express or implied warranties, including,  but  not  limited  to,  the
       implied  warranties  of  merchantability  and  fitness  for a particular purpose are disclaimed.  See the
       LICENSE.md file distributed with sudo or https://www.sudo.ws/about/license/ for complete details.

Sudo 1.9.16p2                                     July 27, 2023                                        VISUDO(8)

       The  following environment variables may be consulted depending on the value of the editor and env_editorsudoers settings:

       SUDO_EDITOR      Invoked by visudo as the editor to use

       VISUAL           Used by visudo if SUDO_EDITOR is not set

       EDITOR           Used by visudo if neither SUDO_EDITOR nor VISUAL is set

/etc/sudo.conf            Sudo front-end configuration

       /etc/sudoers              List of who can run what

       /etc/sudoers.tmp          Default temporary file used by visudo

       visudo — edit the sudoers file

vi(1), sudo.conf(5), sudoers(5), sudo(8), vipw(8)

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       https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search the archives.

visudo [-chIOPqsV] [[-f] sudoers]