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VISUDO(8)		FreeBSD	System Manager's Manual		     VISUDO(8)

NAME
     visudo -- edit the	sudoers	file

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

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

     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 er-
     ror, so will sudo.	 If `e'	is typed to edit the sudoers file after	a syn-
     tax 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 possi-
	       ble, or the first editor	in the list that exists	and is exe-
	       cutable.	 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/vi 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 de-
	       fault editor list.  visudo is typically run as root so this op-
	       tion 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 stan-
		 dard 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 encoun-
		 tered,	visudo will exit with a	value of 1.

     -f	sudoers, --file=sudoers
		 Specify an alternate sudoers file location, see below.	 As of
		 version 1.8.27, the sudoers path can be specified without us-
		 ing 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 re-
		 ported	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 re-
		 ported	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,
     /usr/local/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.  Be-
     cause the policy is evaluated in its entirety, it is not sufficient to
     check an individual sudoers include file for syntax errors.

   Debugging and sudoers plugin	arguments
     visudo 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.

ENVIRONMENT
     The following environment variables may be	consulted depending on the
     value of the editor and env_editor	sudoers	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

FILES
     /usr/local/etc/sudo.conf  Sudo front-end configuration

     /usr/local/etc/sudoers    List of who can run what

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

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

     sudoers file busy,	try again later.
	   Someone else	is currently editing the sudoers file.

     /usr/local/etc/sudoers: Permission	denied
	   You didn't run visudo as root.

     you do not	exist in the passwd database
	   Your	user-ID	does not appear	in the system passwd database.

     Warning: {User,Runas,Host,Cmnd}_Alias referenced but not defined
	   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 under-
	   score (`_') 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 un-
	   defined 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: cycle in {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 mes-
	   sage	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.

     unknown defaults entry "name"
	   The sudoers file contains a Defaults	setting	not recognized by
	   visudo.

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

AUTHORS
     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 peo-
     ple who have contributed to sudo.

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

BUGS
     If	you believe you	have found a bug in visudo, you	can submit a bug re-
     port at https://bugzilla.sudo.ws/

SUPPORT
     Limited free support is available via the sudo-users mailing list,	see
     https://www.sudo.ws/mailman/listinfo/sudo-users to	subscribe or search
     the archives.

DISCLAIMER
     visudo is provided	"AS IS"	and any	express	or implied warranties, includ-
     ing, 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 1.9.12p1			October	4, 2022			 Sudo 1.9.12p1

NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | FILES | DIAGNOSTICS | SEE ALSO | AUTHORS | CAVEATS | BUGS | SUPPORT | DISCLAIMER

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