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SUDOERS(5)		  FreeBSD File Formats Manual		    SUDOERS(5)

NAME
     sudoers --	default	sudo security policy plugin

DESCRIPTION
     The sudoers policy	plugin determines a user's sudo	privileges.  It	is the
     default sudo policy plugin.  The policy is	driven by the
     /usr/local/etc/sudoers file or, optionally	in LDAP.  The policy format is
     described in detail in the	SUDOERS	FILE FORMAT section.  For information
     on	storing	sudoers	policy information in LDAP, please see
     sudoers.ldap(5).

   Configuring sudo.conf for sudoers
     sudo consults the sudo.conf(5) file to determine which policy and and I/O
     logging plugins to	load.  If no sudo.conf(5) file is present, or if it
     contains no Plugin	lines, sudoers will be used for	policy decisions and
     I/O logging.  To explicitly configure sudo.conf(5)	to use the sudoers
     plugin, the following configuration can be	used.

	   Plugin sudoers_policy sudoers.so
	   Plugin sudoers_io sudoers.so

     Starting with sudo	1.8.5, it is possible to specify optional arguments to
     the sudoers plugin	in the sudo.conf(5) file.  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 plugin arguments are	supported:

     ldap_conf=pathname
	       The ldap_conf argument can be used to override the default path
	       to the ldap.conf	file.

     ldap_secret=pathname
	       The ldap_secret argument	can be used to override	the default
	       path to the ldap.secret file.

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

     sudoers_uid=uid
	       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=gid
	       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), please refer to its
     manual.

   User	Authentication
     The sudoers security policy requires that most users authenticate them-
     selves before they	can use	sudo.  A password is not required if the
     invoking user is root, if the target user is the same as the invoking
     user, or if the policy has	disabled authentication	for the	user or	com-
     mand.  Unlike su(1), when sudoers requires	authentication,	it validates
     the invoking user's credentials, not the target user's (or	root's)	cre-
     dentials.	This can be changed via	the rootpw, targetpw and runaspw
     flags, described later.

     If	a user who is not listed in the	policy tries to	run a command via
     sudo, mail	is sent	to the proper authorities.  The	address	used for such
     mail is configurable via the mailto Defaults entry	(described later) and
     defaults to root.

     Note that no mail will be sent if an unauthorized user tries to run sudo
     with the -l or -v option unless there is an authentication	error and
     either the	mail_always or mail_badpass flags are enabled.	This allows
     users to determine	for themselves whether or not they are allowed to use
     sudo.  All	attempts to run	sudo (successful or not) will be logged,
     regardless	of whether or not mail is sent.

     If	sudo is	run by root and	the SUDO_USER environment variable is set, the
     sudoers policy will use this value	to determine who the actual user is.
     This can be used by a user	to log commands	through	sudo even when a root
     shell has been invoked.  It also allows the -e option to remain useful
     even when invoked via a sudo-run script or	program.  Note,	however, that
     the sudoers file lookup is	still done for root, not the user specified by
     SUDO_USER.

     sudoers uses per-user time	stamp files for	credential caching.  Once a
     user has been authenticated, a record is written containing the uid that
     was used to authenticate, the terminal session ID,	and a time stamp
     (using a monotonic	clock if one is	available).  The user may then use
     sudo without a password for a short period	of time	(5 minutes unless
     overridden	by the timestamp_timeout option).  By default, sudoers uses a
     separate record for each tty, which means that a user's login sessions
     are authenticated separately.  The	tty_tickets option can be disabled to
     force the use of a	single time stamp for all of a user's sessions.

   Logging
     sudoers can log both successful and unsuccessful attempts (as well	as
     errors) to	syslog(3), a log file, or both.	 By default, sudoers will log
     via syslog(3) but this is changeable via the syslog and logfile Defaults
     settings.	See LOG	FORMAT for a description of the	log file format.

     sudoers is	also capable of	running	a command in a pseudo-tty and logging
     all input and/or output.  The standard input, standard output and stan-
     dard error	can be logged even when	not associated with a terminal.	 I/O
     logging is	not on by default but can be enabled using the log_input and
     log_output	options	as well	as the LOG_INPUT and LOG_OUTPUT	command	tags.
     See I/O LOG FILES for details on how I/O log files	are stored.

   Command environment
     Since environment variables can influence program behavior, sudoers pro-
     vides a means to restrict which variables from the	user's environment are
     inherited by the command to be run.  There	are two	distinct ways sudoers
     can deal with environment variables.

     By	default, the env_reset option is enabled.  This	causes commands	to be
     executed with a new, minimal environment.	On AIX (and Linux systems
     without PAM), the environment is initialized with the contents of the
     /etc/environment file.  On	BSD systems, if	the use_loginclass option is
     enabled, the environment is initialized based on the path and setenv set-
     tings in /etc/login.conf.	The new	environment contains the TERM, PATH,
     HOME, MAIL, SHELL,	LOGNAME, USER, USERNAME	and SUDO_* variables in	addi-
     tion to variables from the	invoking process permitted by the env_check
     and env_keep options.  This is effectively	a whitelist for	environment
     variables.	 Environment variables with a value beginning with () are
     removed unless both the name and value parts are matched by env_keep or
     env_check,	as they	will be	interpreted as functions by older versions of
     the bash shell.  Prior to version 1.8.11, such variables were always
     removed.

     If, however, the env_reset	option is disabled, any	variables not explic-
     itly denied by the	env_check and env_delete options are inherited from
     the invoking process.  In this case, env_check and	env_delete behave like
     a blacklist.  Environment variables with a	value beginning	with ()	are
     always removed, even if they do not match one of the blacklists.  Since
     it	is not possible	to blacklist all potentially dangerous environment
     variables,	use of the default env_reset behavior is encouraged.

     By	default, environment variables are matched by name.  However, if the
     pattern includes an equal sign (`='), both	the variables name and value
     must match.  For example, an old-style (pre-shellshock) bash shell	func-
     tion could	be matched as follows:

	 env_keep += "my_func=()*"

     Without the ``=()*'' suffix, this would not match,	as old-style bash
     shell functions are not preserved by default.

     The complete list of environment variables	that sudo allows or denies is
     contained in the output of	``sudo -V'' when run as	root.  Please note
     that this list varies based on the	operating system sudo is running on.

     On	systems	that support PAM where the pam_env module is enabled for sudo,
     variables in the PAM environment may be merged in to the environment.  If
     a variable	in the PAM environment is already present in the user's	envi-
     ronment, the value	will only be overridden	if the variable	was not	pre-
     served by sudoers.	 When env_reset	is enabled, variables preserved	from
     the invoking user's environment by	the env_keep list take precedence over
     those in the PAM environment.  When env_reset is disabled,	variables
     present the invoking user's environment take precedence over those	in the
     PAM environment unless they match a pattern in the	env_delete list.

     Note that the dynamic linker on most operating systems will remove	vari-
     ables that	can control dynamic linking from the environment of setuid
     executables, including sudo.  Depending on	the operating system this may
     include _RLD*, DYLD_*, LD_*, LDR_*, LIBPATH, SHLIB_PATH, and others.
     These type	of variables are removed from the environment before sudo even
     begins execution and, as such, it is not possible for sudo	to preserve
     them.

     As	a special case,	if sudo's -i option (initial login) is specified,
     sudoers will initialize the environment regardless	of the value of
     env_reset.	 The DISPLAY, PATH and TERM variables remain unchanged;	HOME,
     MAIL, SHELL, USER,	and LOGNAME are	set based on the target	user.  On AIX
     (and Linux	systems	without	PAM), the contents of /etc/environment are
     also included.  On	BSD systems, if	the use_loginclass flag	is enabled,
     the path and setenv variables in /etc/login.conf are also applied.	 All
     other environment variables are removed.

     Finally, the restricted_env_file and env_file files are applied, if
     present.  The variables in	restricted_env_file are	applied	first and are
     subject to	the same restrictions as the invoking user's environment, as
     detailed above.  The variables in env_file	are applied last and are not
     subject to	these restrictions.  In	both cases, variables present in the
     files will	only be	set to their specified values if they would not	con-
     flict with	an existing environment	variable.

SUDOERS	FILE FORMAT
     The sudoers file is composed of two types of entries: aliases (basically
     variables)	and user specifications	(which specify who may run what).

     When multiple entries match for a user, they are applied in order.	 Where
     there are multiple	matches, the last match	is used	(which is not neces-
     sarily the	most specific match).

     The sudoers file grammar will be described	below in Extended Backus-Naur
     Form (EBNF).  Don't despair if you	are unfamiliar with EBNF; it is	fairly
     simple, and the definitions below are annotated.

   Quick guide to EBNF
     EBNF is a concise and exact way of	describing the grammar of a language.
     Each EBNF definition is made up of	production rules.  E.g.,

     symbol ::=	definition | alternate1	| alternate2 ...

     Each production rule references others and	thus makes up a	grammar	for
     the language.  EBNF also contains the following operators,	which many
     readers will recognize from regular expressions.  Do not, however,	con-
     fuse them with ``wildcard'' characters, which have	different meanings.

     ?	   Means that the preceding symbol (or group of	symbols) is optional.
	   That	is, it may appear once or not at all.

     *	   Means that the preceding symbol (or group of	symbols) may appear
	   zero	or more	times.

     +	   Means that the preceding symbol (or group of	symbols) may appear
	   one or more times.

     Parentheses may be	used to	group symbols together.	 For clarity, we will
     use single	quotes ('') to designate what is a verbatim character string
     (as opposed to a symbol name).

   Aliases
     There are four kinds of aliases: User_Alias, Runas_Alias, Host_Alias and
     Cmnd_Alias.

     Alias ::= 'User_Alias'  User_Alias	(':' User_Alias)* |
	       'Runas_Alias' Runas_Alias (':' Runas_Alias)* |
	       'Host_Alias'  Host_Alias	(':' Host_Alias)* |
	       'Cmnd_Alias'  Cmnd_Alias	(':' Cmnd_Alias)*

     User_Alias	::= NAME '=' User_List

     Runas_Alias ::= NAME '=' Runas_List

     Host_Alias	::= NAME '=' Host_List

     Cmnd_Alias	::= NAME '=' Cmnd_List

     NAME ::= [A-Z]([A-Z][0-9]_)*

     Each alias	definition is of the form

     Alias_Type	NAME = item1, item2, ...

     where Alias_Type is one of	User_Alias, Runas_Alias, Host_Alias, or
     Cmnd_Alias.  A NAME is a string of	uppercase letters, numbers, and	under-
     score characters (`_').  A	NAME must start	with an	uppercase letter.  It
     is	possible to put	several	alias definitions of the same type on a	single
     line, joined by a colon (`:').  E.g.,

     Alias_Type	NAME = item1, item2, item3 : NAME = item4, item5

     It	is a syntax error to redefine an existing alias.  It is	possible to
     use the same name for aliases of different	types, but this	is not recom-
     mended.

     The definitions of	what constitutes a valid alias member follow.

     User_List ::= User	|
		   User	',' User_List

     User ::= '!'* user	name |
	      '!'* #uid	|
	      '!'* %group |
	      '!'* %#gid |
	      '!'* +netgroup |
	      '!'* %:nonunix_group |
	      '!'* %:#nonunix_gid |
	      '!'* User_Alias

     A User_List is made up of one or more user	names, user IDs	(prefixed with
     `#'), system group	names and IDs (prefixed	with `%' and `%#' respec-
     tively), netgroups	(prefixed with `+'), non-Unix group names and IDs
     (prefixed with `%:' and `%:#' respectively) and User_Aliases. Each	list
     item may be prefixed with zero or more `!'	operators.  An odd number of
     `!' operators negate the value of the item; an even number	just cancel
     each other	out.  User netgroups are matched using the user	and domain
     members only; the host member is not used when matching.

     A user name, uid, group, gid, netgroup, nonunix_group or nonunix_gid may
     be	enclosed in double quotes to avoid the need for	escaping special char-
     acters.  Alternately, special characters may be specified in escaped hex
     mode, e.g.	\x20 for space.	 When using double quotes, any prefix charac-
     ters must be included inside the quotes.

     The actual	nonunix_group and nonunix_gid syntax depends on	the underlying
     group provider plugin.  For instance, the QAS AD plugin supports the fol-
     lowing formats:

     +o	   Group in the	same domain: "%:Group Name"

     +o	   Group in any	domain:	"%:Group Name@FULLY.QUALIFIED.DOMAIN"

     +o	   Group SID: "%:S-1-2-34-5678901234-5678901234-5678901234-567"

     See GROUP PROVIDER	PLUGINS	for more information.

     Note that quotes around group names are optional.	Unquoted strings must
     use a backslash (`\') to escape spaces and	special	characters.  See Other
     special characters	and reserved words for a list of characters that need
     to	be escaped.

     Runas_List	::= Runas_Member |
		    Runas_Member ',' Runas_List

     Runas_Member ::= '!'* user	name |
		      '!'* #uid	|
		      '!'* %group |
		      '!'* %#gid |
		      '!'* %:nonunix_group |
		      '!'* %:#nonunix_gid |
		      '!'* +netgroup |
		      '!'* Runas_Alias

     A Runas_List is similar to	a User_List except that	instead	of
     User_Aliases it can contain Runas_Aliases.	 Note that user	names and
     groups are	matched	as strings.  In	other words, two users (groups)	with
     the same uid (gid)	are considered to be distinct.	If you wish to match
     all user names with the same uid (e.g. root and toor), you	can use	a uid
     instead (#0 in the	example	given).

     Host_List ::= Host	|
		   Host	',' Host_List

     Host ::= '!'* host	name |
	      '!'* ip_addr |
	      '!'* network(/netmask)? |
	      '!'* +netgroup |
	      '!'* Host_Alias

     A Host_List is made up of one or more host	names, IP addresses, network
     numbers, netgroups	(prefixed with `+') and	other aliases.	Again, the
     value of an item may be negated with the `!' operator.  Host netgroups
     are matched using the host	(both qualified	and unqualified) and domain
     members only; the user member is not used when matching.  If you specify
     a network number without a	netmask, sudo will query each of the local
     host's network interfaces and, if the network number corresponds to one
     of	the hosts's network interfaces,	will use the netmask of	that inter-
     face.  The	netmask	may be specified either	in standard IP address nota-
     tion (e.g.	255.255.255.0 or ffff:ffff:ffff:ffff::), or CIDR notation
     (number of	bits, e.g. 24 or 64).  A host name may include shell-style
     wildcards (see the	Wildcards section below), but unless the host name
     command on	your machine returns the fully qualified host name, you'll
     need to use the fqdn option for wildcards to be useful.  Note that	sudo
     only inspects actual network interfaces; this means that IP address
     127.0.0.1 (localhost) will	never match.  Also, the	host name
     ``localhost'' will	only match if that is the actual host name, which is
     usually only the case for non-networked systems.

     digest ::=	[A-Fa-f0-9]+ |
		[[A-Za-z0-9+/=]+

     Digest_Spec ::= "sha224" ':' digest |
		     "sha256" ':' digest |
		     "sha384" ':' digest |
		     "sha512" ':' digest

     Cmnd_List ::= Cmnd	|
		   Cmnd	',' Cmnd_List

     command name ::= file name	|
		      file name	args |
		      file name	'""'

     Cmnd ::= Digest_Spec? '!'*	command	name |
	      '!'* directory |
	      '!'* "sudoedit" |
	      '!'* Cmnd_Alias

     A Cmnd_List is a list of one or more command names, directories, and
     other aliases.  A command name is a fully qualified file name which may
     include shell-style wildcards (see	the Wildcards section below).  A sim-
     ple file name allows the user to run the command with any arguments
     he/she wishes.  However, you may also specify command line	arguments
     (including	wildcards).  Alternately, you can specify "" to	indicate that
     the command may only be run without command line arguments.  A directory
     is	a fully	qualified path name ending in a	`/'.  When you specify a
     directory in a Cmnd_List, the user	will be	able to	run any	file within
     that directory (but not in	any sub-directories therein).

     If	a Cmnd has associated command line arguments, then the arguments in
     the Cmnd must match exactly those given by	the user on the	command	line
     (or match the wildcards if	there are any).	 Note that the following char-
     acters must be escaped with a `\' if they are used	in command arguments:
     `,', `:', `=', `\'.  The built-in command ``sudoedit'' is used to permit
     a user to run sudo	with the -e option (or as sudoedit).  It may take com-
     mand line arguments just as a normal command does.	 Note that
     ``sudoedit'' is a command built into sudo itself and must be specified in
     the sudoers file without a	leading	path.

     If	a command name is prefixed with	a Digest_Spec, the command will	only
     match successfully	if it can be verified using the	specified SHA-2
     digest.  The following digest formats are supported: sha224, sha256,
     sha384 and	sha512.	 The string may	be specified in	either hex or base64
     format (base64 is more compact).  There are several utilities capable of
     generating	SHA-2 digests in hex format such as openssl, shasum,
     sha224sum,	sha256sum, sha384sum, sha512sum.

     For example, using	openssl:

     $ openssl dgst -sha224 /bin/ls
     SHA224(/bin/ls)= 118187da8364d490b4a7debbf483004e8f3e053ec954309de2c41a25

     It	is also	possible to use	openssl	to generate base64 output:

     $ openssl dgst -binary -sha224 /bin/ls | openssl base64
     EYGH2oNk1JC0p9679IMATo8+BT7JVDCd4sQaJQ==

     Warning, if the user has write access to the command itself (directly or
     via a sudo	command), it may be possible for the user to replace the com-
     mand after	the digest check has been performed but	before the command is
     executed.	A similar race condition exists	on systems that	lack the
     fexecve(2)	system call when the directory in which	the command is located
     is	writable by the	user.  See the description of the fdexec setting for
     more information on how sudo executes commands that have an associated
     digest.

     Command digests are only supported	by version 1.8.7 or higher.

   Defaults
     Certain configuration options may be changed from their default values at
     run-time via one or more Default_Entry lines.  These may affect all users
     on	any host, all users on a specific host,	a specific user, a specific
     command, or commands being	run as a specific user.	 Note that per-command
     entries may not include command line arguments.  If you need to specify
     arguments,	define a Cmnd_Alias and	reference that instead.

     Default_Type ::= 'Defaults' |
		      'Defaults' '@' Host_List |
		      'Defaults' ':' User_List |
		      'Defaults' '!' Cmnd_List |
		      'Defaults' '>' Runas_List

     Default_Entry ::= Default_Type Parameter_List

     Parameter_List ::=	Parameter |
			Parameter ',' Parameter_List

     Parameter ::= Parameter '=' Value |
		   Parameter '+=' Value	|
		   Parameter '-=' Value	|
		   '!'*	Parameter

     Parameters	may be flags, integer values, strings, or lists.  Flags	are
     implicitly	boolean	and can	be turned off via the `!' operator.  Some
     integer, string and list parameters may also be used in a boolean context
     to	disable	them.  Values may be enclosed in double	quotes ("") when they
     contain multiple words.  Special characters may be	escaped	with a back-
     slash (`\').

     Lists have	two additional assignment operators, +=	and -=.	 These opera-
     tors are used to add to and delete	from a list respectively.  It is not
     an	error to use the -= operator to	remove an element that does not	exist
     in	a list.

     Defaults entries are parsed in the	following order: generic, host,	user
     and runas Defaults	first, then command defaults.  If there	are multiple
     Defaults settings of the same type, the last matching setting is used.
     The following Defaults settings are parsed	before all others since	they
     may affect	subsequent entries: fqdn, group_plugin,	runas_default,
     sudoers_locale.

     See SUDOERS OPTIONS for a list of supported Defaults parameters.

   User	specification
     User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
		   (':'	Host_List '=' Cmnd_Spec_List)*

     Cmnd_Spec_List ::=	Cmnd_Spec |
			Cmnd_Spec ',' Cmnd_Spec_List

     Cmnd_Spec ::= Runas_Spec? Option_Spec* Tag_Spec* Cmnd

     Runas_Spec	::= '('	Runas_List? (':' Runas_List)? ')'

     Option_Spec ::= (Date_Spec	| Timeout_Spec)

     Date_Spec ::= ('NOTBEFORE=timestamp' | 'NOTAFTER=timestamp')

     Timeout_Spec ::= 'TIMEOUT=timeout'

     Tag_Spec ::= ('EXEC:' | 'NOEXEC:' | 'FOLLOW:' | 'NOFOLLOW'	|
		   'LOG_INPUT:'	| 'NOLOG_INPUT:' | 'LOG_OUTPUT:' |
		   'NOLOG_OUTPUT:' | 'MAIL:' | 'NOMAIL:' | 'PASSWD:' |
		   'NOPASSWD:' | 'SETENV:' | 'NOSETENV:')

     A user specification determines which commands a user may run (and	as
     what user)	on specified hosts.  By	default, commands are run as root, but
     this can be changed on a per-command basis.

     The basic structure of a user specification is ``who where	= (as_whom)
     what''.  Let's break that down into its constituent parts:

   Runas_Spec
     A Runas_Spec determines the user and/or the group that a command may be
     run as.  A	fully-specified	Runas_Spec consists of two Runas_Lists (as
     defined above) separated by a colon (`:') and enclosed in a set of	paren-
     theses.  The first	Runas_List indicates which users the command may be
     run as via	sudo's -u option.  The second defines a	list of	groups that
     can be specified via sudo's -g option.  If	both Runas_Lists are speci-
     fied, the command may be run with any combination of users	and groups
     listed in their respective	Runas_Lists. If	only the first is specified,
     the command may be	run as any user	in the list but	no -g option may be
     specified.	 If the	first Runas_List is empty but the second is specified,
     the command may be	run as the invoking user with the group	set to any
     listed in the Runas_List.	If both	Runas_Lists are	empty, the command may
     only be run as the	invoking user.	If no Runas_Spec is specified the com-
     mand may be run as	root and no group may be specified.

     A Runas_Spec sets the default for the commands that follow	it.  What this
     means is that for the entry:

     dgb     boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm

     The user dgb may run /bin/ls, /bin/kill, and /usr/bin/lprm--but only as
     operator.	E.g.,

     $ sudo -u operator	/bin/ls

     It	is also	possible to override a Runas_Spec later	on in an entry.	 If we
     modify the	entry like so:

     dgb     boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm

     Then user dgb is now allowed to run /bin/ls as operator, but /bin/kill
     and /usr/bin/lprm as root.

     We	can extend this	to allow dgb to	run /bin/ls with either	the user or
     group set to operator:

     dgb     boulder = (operator : operator) /bin/ls, (root) /bin/kill,\
	     /usr/bin/lprm

     Note that while the group portion of the Runas_Spec permits the user to
     run as command with that group, it	does not force the user	to do so.  If
     no	group is specified on the command line,	the command will run with the
     group listed in the target	user's password	database entry.	 The following
     would all be permitted by the sudoers entry above:

     $ sudo -u operator	/bin/ls
     $ sudo -u operator	-g operator /bin/ls
     $ sudo -g operator	/bin/ls

     In	the following example, user tcm	may run	commands that access a modem
     device file with the dialer group.

     tcm     boulder = (:dialer) /usr/bin/tip, /usr/bin/cu,\
	     /usr/local/bin/minicom

     Note that in this example only the	group will be set, the command still
     runs as user tcm.	E.g.

     $ sudo -g dialer /usr/bin/cu

     Multiple users and	groups may be present in a Runas_Spec, in which	case
     the user may select any combination of users and groups via the -u	and -g
     options.  In this example:

     alan    ALL = (root, bin :	operator, system) ALL

     user alan may run any command as either user root or bin, optionally set-
     ting the group to operator	or system.

   Option_Spec
     A Cmnd may	have zero or more options associated with it.  Depending on
     the system, options may consist of	SELinux	roles and/or types, Solaris
     privileges	sets, and command timeouts.  Once an option is set for a Cmnd,
     subsequent	Cmnds in the Cmnd_Spec_List, inherit that option unless	it is
     overridden	by another option.

   Date_Spec
     sudoers rules can be specified with a start and end date via the
     NOTBEFORE and NOTAFTER settings.  The time	stamp must be specified	in
     Generalized Time as defined by RFC	4517.  The format is effectively
     yyyymmddHHMMSSZ where the minutes and seconds are optional.  The `Z' suf-
     fix indicates that	the time stamp is in Coordinated Universal Time	(UTC).
     It	is also	possible to specify a timezone offset from UTC in hours	and
     minutes instead of	a `Z'.	For example, `-0500' would correspond to East-
     ern Standard time in the US.  As an extension, if no `Z' or timezone off-
     set is specified, local time will be used.

     The following are all valid time stamps:

	 20170214083000Z
	 2017021408Z
	 20160315220000-0500
	 20151201235900

   Timeout_Spec
     A command may have	a timeout associated with it.  If the timeout expires
     before the	command	has exited, the	command	will be	terminated.  The time-
     out may be	specified in combinations of days, hours, minutes and seconds
     with a single-letter case-insensitive suffix that indicates the unit of
     time.  For	example, a timeout of 7	days, 8	hours, 30 minutes and 10 sec-
     onds would	be written as 7d8h30m10s.  If a	number is specified without a
     unit, seconds are assumed.	 Any of	the days, minutes, hours or seconds
     may be omitted.  The order	must be	from largest to	smallest unit and a
     unit may not be specified more than once.

     The following are all valid timeout values: 7d8h30m10s, 14d, 8h30m, 600s,
     3600.  The	following are invalid timeout values: 12m2w1d, 30s10m4h,
     1d2d3h.

     This option is only supported by version 1.8.20 or	higher.

   Tag_Spec
     A command may have	zero or	more tags associated with it.  The following
     tag values	are supported: EXEC, NOEXEC, FOLLOW, NOFOLLOW, LOG_INPUT,
     NOLOG_INPUT, LOG_OUTPUT, NOLOG_OUTPUT, MAIL, NOMAIL, PASSWD, NOPASSWD,
     SETENV, and NOSETENV.  Once a tag is set on a Cmnd, subsequent Cmnds in
     the Cmnd_Spec_List, inherit the tag unless	it is overridden by the	oppo-
     site tag (in other	words, PASSWD overrides	NOPASSWD and NOEXEC overrides
     EXEC).

     EXEC and NOEXEC

       If sudo has been	compiled with noexec support and the underlying	oper-
       ating system supports it, the NOEXEC tag	can be used to prevent a
       dynamically-linked executable from running further commands itself.

       In the following	example, user aaron may	run /usr/bin/more and
       /usr/bin/vi but shell escapes will be disabled.

       aaron   shanty =	NOEXEC:	/usr/bin/more, /usr/bin/vi

       See the Preventing shell	escapes	section	below for more details on how
       NOEXEC works and	whether	or not it will work on your system.

     FOLLOW and	NOFOLLOW Starting with version 1.8.15, sudoedit	will not open
       a file that is a	symbolic link unless the sudoedit_follow option	is
       enabled.	 The FOLLOW and	NOFOLLOW tags override the value of
       sudoedit_follow and can be used to permit (or deny) the editing of sym-
       bolic links on a	per-command basis.  These tags are only	effective for
       the sudoedit command and	are ignored for	all other commands.

     LOG_INPUT and NOLOG_INPUT

       These tags override the value of	the log_input option on	a per-command
       basis.  For more	information, see the description of log_input in the
       SUDOERS OPTIONS section below.

     LOG_OUTPUT	and NOLOG_OUTPUT

       These tags override the value of	the log_output option on a per-command
       basis.  For more	information, see the description of log_output in the
       SUDOERS OPTIONS section below.

     MAIL and NOMAIL

       These tags provide fine-grained control over whether mail will be sent
       when a user runs	a command by overriding	the value of the
       mail_all_cmnds option on	a per-command basis.  They have	no effect when
       sudo is run with	the -l or -v options.  A NOMAIL	tag will also override
       the mail_always and mail_no_perms options.  For more information, see
       the descriptions	of mail_all_cmnds, mail_always,	and mail_no_perms in
       the SUDOERS OPTIONS section below.

     PASSWD and	NOPASSWD

       By default, sudo	requires that a	user authenticate him or herself
       before running a	command.  This behavior	can be modified	via the
       NOPASSWD	tag.  Like a Runas_Spec, the NOPASSWD tag sets a default for
       the commands that follow	it in the Cmnd_Spec_List.  Conversely, the
       PASSWD tag can be used to reverse things.  For example:

       ray     rushmore	= NOPASSWD: /bin/kill, /bin/ls,	/usr/bin/lprm

       would allow the user ray	to run /bin/kill, /bin/ls, and /usr/bin/lprm
       as root on the machine rushmore without authenticating himself.	If we
       only want ray to	be able	to run /bin/kill without a password the	entry
       would be:

       ray     rushmore	= NOPASSWD: /bin/kill, PASSWD: /bin/ls,	/usr/bin/lprm

       Note, however, that the PASSWD tag has no effect	on users who are in
       the group specified by the exempt_group option.

       By default, if the NOPASSWD tag is applied to any of the	entries	for a
       user on the current host, he or she will	be able	to run ``sudo -l''
       without a password.  Additionally, a user may only run ``sudo -v''
       without a password if the NOPASSWD tag is present for all a user's
       entries that pertain to the current host.  This behavior	may be over-
       ridden via the verifypw and listpw options.

     SETENV and	NOSETENV

       These tags override the value of	the setenv option on a per-command
       basis.  Note that if SETENV has been set	for a command, the user	may
       disable the env_reset option from the command line via the -E option.
       Additionally, environment variables set on the command line are not
       subject to the restrictions imposed by env_check, env_delete, or
       env_keep.  As such, only	trusted	users should be	allowed	to set vari-
       ables in	this manner.  If the command matched is	ALL, the SETENV	tag is
       implied for that	command; this default may be overridden	by use of the
       NOSETENV	tag.

   Wildcards
     sudo allows shell-style wildcards (aka meta or glob characters) to	be
     used in host names, path names and	command	line arguments in the sudoers
     file.  Wildcard matching is done via the glob(3) and fnmatch(3) functions
     as	specified by IEEE Std 1003.1 (``POSIX.1'').

     *	       Matches any set of zero or more characters (including white
	       space).

     ?	       Matches any single character (including white space).

     [...]     Matches any character in	the specified range.

     [!...]    Matches any character not in the	specified range.

     \x	       For any character `x', evaluates	to `x'.	 This is used to
	       escape special characters such as: `*', `?', `[', and `]'.

     Note that these are not regular expressions.  Unlike a regular expression
     there is no way to	match one or more characters within a range.

     Character classes may be used if your system's glob(3) and	fnmatch(3)
     functions support them.  However, because the `:' character has special
     meaning in	sudoers, it must be escaped.  For example:

	 /bin/ls [[\:alpha\:]]*

     Would match any file name beginning with a	letter.

     Note that a forward slash (`/') will not be matched by wildcards used in
     the file name portion of the command.  This is to make a path like:

	 /usr/bin/*

     match /usr/bin/who	but not	/usr/bin/X11/xterm.

     When matching the command line arguments, however,	a slash	does get
     matched by	wildcards since	command	line arguments may contain arbitrary
     strings and not just path names.

     Wildcards in command line arguments should	be used	with care.
     Command line arguments are	matched	as a single, concatenated string.
     This mean a wildcard character such as `?'	or `*' will match across word
     boundaries, which may be unexpected.  For example,	while a	sudoers	entry
     like:

	 %operator ALL = /bin/cat /var/log/messages*

     will allow	command	like:

	 $ sudo	cat /var/log/messages.1

     It	will also allow:

	 $ sudo	cat /var/log/messages /etc/shadow

     which is probably not what	was intended.  In most cases it	is better to
     do	command	line processing	outside	of the sudoers file in a scripting
     language.

   Exceptions to wildcard rules
     The following exceptions apply to the above rules:

     ""	       If the empty string "" is the only command line argument	in the
	       sudoers file entry it means that	command	is not allowed to be
	       run with	any arguments.

     sudoedit  Command line arguments to the sudoedit built-in command should
	       always be path names, so	a forward slash	(`/') will not be
	       matched by a wildcard.

   Including other files from within sudoers
     It	is possible to include other sudoers files from	within the sudoers
     file currently being parsed using the #include and	#includedir direc-
     tives.

     This can be used, for example, to keep a site-wide	sudoers	file in	addi-
     tion to a local, per-machine file.	 For the sake of this example the
     site-wide sudoers file will be /etc/sudoers and the per-machine one will
     be	/etc/sudoers.local.  To	include	/etc/sudoers.local from	within
     /etc/sudoers we would use the following line in /etc/sudoers:

	 #include /etc/sudoers.local

     When sudo reaches this line it will suspend processing of the current
     file (/etc/sudoers) and switch to /etc/sudoers.local.  Upon reaching the
     end of /etc/sudoers.local,	the rest of /etc/sudoers will be processed.
     Files that	are included may themselves include other files.  A hard limit
     of	128 nested include files is enforced to	prevent	include	file loops.

     If	the path to the	include	file is	not fully-qualified (does not begin
     with a `/', it must be located in the same	directory as the sudoers file
     it	was included from.  For	example, if /etc/sudoers contains the line:

	 #include sudoers.local

     the file that will	be included is /etc/sudoers.local.

     The file name may also include the	%h escape, signifying the short	form
     of	the host name.	In other words,	if the machine's host name is
     ``xerxes'', then

	 #include /etc/sudoers.%h

     will cause	sudo to	include	the file /etc/sudoers.xerxes.

     The #includedir directive can be used to create a sudoers.d directory
     that the system package manager can drop sudoers file rules into as part
     of	package	installation.  For example, given:

	 #includedir /etc/sudoers.d

     sudo will suspend processing of the current file and read each file in
     /etc/sudoers.d, skipping file names that end in `~' or contain a `.'
     character to avoid	causing	problems with package manager or editor	tempo-
     rary/backup files.	 Files are parsed in sorted lexical order.  That is,
     /etc/sudoers.d/01_first will be parsed before /etc/sudoers.d/10_second.
     Be	aware that because the sorting is lexical, not numeric,
     /etc/sudoers.d/1_whoops would be loaded after /etc/sudoers.d/10_second.
     Using a consistent	number of leading zeroes in the	file names can be used
     to	avoid such problems.  After parsing the	files in the directory,	con-
     trol returns to the file that contained the #includedir directive.

     Note that unlike files included via #include, visudo will not edit	the
     files in a	#includedir directory unless one of them contains a syntax
     error.  It	is still possible to run visudo	with the -f flag to edit the
     files directly, but this will not catch the redefinition of an alias that
     is	also present in	a different file.

   Other special characters and	reserved words
     The pound sign (`#') is used to indicate a	comment	(unless	it is part of
     a #include	directive or unless it occurs in the context of	a user name
     and is followed by	one or more digits, in which case it is	treated	as a
     uid).  Both the comment character and any text after it, up to the	end of
     the line, are ignored.

     The reserved word ALL is a	built-in alias that always causes a match to
     succeed.  It can be used wherever one might otherwise use a Cmnd_Alias,
     User_Alias, Runas_Alias, or Host_Alias.  You should not try to define
     your own alias called ALL as the built-in alias will be used in prefer-
     ence to your own.	Please note that using ALL can be dangerous since in a
     command context, it allows	the user to run	any command on the system.

     An	exclamation point (`!')	can be used as a logical not operator in a
     list or alias as well as in front of a Cmnd.  This	allows one to exclude
     certain values.  For the `!' operator to be effective, there must be
     something for it to exclude.  For example,	to match all users except for
     root one would use:

	 ALL,!root

     If	the ALL, is omitted, as	in:

	 !root

     it	would explicitly deny root but not match any other users.  This	is
     different from a true ``negation''	operator.

     Note, however, that using a `!' in	conjunction with the built-in ALL
     alias to allow a user to run ``all	but a few'' commands rarely works as
     intended (see SECURITY NOTES below).

     Long lines	can be continued with a	backslash (`\')	as the last character
     on	the line.

     White space between elements in a list as well as special syntactic char-
     acters in a User Specification (`=', `:', `(', `)') is optional.

     The following characters must be escaped with a backslash (`\') when used
     as	part of	a word (e.g. a user name or host name):	`!', `=', `:', `,',
     `(', `)', `\'.

SUDOERS	OPTIONS
     sudo's behavior can be modified by	Default_Entry lines, as	explained ear-
     lier.  A list of all supported Defaults parameters, grouped by type, are
     listed below.

     Boolean Flags:

     always_query_group_plugin
		       If a group_plugin is configured,	use it to resolve
		       groups of the form %group as long as there is not also
		       a system	group of the same name.	 Normally, only	groups
		       of the form %:group are passed to the group_plugin.
		       This flag is off	by default.

     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 option is always implied.  Note that	by
		       default,	HOME will be set to the	home directory of the
		       target user when	the env_reset option is	enabled, so
		       always_set_home only has	an effect for configurations
		       where either env_reset is disabled or HOME is present
		       in the env_keep list.  This flag	is off by default.

     authenticate      If set, users must authenticate themselves via a	pass-
		       word (or	other means of authentication) before they may
		       run commands.  This default may be overridden via the
		       PASSWD and NOPASSWD tags.  This flag is on by default.

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

     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.

     exec_background   By default, sudo	runs a command as the foreground
		       process as long as sudo itself is running in the	fore-
		       ground.	When the exec_background flag is enabled and
		       the command is being run	in a pty (due to I/O logging
		       or the use_pty flag), the command will be run as	a
		       background process.  Attempts to	read from the control-
		       ling terminal (or to change terminal settings) will
		       result in the command being suspended with the SIGTTIN
		       signal (or SIGTTOU in the case of terminal settings).
		       If this happens when sudo is a foreground process, the
		       command will be granted the controlling terminal	and
		       resumed in the foreground with no user intervention
		       required.  The advantage	of initially running the com-
		       mand in the background is that sudo need	not read from
		       the terminal unless the command explicitly requests it.
		       Otherwise, any terminal input must be passed to the
		       command,	whether	it has required	it or not (the kernel
		       buffers terminals so it is not possible to tell whether
		       the command really wants	the input).  This is different
		       from historic sudo behavior or when the command is not
		       being run in a pty.

		       For this	to work	seamlessly, the	operating system must
		       support the automatic restarting	of system calls.
		       Unfortunately, not all operating	systems	do this	by
		       default,	and even those that do may have	bugs.  For
		       example,	Mac OS X fails to restart the tcgetattr() and
		       tcsetattr() system calls	(this is a bug in Mac OS X).
		       Furthermore, because this behavior depends on the com-
		       mand stopping with the SIGTTIN or SIGTTOU signals, pro-
		       grams that catch	these signals and suspend themselves
		       with a different	signal (usually	SIGTOP)	will not be
		       automatically foregrounded.  Some versions of the linux
		       su(1) command behave this way.  This flag is off	by
		       default.

		       This setting is only supported by version 1.8.7 or
		       higher.	It has no effect unless	I/O logging is enabled
		       or the use_pty flag is enabled.

     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 secu-
		       rity hole as it allows the user to run any arbitrary
		       command as root without logging.	 A safer alternative
		       is to place a colon-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.
		       If the env_reset	flag is	enabled, the EDITOR and/or
		       VISUAL environment variables must be present in the
		       env_keep	list for the env_editor	flag to	function when
		       visudo is invoked via sudo.  This flag is on by
		       default.

     env_reset	       If set, sudo will run the command in a minimal environ-
		       ment containing the TERM, PATH, HOME, MAIL, SHELL,
		       LOGNAME,	USER, USERNAME and SUDO_* variables.  Any
		       variables in the	caller's environment or	in the file
		       specified by the	restricted_env_file option that	match
		       the env_keep and	env_check lists	are then added,	fol-
		       lowed by	any variables present in the file specified by
		       the env_file option (if any).  The contents of the
		       env_keep	and env_check lists, as	modified by global
		       Defaults	parameters in sudoers, are displayed when sudo
		       is run by root with the -V option.  If the secure_path
		       option is set, its value	will be	used for the PATH
		       environment variable.  This flag	is on by default.

     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 some patterns,	especially
		       when the	pattern	references a network file system that
		       is mounted on demand (auto mounted).  The fast_glob
		       option causes sudo to use the fnmatch(3)	function,
		       which does not access the file system to	do its match-
		       ing.  The disadvantage of fast_glob is that it is
		       unable to match relative	path names such	as ./ls	or
		       ../bin/ls.  This	has security implications when path
		       names that include globbing characters are used with
		       the negation operator, `!', as such rules can be	triv-
		       ially bypassed.	As such, this option should not	be
		       used when the sudoers file contains rules that contain
		       negated path names which	include	globbing characters.
		       This flag is off	by default.

     fqdn	       Set this	flag if	you want to put	fully qualified	host
		       names in	the sudoers file when the local	host name (as
		       returned	by the hostname	command) does not contain the
		       domain name.  In	other words, instead of	myhost you
		       would use myhost.mydomain.edu.  You may still use the
		       short form if you wish (and even	mix the	two).  This
		       option is only effective	when the ``canonical'' host
		       name, as	returned by the	getaddrinfo() or
		       gethostbyname() function, is a fully-qualified domain
		       name.  This is usually the case when the	system is con-
		       figured to use DNS for host name	resolution.

		       If the system is	configured to use the /etc/hosts file
		       in preference to	DNS, the ``canonical'' host name may
		       not be fully-qualified.	The order that sources are
		       queried for host	name resolution	is usually specified
		       in the /etc/nsswitch.conf, /etc/netsvc.conf,
		       /etc/host.conf, or, in some cases, /etc/resolv.conf
		       file.  In the /etc/hosts	file, the first	host name of
		       the entry is considered to be the ``canonical'' name;
		       subsequent names	are aliases that are not used by
		       sudoers.	 For example, the following hosts file line
		       for the machine ``xyzzy'' has the fully-qualified
		       domain name as the ``canonical''	host name, and the
		       short version as	an alias.

			     192.168.1.1    xyzzy.sudo.ws xyzzy

		       If the machine's	hosts file entry is not	formatted
		       properly, the fqdn option will not be effective if it
		       is queried before DNS.

		       Beware that when	using DNS for host name	resolution,
		       turning on fqdn requires	sudoers	to make	DNS lookups
		       which renders sudo unusable if DNS stops	working	(for
		       example if the machine is disconnected from the net-
		       work).  Also note that just like	with the hosts file,
		       you must	use the	``canonical'' name as DNS knows	it.
		       That is,	you may	not use	a host alias (CNAME entry) due
		       to performance issues and the fact that there is	no way
		       to get all aliases from DNS.

		       This flag is off	by default.

     ignore_audit_errors
		       Allow commands to be run	even if	sudoers	cannot write
		       to the audit log.  If enabled, an audit log write fail-
		       ure is not treated as a fatal error.  If	disabled, a
		       command may only	be run after the audit event is	suc-
		       cessfully written.  This	flag is	only effective on sys-
		       tems for	which sudoers supports audit logging, includ-
		       ing FreeBSD, Linux, Mac OS X and	Solaris.  This flag is
		       on by default.

     ignore_dot	       If set, sudo will ignore	"." or "" (both	denoting cur-
		       rent directory) in the PATH environment variable; the
		       PATH itself is not modified.  This flag is on by
		       default.

     ignore_iolog_errors
		       Allow commands to be run	even if	sudoers	cannot write
		       to the I/O log.	If enabled, an I/O log write failure
		       is not treated as a fatal error.	 If disabled, the com-
		       mand will be terminated if the I/O log cannot be	writ-
		       ten to.	This flag is off by default.

     ignore_logfile_errors
		       Allow commands to be run	even if	sudoers	cannot write
		       to the log file.	 If enabled, a log file	write failure
		       is not treated as a fatal error.	 If disabled, a	com-
		       mand may	only be	run after the log file entry is	suc-
		       cessfully written.  This	flag only has an effect	when
		       sudoers is configured to	use file-based logging via the
		       logfile option.	This flag is on	by default.

     ignore_local_sudoers
		       If set via LDAP,	parsing	of /usr/local/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.  This	thwarts	the efforts of rogue
		       operators who would attempt to add roles	to
		       /usr/local/etc/sudoers.	When this option is present,
		       /usr/local/etc/sudoers does not even need to exist.
		       Since this option tells sudo how	to behave when no spe-
		       cific LDAP entries have been matched, this sudoOption
		       is only meaningful for the cn=defaults section.	This
		       flag is off by default.

     ignore_unknown_defaults
		       If set, sudo will not produce a warning if it encoun-
		       ters an unknown Defaults	entry in the sudoers file or
		       an unknown sudoOption in	LDAP.  This flag is off	by
		       default.

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

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

     log_input	       If set, sudo will run the command in a pseudo-tty and
		       log all user input.  If the standard input is not con-
		       nected to the user's tty, due to	I/O redirection	or
		       because the command is part of a	pipeline, that input
		       is also captured	and stored in a	separate log file.
		       For more	information, see the I/O LOG FILES section.
		       This flag is off	by default.

     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.  For more	information, see the
		       I/O LOG FILES section.  This flag is off	by default.

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

     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 as pretty as the	default	but
		       some people find	it more	convenient.  This flag is on
		       by default.

     mail_all_cmnds    Send mail to the	mailto user every time a user attempts
		       to run a	command	via sudo (this includes	sudoedit).  No
		       mail will be sent if the	user runs sudo with the	-l or
		       -v option unless	there is an authentication error and
		       the mail_badpass	flag is	also set.  This	flag is	off by
		       default.

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

     mail_badpass      Send mail to the	mailto user if the user	running	sudo
		       does not	enter the correct password.  If	the command
		       the user	is attempting to run is	not permitted by
		       sudoers and one of the mail_all_cmnds, mail_always,
		       mail_no_host, mail_no_perms or mail_no_user flags are
		       set, this flag will have	no effect.  This flag is off
		       by default.

     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.

     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 denied.  This flag is off	by
		       default.

     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.

     match_group_by_gid
		       By default, sudoers will	look up	each group the user is
		       a member	of by group ID to determine the	group name
		       (this is	only done once).  The resulting	list of	the
		       user's group names is used when matching	groups listed
		       in the sudoers file.  This works	well on	systems	where
		       the number of groups listed in the sudoers file is
		       larger than the number of groups	a typical user belongs
		       to.  On systems where group lookups are slow, where
		       users may belong	to a large number of groups, and where
		       the number of groups listed in the sudoers file is rel-
		       atively small, it may be	prohibitively expensive	and
		       running commands	via sudo may take longer than normal.
		       On such systems it may be faster	to use the
		       match_group_by_gid flag to avoid	resolving the user's
		       group IDs to group names.  In this case,	sudoers	must
		       look up any group name listed in	the sudoers file and
		       use the group ID	instead	of the group name when deter-
		       mining whether the user is a member of the group.

		       Note that if match_group_by_gid is enabled, group data-
		       base lookups performed by sudoers will be keyed by
		       group name as opposed to	group ID.  On systems where
		       there are multiple sources for the group	database, it
		       is possible to have conflicting group names or group
		       IDs in the local	/etc/group file	and the	remote group
		       database.  On such systems, enabling or disabling
		       match_group_by_gid can be used to choose	whether	group
		       database	queries	are performed by name (enabled)	or ID
		       (disabled), which may aid in working around group entry
		       conflicts.

		       The match_group_by_gid flag has no effect when sudoers
		       data is stored in LDAP.	This flag is off by default.

		       This setting is only supported by version 1.8.18	or
		       higher.

     netgroup_tuple    If set, netgroup	lookups	will be	performed using	the
		       full netgroup tuple: host name, user name and domain
		       (if one is set).	 Historically, sudo only matched the
		       user name and domain for	netgroups used in a User_List
		       and only	matched	the host name and domain for netgroups
		       used in a Host_List.  This flag is off by default.

     noexec	       If set, all commands run	via sudo will behave as	if the
		       NOEXEC tag has been set,	unless overridden by an	EXEC
		       tag.  See the description of EXEC and NOEXEC above as
		       well as the Preventing shell escapes section at the end
		       of this manual.	This flag is off by default.

     pam_session       On systems that use PAM for authentication, sudo	will
		       create a	new PAM	session	for the	command	to be run in.
		       Disabling pam_session may be needed on older PAM	imple-
		       mentations or on	operating systems where	opening	a PAM
		       session changes the utmp	or wtmp	files.	If PAM session
		       support is disabled, resource limits may	not be updated
		       for the command being run.  If pam_session,
		       pam_setcred, and	use_pty	are disabled and I/O logging
		       has not been configured,	sudo will execute the command
		       directly	instead	of running it as a child process.
		       This flag is on by default.

		       This setting is only supported by version 1.8.7 or
		       higher.

     pam_setcred       On systems that use PAM for authentication, sudo	will
		       attempt to establish credentials	for the	target user by
		       default,	if supported by	the underlying authentication
		       system.	One example of a credential is a Kerberos
		       ticket.	If pam_session,	pam_setcred, and use_pty are
		       disabled	and I/O	logging	has not	been configured, sudo
		       will execute the	command	directly instead of running it
		       as a child process.  This flag is on by default.

		       This setting is only supported by version 1.8.8 or
		       higher.

     passprompt_override
		       The password prompt specified by	passprompt will	nor-
		       mally only be used if the password prompt provided by
		       systems such as PAM matches the string ``Password:''.
		       If passprompt_override is set, passprompt will always
		       be used.	 This flag is off by default.

     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 the location of executables that
		       the normal user does not	have access to.	 The disadvan-
		       tage is that if 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.

     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 vec-
		       tor is left unaltered.  The real	and effective group
		       IDs, however, are still set to match the	target user.
		       This flag is off	by default.

     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	them that sudo has hung	at
		       this point.  When pwfeedback is set, sudo will provide
		       visual feedback when 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.

     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 scripts.  This flag is off	by
		       default.

     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 turning off root_sudo
		       will also prevent root from running sudoedit.  Dis-
		       abling root_sudo	provides no real additional security;
		       it exists purely	for historical reasons.	 This flag is
		       on by default.

     rootpw	       If set, sudo will prompt	for the	root password instead
		       of the password of the invoking user when running a
		       command or editing a file.  This	flag is	off by
		       default.

     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 when run-
		       ning a command or editing a file.  This flag is off by
		       default.

     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 effectively makes the -s
		       option imply -H.	 Note that HOME	is already set when
		       the env_reset option 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.

     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 (including the RCS revision control
		       system) use LOGNAME to determine	the real identity of
		       the user, it may	be desirable to	change this behavior.
		       This can	be done	by negating the	set_logname option.
		       Note that set_logname will have no effect if the
		       env_reset option	has not	been disabled and the env_keep
		       list contains LOGNAME, USER or USERNAME.	 This flag is
		       on by default.

     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 enabled.  By default, the new
		       entry will be a copy of the user's existing utmp	entry
		       (if any), with the tty, time, type and pid fields
		       updated.	 This flag is on by default.

     setenv	       Allow the user to disable the env_reset option from the
		       command line via	the -E option.	Additionally, environ-
		       ment variables set via the command line are not subject
		       to the restrictions imposed by env_check, env_delete,
		       or env_keep.  As	such, only trusted users should	be
		       allowed to set variables	in this	manner.	 This flag is
		       off by default.

     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 it is set, falling back on the
		       shell listed in the invoking user's /etc/passwd entry
		       if not).	 This flag is off by default.

     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 invoking user's UID.	 In
		       other words, this makes sudo act	as a setuid wrapper.
		       This can	be useful on systems that disable some poten-
		       tially dangerous	functionality when a program is	run
		       setuid.	This option is only effective on systems that
		       support either the setreuid(2) or setresuid(2) system
		       call.  This flag	is off by default.

     sudoedit_checkdir
		       If set, sudoedit	will check all directory components of
		       the path	to be edited for writability by	the invoking
		       user.  Symbolic links will not be followed in writable
		       directories and sudoedit	will refuse to edit a file
		       located in a writable directory.	 These restrictions
		       are not enforced	when sudoedit is run by	root.  On some
		       systems,	if all directory components of the path	to be
		       edited are not readable by the target user, sudoedit
		       will be unable to edit the file.	 This flag is on by
		       default.

		       This setting was	first introduced in version 1.8.15 but
		       initially suffered from a race condition.  The check
		       for symbolic links in writable intermediate directories
		       was added in version 1.8.16.

     sudoedit_follow   By default, sudoedit will not follow symbolic links
		       when opening files.  The	sudoedit_follow	option can be
		       enabled to allow	sudoedit to open symbolic links.  It
		       may be overridden on a per-command basis	by the FOLLOW
		       and NOFOLLOW tags.  This	flag is	off by default.

		       This setting is only supported by version 1.8.15	or
		       higher.

     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 when running a
		       command or editing a file.  Note	that this flag pre-
		       cludes the use of a uid not listed in the passwd	data-
		       base as an argument to the -u option.  This flag	is off
		       by default.

     tty_tickets       If set, users must authenticate on a per-tty basis.
		       With this flag enabled, sudo will use a separate	record
		       in the time stamp file for each tty.  If	disabled, a
		       single record is	used for all login sessions.  This
		       flag is on by default.

     umask_override    If set, sudo will set the umask as specified in the
		       sudoers file without modification.  This	makes it pos-
		       sible to	specify	a umask	in the sudoers file that is
		       more permissive than the	user's own umask and matches
		       historical behavior.  If	umask_override is not set,
		       sudo will set the umask to be the union of the user's
		       umask and what is specified in sudoers.	This flag is
		       off by default.

     use_loginclass    If set, sudo will apply the defaults specified for the
		       target user's login class if one	exists.	 Only avail-
		       able if sudo is configured with the --with-logincap
		       option.	This flag is off by default.

     use_netgroups     If set, netgroups (prefixed with	`+'), may be used in
		       place of	a user or host.	 For LDAP-based	sudoers, net-
		       group support requires an expensive substring match on
		       the server unless the NETGROUP_BASE directive is
		       present in the /etc/ldap.conf file.  If netgroups are
		       not needed, this	option can be disabled to reduce the
		       load on the LDAP	server.	 This flag is on by default.

     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 user's terminal device
		       after the main program has finished executing.  Use of
		       this option will	make that impossible.  This flag is
		       off by default.

     user_command_timeouts
		       If set, the user	may specify a timeout on the command
		       line.  If the timeout expires before the	command	has
		       exited, the command will	be terminated.	If a timeout
		       is specified both in the	sudoers	file and on the	com-
		       mand line, the smaller of the two timeouts will be
		       used.  See the Timeout_Spec section for a description
		       of the timeout syntax.  This flag is off	by default.

		       This setting is only supported by version 1.8.20	or
		       higher.

     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.

     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 password even when it would be	visi-
		       ble on the screen.  This	makes it possible to run
		       things like ``ssh somehost sudo ls'' since by default,
		       ssh(1) does not allocate	a tty when running a command.
		       This flag is off	by default.

     Integers:

     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	be used	to specify a different
		       file descriptor at which	to start closing.  The default
		       is 3.

     command_timeout   The maximum amount of time a command is allowed to run
		       before it is terminated.	 See the Timeout_Spec section
		       for a description of the	timeout	syntax.

		       This setting is only supported by version 1.8.20	or
		       higher.

     maxseq	       The maximum sequence number that	will be	substituted
		       for the ``%{seq}'' escape in the	I/O log	file (see the
		       iolog_dir description above for more information).
		       While the value substituted for ``%{seq}'' is in	base
		       36, maxseq itself should	be expressed in	decimal.  Val-
		       ues larger than 2176782336 (which corresponds to	the
		       base 36 sequence	number ``ZZZZZZ'') will	be silently
		       truncated to 2176782336.	 The default value is
		       2176782336.

		       Once the	local sequence number reaches the value	of
		       maxseq, it will ``roll over'' to	zero, after which
		       sudoers will truncate and re-use	any existing I/O log
		       path names.

		       This setting is only supported by version 1.8.7 or
		       higher.

     passwd_tries      The number of tries a user gets to enter	his/her	pass-
		       word before sudo	logs the failure and exits.  The
		       default is 3.

     syslog_maxlen     On many systems,	syslog(3) has a	relatively small log
		       buffer.	IETF RFC 5424 states that syslog servers must
		       support messages	of at least 480	bytes and should sup-
		       port messages up	to 2048	bytes.	By default, sudoers
		       creates log messages up to 980 bytes which corresponds
		       to the historic BSD syslog implementation which used a
		       1024 byte buffer	to store the message, date, hostname
		       and program name.  To prevent syslog messages from
		       being truncated,	sudoers	will split up log messages
		       that are	larger than syslog_maxlen bytes.  When a mes-
		       sage is split, additional parts will include the	string
		       ``(command continued)'' after the user name and before
		       the continued command line arguments.

		       This setting is only supported by version 1.8.19	or
		       higher.

     Integers that can be used in a boolean context:

     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 default is 80 (use 0 or negate
		       the option to disable word wrap).

     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 insuffi-
		       cient, for example 2.5.	The default is 5.

     timestamp_timeout
		       Number of minutes that can elapse before	sudo will ask
		       for a passwd again.  The	timeout	may include a frac-
		       tional component	if minute granularity is insufficient,
		       for example 2.5.	 The default is	5.  Set	this to	0 to
		       always prompt for a password.  If set to	a value	less
		       than 0 the user's time stamp will not expire until the
		       system is rebooted.  This can be	used to	allow users to
		       create or delete	their own time stamps via ``sudo -v''
		       and ``sudo -k'' respectively.

     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 of the umask option, which
		       defaults	to 0022.  This guarantees that sudo never low-
		       ers the umask when 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.

     Strings:

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

     editor	       A colon (`:') separated list of editors allowed to be
		       used with visudo.  visudo will choose the editor	that
		       matches the user's EDITOR or VISUAL environment vari-
		       able if possible, or the	first editor in	the list that
		       exists and is executable.  Note that the	EDITOR and
		       VISUAL environment variables are	not preserved by
		       default when the	env_reset option is enabled.  The
		       default is vi.

     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	LOG_OUTPUT tags	are present
		       for a command.  The session sequence number, if any, is
		       stored in the directory.	 The default is
		       /var/log/sudo-io.

		       The following percent (`%') escape sequences are	sup-
		       ported:

		       %{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	com-
			     mand will be run as (e.g. root)

		       %{runas_group}
			     expanded to the group name	of the user the	com-
			     mand 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 sys-
		       tem's strftime(3) function will be expanded.

		       To include a literal `%'	character, the string `%%'
		       should be used.

     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 command.	Note that iolog_file
		       may contain directory components.  The default is
		       ``%{seq}''.

		       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(3) function.

		       If the path created by concatenating iolog_dir and
		       iolog_file already exists, the existing I/O log file
		       will be truncated and overwritten unless	iolog_file
		       ends in six or more Xs.

     iolog_flush       If set, sudo will flush I/O log data to disk after each
		       write instead of	buffering it.  This makes it possible
		       to view the logs	in real-time as	the program is execut-
		       ing but may significantly reduce	the effectiveness of
		       I/O log compression.  This flag is off by default.

		       This setting is only supported by version 1.8.20	or
		       higher.

     iolog_group       The group name to look up when setting the group	ID on
		       new I/O log files and directories.  If iolog_group is
		       not set,	the primary group ID of	the user specified by
		       iolog_user is used.  If neither iolog_group nor
		       iolog_user are set, I/O log files and directories are
		       created with group ID 0.

		       This setting is only supported by version 1.8.19	or
		       higher.

     iolog_mode	       The file	mode to	use when creating I/O log files.  Mode
		       bits for	read and write permissions for owner, group or
		       other are honored, everything else is ignored.  The
		       file permissions	will always include the	owner read and
		       write bits, even	if they	are not	present	in the speci-
		       fied mode.  When	creating I/O log directories, search
		       (execute) bits are added	to to match the	read and write
		       bits specified by iolog_mode.  Defaults to 0600 (read
		       and write by user only).

		       This setting is only supported by version 1.8.19	or
		       higher.

     iolog_user	       The user	name to	look up	when setting the user and
		       group IDs on new	I/O log	files and directories.	If
		       iolog_group is set, it will be used instead of the
		       user's primary group ID.	 By default, I/O log files and
		       directories are created with user and group ID 0.

		       This setting can	be useful when the I/O logs are	stored
		       on a Network File System	(NFS) share.  Having a dedi-
		       cated user own the I/O log files	means that sudoers
		       does not	write to the log files as user ID 0, which is
		       usually not permitted by	NFS.

		       This setting is only supported by version 1.8.19	or
		       higher.

     lecture_status_dir
		       The directory in	which sudo stores per-user lecture
		       status files.  Once a user has received the lecture, a
		       zero-length file	is created in this directory so	that
		       sudo will not lecture the user again.  This directory
		       should not be cleared when the system reboots.  The
		       default is /var/db/sudo/lectured.

     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 ***''.

     noexec_file       As of sudo version 1.8.1	this option is no longer sup-
		       ported.	The path to the	noexec file should now be set
		       in the sudo.conf(5) file.

     pam_login_service
		       On systems that use PAM for authentication, this	is the
		       service name used when the -i option is specified.  The
		       default value is	``sudo''.  See the description of
		       pam_service for more information.

		       This setting is only supported by version 1.8.8 or
		       higher.

     pam_service       On systems that use PAM for authentication, the service
		       name specifies the PAM policy to	apply.	This usually
		       corresponds to an entry in the pam.conf file or a file
		       in the /etc/pam.d directory.  The default value is
		       ``sudo''.

		       This setting is only supported by version 1.8.8 or
		       higher.

     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 supported:

		       %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	com-
			     mand 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:''.

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

     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''.

     timestampdir      The directory in	which sudo stores its time stamp
		       files.  This directory should be	cleared	when the sys-
		       tem reboots.  The default is /var/run/sudo/ts.

     timestampowner    The owner of the	lecture	status directory, time stamp
		       directory and all files stored therein.	The default is
		       root.

     Strings that can be used in a boolean context:

     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 form ``VARIABLE=value'' or	``export
		   VARIABLE=value''.  The value	may optionally be surrounded
		   by single or	double quotes.	Variables in this file are
		   only	added if the variable does not already exist in	the
		   environment.	 This file is considered to be part of the
		   security policy, its	contents are not subject to other sudo
		   environment restrictions such as env_keep and env_check.

     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.

     fdexec	   Determines whether sudo will	execute	a command by its path
		   or by an open file descriptor.  It has the following	possi-
		   ble values:

		   always  Always execute by file descriptor.

		   never   Never execute by file descriptor.

		   digest_only
			   Only	execute	by file	descriptor if the command has
			   an associated digest	in the sudoers file.

		   The default value is	digest_only.  This avoids a time of
		   check versus	time of	use race condition when	the command is
		   located in a	directory writable by the invoking user.

		   Note	that fdexec will change	the first element of the argu-
		   ment	vector for scripts ($0 in the shell) due to the	way
		   the kernel runs script interpreters.	 Instead of being a
		   normal path,	it will	refer to a file	descriptor.  For exam-
		   ple,	/dev/fd/4 on Solaris and /proc/self/fd/4 on Linux.  A
		   workaround is to use	the SUDO_COMMAND environment variable
		   instead.

		   The fdexec setting is only used when	the command is matched
		   by path name.  It has no effect if the command is matched
		   by the built-in ALL alias.

		   This	setting	is only	supported by version 1.8.20 or higher.
		   If the operating system does	not support the	fexecve(2)
		   system call,	this setting has no effect.

     group_plugin  A string containing a sudoers group plugin with optional
		   arguments.  The string should consist of the	plugin path,
		   either fully-qualified or relative to the
		   /usr/local/libexec/sudo directory, followed by any configu-
		   ration arguments the	plugin requires.  These	arguments (if
		   any)	will be	passed to the plugin's initialization func-
		   tion.  If arguments are present, the	string must be
		   enclosed in double quotes ("").

		   For more information	see GROUP PROVIDER PLUGINS.

     lecture	   This	option controls	when a short lecture will be printed
		   along with the password prompt.  It has the following pos-
		   sible 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.

     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.

     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 file entries for the cur-
			     rent 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	file 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.

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

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

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

     mailfrom	   Address to use for the ``from'' address when	sending	warn-
		   ing and error mail.	The address should be enclosed in dou-
		   ble quotes ("") to protect against sudo interpreting	the @
		   sign.  Defaults to the name of the user running sudo.

     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.

     restricted_env_file
		   The restricted_env_file option specifies the	fully quali-
		   fied	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 form	``VARIABLE=value'' or ``export
		   VARIABLE=value''.  The value	may optionally be surrounded
		   by single or	double quotes.	Variables in this file are
		   only	added if the variable does not already exist in	the
		   environment.	 Unlike	env_file, the file's contents are not
		   trusted and are processed in	a manner similar to that of
		   the invoking	user's environment.  If	env_reset is enabled,
		   variables in	the file will only be added if they are
		   matched by either the env_check or env_keep list.  If
		   env_reset is	disabled, variables in the file	are added as
		   long	as they	are not	matched	by the env_delete list.	 In
		   either case,	the contents of	restricted_env_file are	pro-
		   cessed before the contents of env_file.

     secure_path   Path	used for every command run from	sudo.  If you don't
		   trust the people running sudo to have a sane	PATH environ-
		   ment	variable you may want to use this.  Another use	is if
		   you want to have the	``root path'' be separate from the
		   ``user path''.  Users in the	group specified	by the
		   exempt_group	option are not affected	by secure_path.	 This
		   option is not set by	default.

     syslog	   Syslog facility if syslog is	being used for logging (negate
		   to disable syslog logging).	Defaults to authpriv.

		   The following syslog	facilities are supported: authpriv (if
		   your	OS supports it), auth, daemon, user, local0, local1,
		   local2, local3, local4, local5, local6, and local7.

     syslog_badpri
		   Syslog priority to use when the user	is not allowed to run
		   a command or	when authentication is unsuccessful.  Defaults
		   to alert.

		   The following syslog	priorities are supported: alert, crit,
		   debug, emerg, err, info, notice, warning, and none.	Negat-
		   ing the option or setting it	to a value of none will	dis-
		   able	logging	of unsuccessful	commands.

     syslog_goodpri
		   Syslog priority to use when the user	is allowed to run a
		   command and authentication is successful.  Defaults to
		   notice.

		   See syslog_badpri for the list of supported syslog priori-
		   ties.  Negating the option or setting it to a value of none
		   will	disable	logging	of successful commands.

     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 file 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 file 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.

     Lists that	can be used in a boolean context:

     env_check	       Environment variables to	be removed from	the user's
		       environment unless they are considered ``safe''.	 For
		       all variables except TZ,	``safe'' means that the	vari-
		       able's value does not contain any `%' or	`/' charac-
		       ters.  This can be used to guard	against	printf-style
		       format vulnerabilities in poorly-written	programs.  The
		       TZ variable is considered unsafe	if any of the follow-
		       ing are true:

		       +o   It consists of a fully-qualified path name, option-
			   ally	prefixed with a	colon (`:'), that does not
			   match the location of the zoneinfo directory.

		       +o   It contains a .. path element.

		       +o   It contains white space or non-printable charac-
			   ters.

		       +o   It is longer	than the value of PATH_MAX.

		       The argument may	be a double-quoted, space-separated
		       list or a single	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 enabled
		       or disabled, variables specified	by env_check will be
		       preserved in the	environment if they pass the aforemen-
		       tioned check.  The global list of environment variables
		       to check	is displayed when sudo is run by root with the
		       -V option.

     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 without double-quotes.  The list
		       can be replaced,	added to, deleted from,	or disabled by
		       using the =, +=,	-=, and	! operators respectively.  The
		       global list of environment variables to remove is dis-
		       played when sudo	is run by root with the	-V option.
		       Note that many operating	systems	will remove poten-
		       tially dangerous	variables from the environment of any
		       setuid process (such as sudo).

     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 receive.  The argument may
		       be a double-quoted, space-separated list	or a single
		       value without double-quotes.  The list can be replaced,
		       added to, deleted from, or disabled by using the	=, +=,
		       -=, and ! operators respectively.  The global list of
		       variables to keep is displayed when sudo	is run by root
		       with the	-V option.

GROUP PROVIDER PLUGINS
     The sudoers plugin	supports its own plugin	interface to allow non-Unix
     group lookups which can query a group source other	than the standard Unix
     group database.  This can be used to implement support for	the
     nonunix_group syntax described earlier.

     Group provider plugins are	specified via the group_plugin Defaults	set-
     ting.  The	argument to group_plugin should	consist	of the plugin path,
     either fully-qualified or relative	to the /usr/local/libexec/sudo direc-
     tory, followed by any configuration options the plugin requires.  These
     options (if specified) will be passed to the plugin's initialization
     function.	If options are present,	the string must	be enclosed in double
     quotes ("").

     The following group provider plugins are installed	by default:

     group_file
	       The group_file plugin supports an alternate group file that
	       uses the	same syntax as the /etc/group file.  The path to the
	       group file should be specified as an option to the plugin.  For
	       example,	if the group file to be	used is	/etc/sudo-group:

	       Defaults	group_plugin="group_file.so /etc/sudo-group"

     system_group
	       The system_group	plugin supports	group lookups via the standard
	       C library functions getgrnam() and getgrid().  This plugin can
	       be used in instances where the user belongs to groups not
	       present in the user's supplemental group	vector.	 This plugin
	       takes no	options:

	       Defaults	group_plugin=system_group.so

     The group provider	plugin API is described	in detail in sudo_plugin(8).

LOG FORMAT
     sudoers can log events using either syslog(3) or a	simple log file.  The
     log format	is almost identical in both cases.

   Accepted command log	entries
     Commands that sudo	runs are logged	using the following format (split into
     multiple lines for	readability):

	 date hostname progname: username : TTY=ttyname	; PWD=cwd ; \
	     USER=runasuser ; GROUP=runasgroup ; TSID=logid ; \
	     ENV=env_vars COMMAND=command

     Where the fields are as follows:

     date	   The date the	command	was run.  Typically, this is in	the
		   format ``MMM, DD, HH:MM:SS''.  If logging via syslog(3),
		   the actual date format is controlled	by the syslog daemon.
		   If logging to a file	and the	log_year option	is enabled,
		   the date will also include the year.

     hostname	   The name of the host	sudo was run on.  This field is	only
		   present when	logging	via syslog(3).

     progname	   The name of the program, usually sudo or sudoedit.  This
		   field is only present when logging via syslog(3).

     username	   The login name of the user who ran sudo.

     ttyname	   The short name of the terminal (e.g.	``console'',
		   ``tty01'', or ``pts/0'') sudo was run on, or	``unknown'' if
		   there was no	terminal present.

     cwd	   The current working directory that sudo was run in.

     runasuser	   The user the	command	was run	as.

     runasgroup	   The group the command was run as if one was specified on
		   the command line.

     logid	   An I/O log identifier that can be used to replay the	com-
		   mand's output.  This	is only	present	when the log_input or
		   log_output option is	enabled.

     env_vars	   A list of environment variables specified on	the command
		   line, if specified.

     command	   The actual command that was executed.

     Messages are logged using the locale specified by sudoers_locale, which
     defaults to the ``C'' locale.

   Denied command log entries
     If	the user is not	allowed	to run the command, the	reason for the denial
     will follow the user name.	 Possible reasons include:

     user NOT in sudoers
       The user	is not listed in the sudoers file.

     user NOT authorized on host
       The user	is listed in the sudoers file but is not allowed to run	com-
       mands on	the host.

     command not allowed
       The user	is listed in the sudoers file for the host but they are	not
       allowed to run the specified command.

     3 incorrect password attempts
       The user	failed to enter	their password after 3 tries.  The actual num-
       ber of tries will vary based on the number of failed attempts and the
       value of	the passwd_tries option.

     a password	is required
       sudo's -n option	was specified but a password was required.

     sorry, you	are not	allowed	to set the following environment variables
       The user	specified environment variables	on the command line that were
       not allowed by sudoers.

   Error log entries
     If	an error occurs, sudoers will log a message and, in most cases,	send a
     message to	the administrator via email.  Possible errors include:

     parse error in /usr/local/etc/sudoers near	line N
       sudoers encountered an error when parsing the specified file.  In some
       cases, the actual error may be one line above or	below the line number
       listed, depending on the	type of	error.

     problem with defaults entries
       The sudoers file	contains one or	more unknown Defaults settings.	 This
       does not	prevent	sudo from running, but the sudoers file	should be
       checked using visudo.

     timestamp owner (username): No such user
       The time	stamp directory	owner, as specified by the timestampowner set-
       ting, could not be found	in the password	database.

     unable to open/read /usr/local/etc/sudoers
       The sudoers file	could not be opened for	reading.  This can happen when
       the sudoers file	is located on a	remote file system that	maps user ID 0
       to a different value.  Normally,	sudoers	tries to open the sudoers file
       using group permissions to avoid	this problem.  Consider	either chang-
       ing the ownership of /usr/local/etc/sudoers or adding an	argument like
       ``sudoers_uid=N'' (where	`N' is the user	ID that	owns the sudoers file)
       to the end of the sudoers Plugin	line in	the sudo.conf(5) file.

     unable to stat /usr/local/etc/sudoers
       The /usr/local/etc/sudoers file is missing.

     /usr/local/etc/sudoers is not a regular file
       The /usr/local/etc/sudoers file exists but is not a regular file	or
       symbolic	link.

     /usr/local/etc/sudoers is owned by	uid N, should be 0
       The sudoers file	has the	wrong owner.  If you wish to change the
       sudoers file owner, please add ``sudoers_uid=N''	(where `N' is the user
       ID that owns the	sudoers	file) to the sudoers Plugin line in the
       sudo.conf(5) file.

     /usr/local/etc/sudoers is world writable
       The permissions on the sudoers file allow all users to write to it.
       The sudoers file	must not be world-writable, the	default	file mode is
       0440 (readable by owner and group, writable by none).  The default mode
       may be changed via the ``sudoers_mode'' option to the sudoers Plugin
       line in the sudo.conf(5)	file.

     /usr/local/etc/sudoers is owned by	gid N, should be 1
       The sudoers file	has the	wrong group ownership.	If you wish to change
       the sudoers file	group ownership, please	add ``sudoers_gid=N'' (where
       `N' is the group	ID that	owns the sudoers file) to the sudoers Plugin
       line in the sudo.conf(5)	file.

     unable to open /var/run/sudo/ts/username
       sudoers was unable to read or create the	user's time stamp file.	 This
       can happen when timestampowner is set to	a user other than root and the
       mode on /var/run/sudo is	not searchable by group	or other.  The default
       mode for	/var/run/sudo is 0711.

     unable to write to	/var/run/sudo/ts/username
       sudoers was unable to write to the user's time stamp file.

     /var/run/sudo/ts is owned by uid X, should	be Y
       The time	stamp directory	is owned by a user other than timestampowner.
       This can	occur when the value of	timestampowner has been	changed.
       sudoers will ignore the time stamp directory until the owner is cor-
       rected.

     /var/run/sudo/ts is group writable
       The time	stamp directory	is group-writable; it should be	writable only
       by timestampowner.  The default mode for	the time stamp directory is
       0700.  sudoers will ignore the time stamp directory until the mode is
       corrected.

   Notes on logging via	syslog
     By	default, sudoers logs messages via syslog(3).  The date, hostname, and
     progname fields are added by the system's syslog()	function, not sudoers
     itself.  As such, they may	vary in	format on different systems.

     The maximum size of syslog	messages varies	from system to system.	The
     syslog_maxlen setting can be used to change the maximum syslog message
     size from the default value of 980	bytes.	For more information, see the
     description of syslog_maxlen.

   Notes on logging to a file
     If	the logfile option is set, sudoers will	log to a local file, such as
     /var/log/sudo.  When logging to a file, sudoers uses a format similar to
     syslog(3),	with a few important differences:

     1.	  The progname and hostname fields are not present.

     2.	  If the log_year option is enabled, the date will also	include	the
	  year.

     3.	  Lines	that are longer	than loglinelen	characters (80 by default) are
	  word-wrapped and continued on	the next line with a four character
	  indent.  This	makes entries easier to	read for a human being,	but
	  makes	it more	difficult to use grep(1) on the	log files.  If the
	  loglinelen option is set to 0	(or negated with a `!'), word wrap
	  will be disabled.

I/O LOG	FILES
     When I/O logging is enabled, sudo will run	the command in a pseudo-tty
     and log all user input and/or output.  I/O	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 sudo log	line, prefixed with
     ``TSID=''.	 The iolog_file	option may be used to control the format of
     the session ID.

     Each I/O log is stored in a separate directory that contains the follow-
     ing files:

     log       a text file containing the time the command was run, the	name
	       of the user who ran sudo, the name of the target	user, the name
	       of the target group (optional), the terminal that sudo was run
	       from, the number	of rows	and columns of the terminal, the work-
	       ing directory the command was run from and the path name	of the
	       command itself (with arguments if present)

     timing    a log of	the amount of time between, and	the number of bytes
	       in, each	I/O log	entry (used for	session	playback)

     ttyin     input from the user's tty (what the user	types)

     stdin     input from a pipe or file

     ttyout    output from the pseudo-tty (what	the command writes to the
	       screen)

     stdout    standard	output to a pipe or redirected to a file

     stderr    standard	error to a pipe	or redirected to a file

     All files other than log are compressed in	gzip format unless the
     compress_io flag has been disabled.  Due to buffering, it is not normally
     possible to display the I/O logs in real-time as the program is executing
     The I/O log data will not be complete until the program run by sudo has
     exited or has been	terminated by a	signal.	 The iolog_flush flag can be
     used to disable buffering,	in which case I/O log data is written to disk
     as	soon as	it is available.  The output portion of	an I/O log file	can be
     viewed with the sudoreplay(8) utility, which can also be used to list or
     search the	available logs.

     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 command output via
     log_output	or LOG_OUTPUT is all that is required.

     Since each	session's I/O logs are stored in a separate directory, tradi-
     tional log	rotation utilities cannot be used to limit the number of I/O
     logs.  The	simplest way to	limit the number of I/O	is by setting the
     maxseq option to the maximum number of logs you wish to store.  Once the
     I/O log sequence number reaches maxseq, it	will be	reset to zero and
     sudoers will truncate and re-use any existing I/O logs.

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

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

     /etc/group		       Local groups file

     /etc/netgroup	       List of network groups

     /var/log/sudo-io	       I/O log files

     /var/run/sudo/ts	       Directory containing time stamps	for the
			       sudoers security	policy

     /var/db/sudo/lectured     Directory containing lecture status files for
			       the sudoers security policy

     /etc/environment	       Initial environment for -i mode on AIX and
			       Linux systems

EXAMPLES
     Below are example sudoers file entries.  Admittedly, some of these	are a
     bit contrived.  First, we allow a few environment variables to pass and
     then define our aliases:

     # Run X applications through sudo;	HOME is	used to	find the
     # .Xauthority file.  Note that other programs use HOME to find
     # configuration files and this may	lead to	privilege escalation!
     Defaults env_keep += "DISPLAY HOME"

     # User alias specification
     User_Alias	     FULLTIMERS	= millert, mikef, dowdy
     User_Alias	     PARTTIMERS	= bostley, jwfox, crawl
     User_Alias	     WEBMASTERS	= will,	wendy, wim

     # Runas alias specification
     Runas_Alias     OP	= root,	operator
     Runas_Alias     DB	= oracle, sybase
     Runas_Alias     ADMINGRP =	adm, oper

     # Host alias specification
     Host_Alias	     SPARC = bigtime, eclipse, moet, anchor :\
		     SGI = grolsch, dandelion, black :\
		     ALPHA = widget, thalamus, foobar :\
		     HPPA = boa, nag, python
     Host_Alias	     CUNETS = 128.138.0.0/255.255.0.0
     Host_Alias	     CSNETS = 128.138.243.0, 128.138.204.0/24, 128.138.242.0
     Host_Alias	     SERVERS = master, mail, www, ns
     Host_Alias	     CDROM = orion, perseus, hercules

     # Cmnd alias specification
     Cmnd_Alias	     DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
			     /usr/sbin/restore,	/usr/sbin/rrestore,\
			     sha224:0GomF8mNN3wlDt1HD9XldjJ3SNgpFdbjO1+NsQ== \
			     /home/operator/bin/start_backups
     Cmnd_Alias	     KILL = /usr/bin/kill
     Cmnd_Alias	     PRINTING =	/usr/sbin/lpc, /usr/bin/lprm
     Cmnd_Alias	     SHUTDOWN =	/usr/sbin/shutdown
     Cmnd_Alias	     HALT = /usr/sbin/halt
     Cmnd_Alias	     REBOOT = /usr/sbin/reboot
     Cmnd_Alias	     SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh,\
			      /usr/local/bin/tcsh, /usr/bin/rsh,\
			      /usr/local/bin/zsh
     Cmnd_Alias	     SU	= /usr/bin/su
     Cmnd_Alias	     PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less

     Here we override some of the compiled in default values.  We want sudo to
     log via syslog(3) using the auth facility in all cases.  We don't want to
     subject the full time staff to the	sudo lecture, user millert need	not
     give a password, and we don't want	to reset the LOGNAME, USER or USERNAME
     environment variables when	running	commands as root.  Additionally, on
     the machines in the SERVERS Host_Alias, we	keep an	additional local log
     file and make sure	we log the year	in each	log line since the log entries
     will be kept around for several years.  Lastly, we	disable	shell escapes
     for the commands in the PAGERS Cmnd_Alias (/usr/bin/more, /usr/bin/pg and
     /usr/bin/less).  Note that	this will not effectively constrain users with
     sudo ALL privileges.

     # Override	built-in defaults
     Defaults		     syslog=auth
     Defaults>root	     !set_logname
     Defaults:FULLTIMERS     !lecture
     Defaults:millert	     !authenticate
     Defaults@SERVERS	     log_year, logfile=/var/log/sudo.log
     Defaults!PAGERS	     noexec

     The User specification is the part	that actually determines who may run
     what.

     root	     ALL = (ALL) ALL
     %wheel	     ALL = (ALL) ALL

     We	let root and any user in group wheel run any command on	any host as
     any user.

     FULLTIMERS	     ALL = NOPASSWD: ALL

     Full time sysadmins (millert, mikef, and dowdy) may run any command on
     any host without authenticating themselves.

     PARTTIMERS	     ALL = ALL

     Part time sysadmins bostley, jwfox, and crawl) may	run any	command	on any
     host but they must	authenticate themselves	first (since the entry lacks
     the NOPASSWD tag).

     jack	     CSNETS = ALL

     The user jack may run any command on the machines in the CSNETS alias
     (the networks 128.138.243.0, 128.138.204.0, and 128.138.242.0).  Of those
     networks, only 128.138.204.0 has an explicit netmask (in CIDR notation)
     indicating	it is a	class C	network.  For the other	networks in CSNETS,
     the local machine's netmask will be used during matching.

     lisa	     CUNETS = ALL

     The user lisa may run any command on any host in the CUNETS alias (the
     class B network 128.138.0.0).

     operator	     ALL = DUMPS, KILL,	SHUTDOWN, HALT,	REBOOT,	PRINTING,\
		     sudoedit /etc/printcap, /usr/oper/bin/

     The operator user may run commands	limited	to simple maintenance.	Here,
     those are commands	related	to backups, killing processes, the printing
     system, shutting down the system, and any commands	in the directory
     /usr/oper/bin/.  Note that	one command in the DUMPS Cmnd_Alias includes a
     sha224 digest, /home/operator/bin/start_backups.  This is because the
     directory containing the script is	writable by the	operator user.	If the
     script is modified	(resulting in a	digest mismatch) it will no longer be
     possible to run it	via sudo.

     joe	     ALL = /usr/bin/su operator

     The user joe may only su(1) to operator.

     pete	     HPPA = /usr/bin/passwd [A-Za-z]*, !/usr/bin/passwd	*root*

     %opers	     ALL = (: ADMINGRP)	/usr/sbin/

     Users in the opers	group may run commands in /usr/sbin/ as	themselves
     with any group in the ADMINGRP Runas_Alias	(the adm and oper groups).

     The user pete is allowed to change	anyone's password except for root on
     the HPPA machines.	 Because command line arguments	are matched as a sin-
     gle, concatenated string, the `*' wildcard	will match multiple words.
     This example assumes that passwd(1) does not take multiple	user names on
     the command line.	Note that on GNU systems, options to passwd(1) may be
     specified after the user argument.	 As a result, this rule	will also
     allow:

	 passwd	username --expire

     which may not be desirable.

     bob	     SPARC = (OP) ALL :	SGI = (OP) ALL

     The user bob may run anything on the SPARC	and SGI	machines as any	user
     listed in the OP Runas_Alias (root	and operator.)

     jim	     +biglab = ALL

     The user jim may run any command on machines in the biglab	netgroup.
     sudo knows	that ``biglab''	is a netgroup due to the `+' prefix.

     +secretaries    ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser

     Users in the secretaries netgroup need to help manage the printers	as
     well as add and remove users, so they are allowed to run those commands
     on	all machines.

     fred	     ALL = (DB)	NOPASSWD: ALL

     The user fred can run commands as any user	in the DB Runas_Alias (oracle
     or	sybase)	without	giving a password.

     john	     ALPHA = /usr/bin/su [!-]*,	!/usr/bin/su *root*

     On	the ALPHA machines, user john may su to	anyone except root but he is
     not allowed to specify any	options	to the su(1) command.

     jen	     ALL, !SERVERS = ALL

     The user jen may run any command on any machine except for	those in the
     SERVERS Host_Alias	(master, mail, www and ns).

     jill	     SERVERS = /usr/bin/, !SU, !SHELLS

     For any machine in	the SERVERS Host_Alias,	jill may run any commands in
     the directory /usr/bin/ except for	those commands belonging to the	SU and
     SHELLS Cmnd_Aliases.  While not specifically mentioned in the rule, the
     commands in the PAGERS Cmnd_Alias all reside in /usr/bin and have the
     noexec option set.

     steve	     CSNETS = (operator) /usr/local/op_commands/

     The user steve may	run any	command	in the directory /usr/local/op_com-
     mands/ but	only as	user operator.

     matt	     valkyrie =	KILL

     On	his personal workstation, valkyrie, matt needs to be able to kill hung
     processes.

     WEBMASTERS	     www = (www) ALL, (root) /usr/bin/su www

     On	the host www, any user in the WEBMASTERS User_Alias (will, wendy, and
     wim), may run any command as user www (which owns the web pages) or sim-
     ply su(1) to www.

     ALL	     CDROM = NOPASSWD: /sbin/umount /CDROM,\
		     /sbin/mount -o nosuid\,nodev /dev/cd0a /CDROM

     Any user may mount	or unmount a CD-ROM on the machines in the CDROM
     Host_Alias	(orion,	perseus, hercules) without entering a password.	 This
     is	a bit tedious for users	to type, so it is a prime candidate for	encap-
     sulating in a shell script.

SECURITY NOTES
   Limitations of the `!' operator
     It	is generally not effective to ``subtract'' commands from ALL using the
     `!' operator.  A user can trivially circumvent this by copying the
     desired command to	a different name and then executing that.  For exam-
     ple:

     bill    ALL = ALL,	!SU, !SHELLS

     Doesn't really prevent bill from running the commands listed in SU	or
     SHELLS since he can simply	copy those commands to a different name, or
     use a shell escape	from an	editor or other	program.  Therefore, these
     kind of restrictions should be considered advisory	at best	(and rein-
     forced by policy).

     In	general, if a user has sudo ALL	there is nothing to prevent them from
     creating their own	program	that gives them	a root shell (or making	their
     own copy of a shell) regardless of	any `!'	elements in the	user specifi-
     cation.

   Security implications of fast_glob
     If	the fast_glob option is	in use,	it is not possible to reliably negate
     commands where the	path name includes globbing (aka wildcard) characters.
     This is because the C library's fnmatch(3)	function cannot	resolve	rela-
     tive paths.  While	this is	typically only an inconvenience	for rules that
     grant privileges, it can result in	a security issue for rules that	sub-
     tract or revoke privileges.

     For example, given	the following sudoers file entry:

     john    ALL = /usr/bin/passwd [a-zA-Z0-9]*, /usr/bin/chsh [a-zA-Z0-9]*,\
		   /usr/bin/chfn [a-zA-Z0-9]*, !/usr/bin/* root

     User john can still run /usr/bin/passwd root if fast_glob is enabled by
     changing to /usr/bin and running ./passwd root instead.

   Preventing shell escapes
     Once sudo executes	a program, that	program	is free	to do whatever it
     pleases, including	run other programs.  This can be a security issue
     since it is not uncommon for a program to allow shell escapes, which lets
     a user bypass sudo's access control and logging.  Common programs that
     permit shell escapes include shells (obviously), editors, paginators,
     mail and terminal programs.

     There are two basic approaches to this problem:

     restrict  Avoid giving users access to commands that allow	the user to
	       run arbitrary commands.	Many editors have a restricted mode
	       where shell escapes are disabled, though	sudoedit is a better
	       solution	to running editors via sudo.  Due to the large number
	       of programs that	offer shell escapes, restricting users to the
	       set of programs that do not is often unworkable.

     noexec    Many systems that support shared	libraries have the ability to
	       override	default	library	functions by pointing an environment
	       variable	(usually LD_PRELOAD) to	an alternate shared library.
	       On such systems,	sudo's noexec functionality can	be used	to
	       prevent a program run by	sudo from executing any	other pro-
	       grams.  Note, however, that this	applies	only to	native dynami-
	       cally-linked executables.  Statically-linked executables	and
	       foreign executables running under binary	emulation are not
	       affected.

	       The noexec feature is known to work on SunOS, Solaris, *BSD,
	       Linux, IRIX, Tru64 UNIX,	MacOS X, HP-UX 11.x and	AIX 5.3	and
	       above.  It should be supported on most operating	systems	that
	       support the LD_PRELOAD environment variable.  Check your	oper-
	       ating system's manual pages for the dynamic linker (usually
	       ld.so, ld.so.1, dyld, dld.sl, rld, or loader) to	see if
	       LD_PRELOAD is supported.

	       To enable noexec	for a command, use the NOEXEC tag as docu-
	       mented in the User Specification	section	above.	Here is	that
	       example again:

	       aaron   shanty =	NOEXEC:	/usr/bin/more, /usr/bin/vi

	       This allows user	aaron to run /usr/bin/more and /usr/bin/vi
	       with noexec enabled.  This will prevent those two commands from
	       executing other commands	(such as a shell).  If you are unsure
	       whether or not your system is capable of	supporting noexec you
	       can always just try it out and check whether shell escapes work
	       when noexec is enabled.

     Note that restricting shell escapes is not	a panacea.  Programs running
     as	root are still capable of many potentially hazardous operations	(such
     as	changing or overwriting	files) that could lead to unintended privilege
     escalation.  In the specific case of an editor, a safer approach is to
     give the user permission to run sudoedit (see below).

   Secure editing
     The sudoers plugin	includes sudoedit support which	allows users to
     securely edit files with the editor of their choice.  As sudoedit is a
     built-in command, it must be specified in the sudoers file	without	a
     leading path.  However, it	may take command line arguments	just as	a nor-
     mal command does.	Wildcards used in sudoedit command line	arguments are
     expected to be path names,	so a forward slash (`/') will not be matched
     by	a wildcard.

     Unlike other sudo commands, the editor is run with	the permissions	of the
     invoking user and with the	environment unmodified.	 More information may
     be	found in the description of the	-e option in sudo(8).

     For example, to allow user	operator to edit the ``message of the day''
     file:

	   operator	   sudoedit /etc/motd

     The operator user then runs sudoedit as follows:

	   $ sudoedit /etc/motd

     The editor	will run as the	operator user, not root, on a temporary	copy
     of	/etc/motd.  After the file has been edited, /etc/motd will be updated
     with the contents of the temporary	copy.

     Users should never	be granted sudoedit permission to edit a file that
     resides in	a directory the	user has write access to, either directly or
     via a wildcard.  If the user has write access to the directory it is pos-
     sible to replace the legitimate file with a link to another file, allow-
     ing the editing of	arbitrary files.  To prevent this, starting with ver-
     sion 1.8.16, symbolic links will not be followed in writable directories
     and sudoedit will refuse to edit a	file located in	a writable directory
     unless the	sudoedit_checkdir option has been disabled or the invoking
     user is root.  Additionally, in version 1.8.15 and	higher,	sudoedit will
     refuse to open a symbolic link unless either the sudoedit_follow option
     is	enabled	or the sudoedit	command	is prefixed with the FOLLOW tag	in the
     sudoers file.

   Time	stamp file checks
     sudoers will check	the ownership of its time stamp	directory
     (/var/run/sudo/ts by default) and ignore the directory's contents if it
     is	not owned by root or if	it is writable by a user other than root.
     Older versions of sudo stored time	stamp files in /tmp; this is no	longer
     recommended as it may be possible for a user to create the	time stamp
     themselves	on systems that	allow unprivileged users to change the owner-
     ship of files they	create.

     While the time stamp directory should be cleared at reboot	time, not all
     systems contain a /var/run	directory.  To avoid potential problems,
     sudoers will ignore time stamp files that date from before	the machine
     booted on systems where the boot time is available.

     Some systems with graphical desktop environments allow unprivileged users
     to	change the system clock.  Since	sudoers	relies on the system clock for
     time stamp	validation, it may be possible on such systems for a user to
     run sudo for longer than timestamp_timeout	by setting the clock back.  To
     combat this, sudoers uses a monotonic clock (which	never moves backwards)
     for its time stamps if the	system supports	it.

     sudoers will not honor time stamps	set far	in the future.	Time stamps
     with a date greater than current_time + 2 * TIMEOUT will be ignored and
     sudoers will log and complain.

     Since time	stamp files live in the	file system, they can outlive a	user's
     login session.  As	a result, a user may be	able to	login, run a command
     with sudo after authenticating, logout, login again, and run sudo without
     authenticating so long as the record's time stamp is within 5 minutes (or
     whatever value the	timeout	is set to in the sudoers file).	 When the
     tty_tickets option	is enabled, the	time stamp record includes the device
     number of the terminal the	user authenticated with.  This provides	per-
     tty granularity but time stamp records still may outlive the user's ses-
     sion.  The	time stamp record also includes	the session ID of the process
     that last authenticated.  This prevents processes in different terminal
     sessions from using the same time stamp record.  It also helps reduce the
     chance that a user	will be	able to	run sudo without entering a password
     when logging out and back in again	on the same terminal.

DEBUGGING
     Versions 1.8.4 and	higher of the sudoers plugin support a flexible	debug-
     ging framework that can help track	down what the plugin is	doing inter-
     nally if there is a problem.  This	can be configured in the sudo.conf(5)
     file.

     The sudoers plugin	uses the same debug flag format	as the sudo front-end:
     subsystem@priority.

     The priorities used by sudoers, in	order of decreasing severity, are:
     crit, err,	warn, notice, diag, info, trace	and debug.  Each priority,
     when specified, also includes all priorities higher than it.  For exam-
     ple, a priority of	notice would include debug messages logged at notice
     and higher.

     The following subsystems are used by the sudoers plugin:

     alias     User_Alias, Runas_Alias,	Host_Alias and Cmnd_Alias processing

     all       matches every subsystem

     audit     BSM and Linux audit code

     auth      user authentication

     defaults  sudoers file Defaults settings

     env       environment handling

     ldap      LDAP-based sudoers

     logging   logging support

     match     matching	of users, groups, hosts	and netgroups in the sudoers
	       file

     netif     network interface handling

     nss       network service switch handling in sudoers

     parser    sudoers file parsing

     perms     permission setting

     plugin    The equivalent of main for the plugin.

     pty       pseudo-tty related code

     rbtree    redblack	tree internals

     sssd      SSSD-based sudoers

     util      utility functions
     For example:

     Debug sudo	/var/log/sudo_debug match@info,nss@info

     For more information, see the sudo.conf(5)	manual.

SEE ALSO
     ssh(1), su(1), fnmatch(3),	glob(3), mktemp(3), strftime(3), sudo.conf(5),
     sudoers.ldap(5), sudo(8), sudo_plugin(8), visudo(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 file in the sudo distribution
     (https://www.sudo.ws/contributors.html) for an exhaustive list of people
     who have contributed to sudo.

CAVEATS
     The sudoers file should always be edited by the visudo command which
     locks the file and	does grammatical checking.  It is imperative that the
     sudoers file be free of syntax errors since sudo will not run with	a syn-
     tactically	incorrect sudoers file.

     When using	netgroups of machines (as opposed to users), if	you store
     fully qualified host name in the netgroup (as is usually the case), you
     either need to have the machine's host name be fully qualified as
     returned by the hostname command or use the fqdn option in	sudoers.

BUGS
     If	you feel you have found	a bug in sudo, please submit a bug report 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
     sudo 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 file
     distributed with sudo or https://www.sudo.ws/license.html for complete
     details.

Sudo 1.8.20p2			  May 8, 2017			 Sudo 1.8.20p2

NAME | DESCRIPTION | SUDOERS FILE FORMAT | SUDOERS OPTIONS | GROUP PROVIDER PLUGINS | LOG FORMAT | I/O LOG FILES | FILES | EXAMPLES | SECURITY NOTES | DEBUGGING | SEE ALSO | AUTHORS | CAVEATS | BUGS | SUPPORT | DISCLAIMER

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