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SUDOERS(5)                                  MAINTENANCE COMMANDS                                  SUDOERS(5)



NAME
       sudoers - list of which users may execute what

DESCRIPTION
       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 necessarily the most specific match).

       The sudoers grammar will be described below in Extended Backus-Naur Form (EBNF).  Don't despair if
       you don't know what EBNF is; 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, confuse 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 underscore 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

       The definitions of what constitutes a valid alias member follow.

        User_List ::= User |
                      User ',' User_List

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

       A User_List is made up of one or more user names, uids (prefixed with '#'), system groups (prefixed
       with '%'), netgroups (prefixed with '+') 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.

       A user name, group, netgroup or nonunix_group may be enclosed in double quotes to avoid the need for
       escaping special characters.  Alternately, special characters may be specified in escaped hex mode,
       e.g. \x20 for space.

       The nonunix_group syntax depends on the underlying implementation.  For instance, the QAS AD backend
       supports the following formats:

          Group in the same domain: "Group Name"

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

          Group SID: "S-1-2-34-5678901234-5678901234-5678901234-567"

       Note that quotes around group names are optional.  Unquoted strings must use a backslash (\) to
       escape spaces and the '@' symbol.

        Runas_List ::= Runas_Member |
                       Runas_Member ',' Runas_List

        Runas_Member ::= '!'* user name |
                         '!'* '#'uid |
                         '!'* '%'group |
                         '!'* +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.  If
       you do not specify a netmask along with the network number, 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,
       the corresponding netmask will be used.  The netmask may be specified either in standard IP address
       notation (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 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.

        Cmnd_List ::= Cmnd |
                      Cmnd ',' Cmnd_List

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

        Cmnd ::= '!'* commandname |
                 '!'* directory |
                 '!'* "sudoedit" |
                 '!'* Cmnd_Alias

       A Cmnd_List is a list of one or more commandnames, directories, and other aliases.  A commandname is
       a fully qualified file name which may include shell-style wildcards (see the Wildcards section
       below).  A simple 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 subdirectories 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 characters must be escaped with a '\' if they are used in command arguments: ',', ':', '=',
       '\'.  The special command "sudoedit" is used to permit a user to run sudo with the -e option (or as
       sudoedit).  It may take command line arguments just as a normal command does.

   Defaults
       Certain configuration options may be changed from their default values at runtime 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 backslash (\).

       Lists have two additional assignment operators, += and -=.  These operators 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 and user Defaults first, then runas
       Defaults and finally command defaults.

       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? Tag_Spec* Cmnd

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

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

       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 parentheses.  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 specified, 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 no Runas_Spec is specified the command 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

       In the following example, user tcm may run commands that access a modem device file with the dialer
       group.  Note that in this example only the group will be set, the command still runs as user tcm.

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

   Tag_Spec
       A command may have zero or more tags associated with it.  There are eight possible tag values,
       NOPASSWD, PASSWD, NOEXEC, EXEC, SETENV, NOSETENV, LOG_INPUT, NOLOG_INPUT, LOG_OUTPUT and
       NOLOG_OUTPUT.  Once a tag is set on a Cmnd, subsequent Cmnds in the Cmnd_Spec_List, inherit the tag
       unless it is overridden by the opposite tag (i.e.: PASSWD overrides NOPASSWD and NOEXEC overrides
       EXEC).

       NOPASSWD and PASSWD

       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 overridden via the verifypw and listpw options.

       NOEXEC and EXEC

       If sudo has been compiled with noexec support and the underlying operating 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.

       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, any environment variables set on the command line way 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.  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.

       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.

   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 POSIX glob(3) and
       fnmatch(3) routines.  Note that these are not regular expressions.

       *       Matches any set of zero or more characters.

       ?       Matches any single character.

       [...]   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 "}".

       POSIX character classes may also 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 path name.  When
       matching the command line arguments, however, a slash does get matched by wildcards.  This is to make
       a path like:

           /usr/bin/*

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

   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 entry it means that
               command is not allowed to be run with any arguments.

   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 directives.

       This can be used, for example, to keep a site-wide sudoers file in addition to a local, per-machine
       file.  For the sake of this example the site-wide sudoers 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.

       The file name may include the %h escape, signifying the short form of the host name.  I.e., 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 sudo.d directory that the system package manager
       can drop sudoers rules into as part of package installation.  For example, given:

       #includedir /etc/sudoers.d

       sudo will 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 temporary/backup files.  Files are
       parsed in sorted lexical order.  That is, /etc/sudoers.d/_1_first will be parsed before
       /etc/sudoers.d/1__second.  Be aware that because the sorting is lexical, not numeric,
       /etc/sudoers.d/1_whoops would be loaded after /etc/sudoers.d/1__second.  Using a consistent number of
       leading zeroes in the file names can be used to avoid such problems.

       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.

   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 preference 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 both in an alias and in front of a
       Cmnd.  This allows one to exclude certain values.  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.

       Whitespace between elements in a list as well as special syntactic characters 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 earlier.  A list of all
       supported Defaults parameters, grouped by type, are listed below.

       Boolean Flags:

       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 HOME is already set when the the
                       env_reset option is enabled, so always_set_home is only effective for configurations
                       where env_reset is disabled.  This flag is off by default.

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

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

       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.

       env_editor      If set, visudo will use the value of the EDITOR or VISUAL environment variables
                       before falling back on the default editor list.  Note that this may create a security
                       hole as it allows 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.  This flag is off by default.

       env_reset       If set, sudo will reset the environment to only contain the LOGNAME, MAIL, SHELL,
                       USER, USERNAME and the SUDO_* variables.  Any variables in the caller's environment
                       that match the env_keep and env_check lists are then added.  The default contents of
                       the env_keep and env_check lists are displayed when sudo is run by root with the -V
                       option.  If the secure_path 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 (automounted).  The fast_glob option causes sudo to
                       use the fnmatch(3) function, which does not access the file system to do its
                       matching.  The disadvantage of fast_glob is that it is unable to 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 trivially bypassed.  As such, this option should not be used when sudoers
                       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.
                       I.e., instead of myhost you would use myhost.mydomain.edu.  You may still use the
                       short form if you wish (and even mix the two).  Beware that turning on fqdn requires
                       sudo to make DNS lookups which may make sudo unusable if DNS stops working (for
                       example if the machine is not plugged into the network).  Also note that you must use
                       the host's official name as DNS knows it.  That is, you may not use a host alias
                       (CNAME entry) due to performance issues and the fact that there is no way to get all
                       aliases from DNS.  If your machine's host name (as returned by the hostname command)
                       is already fully qualified you shouldn't need to set fqdn.  This flag is off by
                       default.

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

       ignore_local_sudoers
                       If set via LDAP, parsing of /etc/sudoers will be skipped.  This is intended for
                       Enterprises that wish to prevent the usage of local sudoers files so that only LDAP
                       is used.  This thwarts the efforts of rogue operators who would attempt to add roles
                       to /etc/sudoers.  When this option is present, /etc/sudoers does not even need to
                       exist. Since this option tells sudo how to behave when no specific LDAP entries have
                       been matched, this sudoOption is only meaningful for the cn=defaults section.  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-syslog) sudo log file.  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 (OPT) scheme such as S/Key or OPIE, a two-line twoline
                       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 off by default.

       mail_always     Send mail to the mailto user every time a users 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.  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.

       noexec          If set, all commands run via sudo will behave as if the NOEXEC tag has been set,
                       unless overridden by a EXEC tag.  See the description of NOEXEC and EXEC below as
                       well as the "PREVENTING SHELL ESCAPES" section at the end of this manual.  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 disadvantage 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.

       passprompt_override
                       The password prompt specified by passprompt will normally only be used if the
                       password prompt provided by systems such as PAM matches the string "Password:".  If
                       passprompt_override is set, passprompt will always be used.  This flag is off 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 vector 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.  Disabling 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.  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.  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 the env_reset option is enabled, so set_home is only effective for
                       configurations where env_reset is disabled.  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 if the env_reset option has
                       not been disabled, entries in the env_keep list will override the value of
                       set_logname.  This flag is on by default.

       setenv          Allow the user to disable the env_reset option from the command line.  Additionally,
                       environment 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 potentially
                       dangerous functionality when a program is run setuid.  This option is only effective
                       on systems with either the setreuid() or setresuid() function.  This flag is off by
                       default.

       targetpw        If set, sudo will prompt for the password of the user specified by the -u option
                       (defaults to root) instead of the password of the invoking user.  In addition, the
                       timestamp file name will include the target user's name.  Note that this flag
                       precludes the use of a uid not listed in the passwd database as an argument to the -u
                       option.  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 connected 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.

                       Input is logged to the /var/log/sudo-io directory using a unique session ID that is
                       included in the normal sudo log line, prefixed with TSID=.

       log_output      If set, sudo will run the command in a pseudo tty and log all output that is sent to
                       the screen, similar to the script(1) command.  If the standard output or standard
                       error is not connected to the user's tty, due to I/O redirection or because the
                       command is part of a pipeline, that output is also captured and stored in separate
                       log files.

                       Output is logged to the /var/log/sudo-io directory using a unique session ID that is
                       included in the normal sudo log line, prefixed with TSID=.

                       Output logs may be viewed with the sudoreplay(8) utility, which can also be used to
                       list or search the available logs.

       tty_tickets     If set, users must authenticate on a per-tty basis.  With this flag enabled, sudo
                       will use a file named for the tty the user is logged in on in the user's time stamp
                       directory.  If disabled, the time stamp of the directory is used instead.  This flag
                       is on by default.

       umask_override  If set, sudo will set the umask as specified by sudoers without modification.  This
                       makes it possible to specify a more permissive umask in sudoers than the user's own
                       umask and 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_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.

       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 visible on the screen.  This makes it
                       possible to run things like "rsh somehost sudo ls" since rsh(1) does not allocate a
                       tty.  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.

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

       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 insufficient,
                       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 fractional 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 timestamp will never expire.  This can be used
                       to allow users to create or delete their own timestamps via sudo -v and sudo -k
                       respectively.

       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 0022.  This guarantees that sudo never lowers 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 environment variable if possible, or
                       the first editor in the list that exists and is executable.  The default is
                       "/usr/bin/vi".

       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     Path to a shared library containing dummy versions of the execv(), execve() and
                       fexecve() library functions that just return an error.  This is used to implement the
                       noexec functionality on systems that support LD_PRELOAD or its equivalent.  Defaults
                       to /usr/local/libexec/sudo_noexec.dylib.

       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 (`%') escapes
                       are supported:

                       %H  expanded to the local host name including the domain name (on if the machine's
                           host name is fully qualified or the fqdn option is set)

                       %h  expanded to the local host name without the domain name

                       %p  expanded to the user whose password is being asked for (respects the rootpw,
                           targetpw and runaspw flags in sudoers)

                       %U  expanded to the login name of the user the command will be run as (defaults to
                           root)

                       %u  expanded to the invoking user's login name

                       %%  two consecutive % characters are collapsed into a single % character

                       The default value is Password:.

       runas_default   The default user to run commands as if the -u option is not specified on the command
                       line.  This defaults to root.  Note that if runas_default is set it must occur before
                       any Runas_Alias specifications.

       syslog_badpri   Syslog priority to use when user authenticates unsuccessfully.  Defaults to alert.

       syslog_goodpri  Syslog priority to use when user authenticates successfully.  Defaults to notice.

       sudoers_locale  Locale to use when parsing the sudoers file.  Note that changing the locale may
                       affect how sudoers is interpreted.  Defaults to "C".

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

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

       Strings that can be used in a boolean context:

       askpass     The askpass option specifies the fully qualified path to a helper program used to read
                   the user's password when no terminal is available.  This may be the case when sudo is
                   executed from a graphical (as opposed to text-based) application.  The program specified
                   by askpass should display the argument passed to it as the prompt and write the user's
                   password to the standard output.  The value of askpass may be overridden by the
                   SUDO_ASKPASS environment variable.

       env_file    The env_file options 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 subject to other sudo
                   environment settings such as env_keep and env_check.

       exempt_group
                   Users in this group are exempt from password and PATH requirements.  This is not set by
                   default.

       lecture     This option controls when a short lecture will be printed along with the password prompt.
                   It has the following possible values:

                   always  Always lecture the user.

                   never   Never lecture the user.

                   once    Only lecture the user the first time they run sudo.

                   If no value is specified, a value of once is implied.  Negating the option results in a
                   value of never being used.  The default value is once.

       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 entries for the current host must have the NOPASSWD flag
                           set to avoid entering a password.

                   always  The user must always enter a password to use the -l option.

                   any     At least one of the user's sudoers entries for the current host must have the
                           NOPASSWD flag set to avoid entering a password.

                   never   The user need never enter a password to use the -l option.

                   If no value is specified, a value of any is implied.  Negating the option results in a
                   value of never being used.  The default value is any.

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

       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 warning and error mail.  The address
                   should be enclosed in double 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.

       secure_path Path used for every command run from sudo.  If you don't trust the people running sudo to
                   have a sane PATH environment variable you may want to use this.  Another use is if you
                   want to 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.

       verifypw    This option controls when a password will be required when a user runs sudo with the -v
                   option.  It has the following possible values:

                   all     All the user's sudoers entries for the current host must have the NOPASSWD flag
                           set to avoid entering a password.

                   always  The user must always enter a password to use the -v option.

                   any     At least one of the user's sudoers entries for the current host must have the
                           NOPASSWD flag set to avoid entering a password.

                   never   The user need never enter a password to use the -v option.

                   If no value is specified, a value of all is implied.  Negating the option results in a
                   value of never being used.  The default value is all.

       Lists that can be used in a boolean context:

       env_check       Environment variables to be removed from the user's environment if the variable's
                       value contains % or / characters.  This can be used to guard against printf-style
                       format vulnerabilities in poorly-written programs.  The argument may be a double-quoted, doublequoted,
                       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 aforementioned check.  The default 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 default
                       list of environment variables to remove is displayed when sudo is run by root with
                       the -V option.  Note that many operating systems will remove potentially 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 spaceseparated
                       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 default list of variables to keep is displayed when sudo is run by
                       root with the -V option.

       When logging via syslog(3), sudo accepts the following values for the syslog facility (the value of
       the syslog Parameter): authpriv (if your OS supports it), auth, daemon, user, local0, local1, local2,
       local3, local4, local5, local6, and local7.  The following syslog priorities are supported: alert,
       crit, debug, emerg, err, info, notice, and warning.

FILES
       /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

EXAMPLES
       Below are example sudoers 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
        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).

        # 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/.

        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.  Note that
       this assumes passwd(1) does not take multiple user names on the command line.

        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.

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

       The user steve may run any command in the directory /usr/local/op_commands/ 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 simply 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 encapsulating in a shell script.

SECURITY NOTES
       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 example:

           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 reinforced by
       policy).

       Furthermore, 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 relative paths.  While this is typically only an inconvenience for
       rules that grant privileges, it can result in a security issue for rules that subtract or revoke
       privileges.

       For example, given the following sudoers 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 if 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 programs.  Note, however, that this applies only to native
                 dynamically-linked executables.  Statically-linked executables and foreign executables
                 running under binary emulation are not affected.

                 To tell whether or not sudo supports noexec, you can run the following as root:

                     sudo -V | grep "dummy exec"

                 If the resulting output contains a line that begins with:

                     File containing dummy exec functions:

                 then sudo may be able to replace the exec family of functions in the standard library with
                 its own that simply return an error.  Unfortunately, there is no foolproof way to know
                 whether or not noexec will work at compile-time.  noexec should work on SunOS, Solaris,
                 *BSD, Linux, IRIX, Tru64 UNIX, MacOS X, and HP-UX 11.x.  It is known not to work on AIX and
                 UnixWare.  noexec is expected to work on most operating systems that support the LD_PRELOAD
                 environment variable.  Check your operating 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 documented 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 see if it works.

       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 ALSO
       rsh(1), su(1), fnmatch(3), glob(3), sudo(8), visudo(8)

CAVEATS
       The sudoers file should always be edited by the visudo command which locks the file and does
       grammatical checking. It is imperative that sudoers be free of syntax errors since sudo will not run
       with a syntactically 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 http://www.sudo.ws/sudo/bugs/

SUPPORT
       Limited free support is available via the sudo-users mailing list, see
       http://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, including, 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 http://www.sudo.ws/sudo/license.html for complete details.



1.7.4                                           July 21, 2010                                     SUDOERS(5)

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