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

     sudo, sudoedit - execute a command as another user

     sudo -h | -K | -k | -L | -V
     sudo -v [-AknS] [-a auth_type] [-g group name | #gid] [-p prompt]
          [-u user name | #uid]
     sudo -l[l] [-AknS] [-a auth_type] [-g group name | #gid] [-p prompt]
          [-U user name] [-u user name | #uid] [command]
     sudo [-AbEHnPS] [-a auth_type] [-C fd] [-c class | -]
          [-g group name | #gid] [-p prompt] [-u user name | #uid] [VAR=value]
          -i | -s [command]
     sudoedit [-AnS] [-a auth_type] [-C fd] [-c class | -]
              [-g group name | #gid] [-p prompt] [-u user name | #uid] file

     sudo allows a permitted user to execute a command as the superuser or
     another user, as specified by the sudoers file.  The real and effective
     uid and gid are set to match those of the target user, as specified in
     the password database, and the group vector is initialized based on the
     group database (unless the -P option was specified).  See the Command
     Environment section below for more details.

     sudo determines who is an authorized user by consulting the file
     /etc/sudoers.  By running sudo with the -v option, a user can update the
     time stamp without running a command.  If authentication is required,
     sudo will exit if the user's password is not entered within a
     configurable time limit.  The default password prompt timeout is 5

     When invoked as sudoedit, the -e option (described below), is implied.

     The options are as follows:

     -A          Normally, if sudo requires a password, it will read it from
                 the user's terminal.  If the -A (askpass) option is
                 specified, a (possibly graphical) helper program is executed
                 to read the user's password and output the password to the
                 standard output.  If the SUDO_ASKPASS environment variable is
                 set, it specifies the path to the helper program.  Otherwise,
                 the value specified by the askpass option in sudoers(5) is
                 used.  If no askpass program is available, sudo will exit
                 with an error.

     -a type     The -a (authentication type) option causes sudo to use the
                 specified authentication type when validating the user, as
                 allowed by /etc/login.conf.  The system administrator may
                 specify a list of sudo-specific authentication methods by
                 adding an ``auth-sudo'' entry in /etc/login.conf.  This
                 option is only available on systems that support BSD

     -b          The -b (background) option tells sudo to run the given
                 command in the background.  Note that if you use the -b
                 option you cannot use shell job control to manipulate the
                 process.  Most interactive commands will fail to work
                 properly in background mode.

     -C fd       Normally, sudo will close all open file descriptors other
                 than standard input, standard output and standard error.  The
                 -C (close from) option allows the user to specify a starting
                 point above the standard error (file descriptor three).
                 Values less than three are not permitted.  This option is
                 only available when the administrator has enabled the
                 closefrom_override option in sudoers(5).

     -c class    The -c (class) option causes sudo to run the specified
                 command with resources limited by the specified login class.
                 The class argument can be either a class name as defined in
                 /etc/login.conf, or a single `-' character.  Specifying a
                 class of - indicates that the command should be run
                 restricted by the default login capabilities for the user the
                 command is run as.  If the class argument specifies an
                 existing user class, the command must be run as root, or the
                 sudo command must be run from a shell that is already root.
                 This option is only available on systems with BSD login

     -E          The -E (preserve environment) option will override the
                 env_reset option in sudoers(5).  It is only available when
                 either the matching command has the SETENV tag or the setenv
                 option is set in sudoers(5).  sudo will return an error if
                 the -E option is specified and the user does not have
                 permission to preserve the environment.

     -e          The -e (edit) option indicates that, instead of running a
                 command, the user wishes to edit one or more files.  In lieu
                 of a command, the string "sudoedit" is used when consulting
                 the sudoers file.  If the user is authorized by sudoers, the
                 following steps are taken:

                  1.   Temporary copies are made of the files to be edited
                       with the owner set to the invoking user.

                  2.   The editor specified by the SUDO_EDITOR, VISUAL or
                       EDITOR environment variables (in that order) is run to
                       edit the temporary files.  If none of SUDO_EDITOR,
                       VISUAL or EDITOR are set, the first program listed in
                       the editor sudoers(5) option is used.

                  3.   If they have been modified, the temporary files are
                       copied back to their original location and the
                       temporary versions are removed.

                 If the specified file does not exist, it will be created.
                 Note that unlike most commands run by sudo, the editor is run
                 with the invoking user's environment unmodified.  If, for
                 some reason, sudo is unable to update a file with its edited
                 version, the user will receive a warning and the edited copy
                 will remain in a temporary file.

     -g group    Normally, sudo runs a command with the primary group set to
                 the one specified by the password database for the user the
                 command is being run as (by default, root).  The -g (group)
                 option causes sudo to run the command with the primary group
                 set to group instead.  To specify a gid instead of a group
                 name, use #gid.  When running commands as a gid, many shells
                 require that the `#' be escaped with a backslash (`\').  If
                 no -u option is specified, the command will be run as the
                 invoking user (not root).  In either case, the primary group
                 will be set to group.

     -H          The -H (HOME) option option sets the HOME environment
                 variable to the home directory of the target user (root by
                 default) as specified by the password database.  The default
                 handling of the HOME environment variable depends on
                 sudoers(5) settings.  By default, sudo will not modify HOME
                 (see set_home and always_set_home in sudoers(5)).

     -h          The -h (help) option causes sudo to print a short help
                 message to the standard output and exit.

     -i [command]
                 The -i (simulate initial login) option runs the shell
                 specified by the password database entry of the target user
                 as a login shell.  This means that login-specific resource
                 files such as .profile or .login will be read by the shell.
                 If a command is specified, it is passed to the shell for
                 execution via the shell's -c option.  If no command is
                 specified, an interactive shell is executed.  sudo attempts
                 to change to that user's home directory before running the
                 shell.  It also initializes the environment to a minimal set
                 of variables, similar to what is present when a user logs in.
                 The Command Environment section below documents in detail how
                 the -i option affects the environment in which a command is

     -K          The -K (sure kill) option is like -k except that it removes
                 the user's time stamp file entirely and may not be used in
                 conjunction with a command or other option.  This option does
                 not require a password.

     -k [command]
                 When used alone, the -k (kill) option to sudo invalidates the
                 user's time stamp file.  The next time sudo is run a password
                 will be required.  This option does not require a password
                 and was added to allow a user to revoke sudo permissions from
                 a .logout file.

                 When used in conjunction with a command or an option that may
                 require a password, the -k option will cause sudo to ignore
                 the user's time stamp file.  As a result, sudo will prompt
                 for a password (if one is required by sudoers) and will not
                 update the user's time stamp file.

     -L          The -L (list defaults) option will list the parameters that
                 may be set in a Defaults line along with a short description
                 for each.  This option will be removed from a future version
                 of sudo.

     -l[l] [command]
                 If no command is specified, the -l (list) option will list
                 the allowed (and forbidden) commands for the invoking user
                 (or the user specified by the -U option) on the current host.
                 If a command is specified and is permitted by sudoers, the
                 fully-qualified path to the command is displayed along with
                 any command line arguments.  If command is specified but not
                 allowed, sudo will exit with a status value of 1.  If the -l
                 option is specified with an l argument (i.e. -ll), or if -l
                 is specified multiple times, a longer list format is used.

     -n          The -n (non-interactive) option prevents sudo from prompting
                 the user for a password.  If a password is required for the
                 command to run, sudo will display an error message and exit.

     -P          The -P (preserve group vector) option causes sudo to preserve
                 the invoking user's group vector unaltered.  By default, sudo
                 will initialize the group vector to the list of groups the
                 target user is in.  The real and effective group IDs,
                 however, are still set to match the target user.

     -p prompt   The -p (prompt) option allows you to override the default
                 password prompt and use a custom one.  The following percent
                 (`%') escapes are supported:

                 %H  expanded to the host name including the domain name (on
                     if the machine's host name is fully qualified or the fqdn
                     option is set in sudoers(5))

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

                 %p  expanded to the name of the user whose password is being
                     requested (respects the rootpw, targetpw, and runaspw
                     flags in sudoers(5))

                 %U  expanded to the login name of the user the command will
                     be run as (defaults to root unless the -u option is also

                 %u  expanded to the invoking user's login name

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

                 The prompt specified by the -p option will override the
                 system password prompt on systems that support PAM unless the
                 passprompt_override flag is disabled in sudoers.

     -S          The -S (stdin) option causes sudo to read the password from
                 the standard input instead of the terminal device.  The
                 password must be followed by a newline character.

     -s [command]
                 The -s (shell) option runs the shell specified by the SHELL
                 environment variable if it is set or the shell as specified
                 in the password database.  If a command is specified, it is
                 passed to the shell for execution via the shell's -c option.
                 If no command is specified, an interactive shell is executed.

     -U user     The -U (other user) option is used in conjunction with the -l
                 option to specify the user whose privileges should be listed.
                 Only root or a user with the ALL privilege on the current
                 host may use this option.

     -u user     The -u (user) option causes sudo to run the specified command
                 as a user other than root.  To specify a uid instead of a
                 user name, #uid.  When running commands as a uid, many shells
                 require that the `#' be escaped with a backslash (`\').  Note
                 that if the targetpw Defaults option is set (see sudoers(5)),
                 it is not possible to run commands with a uid not listed in
                 the password database.

     -V          The -V (version) option causes sudo to print its version
                 string and exit.  If the invoking user is already root the -V
                 option will display the arguments passed to configure when
                 sudo was built as well a list of the defaults sudo was
                 compiled with as well as the machine's local network

     -v          When given the -v (validate) option, sudo will update the
                 user's time stamp file, authenticating the user's password if
                 necessary.  This extends the sudo timeout for another 5
                 minutes (or whatever the timeout is set to in sudoers) but
                 does not run a command.

     --          The -- option indicates that sudo should stop processing
                 command line arguments.

     Environment variables to be set for the command may also be passed on the
     command line in the form of VAR=value, e.g.
     LD_LIBRARY_PATH=/usr/local/pkg/lib.  Variables passed on the command line
     are subject to the same restrictions as normal environment variables with
     one important exception.  If the setenv option is set in sudoers, the
     command to be run has the SETENV tag set or the command matched is ALL,
     the user may set variables that would otherwise be forbidden.  See
     sudoers(5) for more information.

   Authentication and Logging
     sudo requires that most users authenticate themselves by default.  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 authentication has been
     disabled for the user or command in the sudoers file.  Unlike su(1), when
     sudo requires authentication, it validates the invoking user's
     credentials, not the target user's (or root's) credentials.  This can be
     changed via the rootpw, targetpw and runaspw Defaults entries in sudoers.

     If a user who is not listed in sudoers 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 sudoers Defaults entry and defaults to

     Note that mail will not be sent if an unauthorized user tries to run sudo
     with the -l or -v option.  This allows users to determine for themselves
     whether or not they are allowed to use sudo.

     If sudo is run by root and the SUDO_USER environment variable is set, its
     value will be used 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 lookup
     is still done for root, not the user specified by SUDO_USER.

     sudo uses time stamp files for credential caching.  Once a user has been
     authenticated, the time stamp is updated and the user may then use sudo
     without a password for a short period of time (5 minutes unless
     overridden by the timeout option).  By default, sudo uses a tty-based
     time stamp which means that there is a separate time stamp for each of a
     user's login sessions.  The tty_tickets option can be disabled to force
     the use of a single time stamp for all of a user's sessions.

     sudo can log both successful and unsuccessful attempts (as well as
     errors) to syslog(3), a log file, or both.  By default, sudo will log via
     syslog(3) but this is changeable via the syslog and logfile Defaults

     sudo also supports logging a command's input and output streams.  I/O
     logging is not on by default but can be enabled using the log_input and
     log_output Defaults flags as well as the LOG_INPUT and LOG_OUTPUT command

   Command Environment
     Since environment variables can influence program behavior, sudo provides
     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 be configured to handle 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
     settings in /etc/login.conf.  The new environment contains the TERM,
     addition to variables from the invoking process permitted by the
     env_check and env_keep options.  This is effectively a whitelist for
     environment variables.

     If, however, the env_reset option is disabled, any variables not
     explicitly 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.  Since it is not possible to blacklist all potentially
     dangerous environment variables, use of the default env_reset behavior is

     In all cases, environment variables with a value beginning with () are
     removed as they could be interpreted as bash functions.  The list of
     environment variables that sudo allows or denies is contained in the
     output of ``sudo -V'' when run as root.

     Note that the dynamic linker on most operating systems will remove
     variables 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

     As a special case, if sudo's -i option (initial login) is specified, sudo
     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 option is enabled, the path and
     setenv variables in /etc/login.conf are also applied.  All other
     environment variables are removed.

     Finally, if the env_file option is defined, any variables present in that
     file will be set to their specified values as long as they would not
     conflict with an existing environment variable.

     Upon successful execution of a program, the exit status from sudo will
     simply be the exit status of the program that was executed.

     Otherwise, sudo exits with a value of 1 if there is a
     configuration/permission problem or if sudo cannot execute the given
     command.  In the latter case the error string is printed to the standard
     error.  If sudo cannot stat(2) one or more entries in the user's PATH, an
     error is printed on stderr.  (If the directory does not exist or if it is
     not really a directory, the entry is ignored and no error is printed.)
     This should not happen under normal circumstances.  The most common
     reason for stat(2) to return ``permission denied'' is if you are running
     an automounter and one of the directories in your PATH is on a machine
     that is currently unreachable.

     sudo can log events using either syslog(3) or a simple log file.  In each
     case the log format is almost identical.

   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
                   command'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
        commands 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
        number of tries will vary based on the number of failed attempts and
        the value of the passwd_tries sudoers option.

     a password is required
        The -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, sudo will log a message and, in most cases, send a
     message to the administrator via email.  Possible errors include:

     parse error in /etc/sudoers near line N
        sudo 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
        setting, could not be found in the password database.

     unable to open/read /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, sudo tries to open sudoers
        using group permissions to avoid this problem.

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

     /etc/sudoers is not a regular file
        The /etc/sudoers file exists but is not a regular file or symbolic

     /etc/sudoers is owned by uid N, should be 0
        The sudoers file has the wrong owner.

     /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).

     /etc/sudoers is owned by gid N, should be 1
        The sudoers file has the wrong group ownership.

     unable to open /var/run/sudo/username/ttyname
        sudoers was unable to read or create the user's time stamp file.

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

     unable to mkdir to /var/run/sudo/username
        sudoers was unable to create the user's time stamp directory.

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

     On most systems, syslog(3) has a relatively small log buffer.  To prevent
     the command line arguments from being truncated, sudo will split up log
     messages that are larger than 960 characters (not including the date,
     hostname, and the string ``sudo'').  When a message is split, additional
     parts will include the string ``(command continued)'' after the user name
     and before the continued command line arguments.

   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 sudoers 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 sudoers option is set to 0 (or negated with a `!'), word
          wrap will be disabled.

     sudo tries to be safe when executing external commands.

     To prevent command spoofing, sudo checks "." and "" (both denoting
     current directory) last when searching for a command in the user's PATH
     (if one or both are in the PATH).  Note, however, that the actual PATH
     environment variable is not modified and is passed unchanged to the
     program that sudo executes.

     sudo will check the ownership of its time stamp directory (/var/run/sudo
     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.  On systems that
     allow non-root users to give away files via chown(2), if the time stamp
     directory is located in a world-writable directory (e.g., /tmp), it is
     possible for a user to create the time stamp directory before sudo is
     run.  However, because sudo checks the ownership and mode of the
     directory and its contents, the only damage that can be done is to
     ``hide'' files by putting them in the time stamp dir.  This is unlikely
     to happen since once the time stamp dir is owned by root and inaccessible
     by any other user, the user placing files there would be unable to get
     them back out.

     sudo 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 sudo
     will log and complain.  This is done to keep a user from creating his/her
     own time stamp with a bogus date on systems that allow users to give away
     files if the time stamp directory is located in a world-writable

     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 time stamp file's modification time is
     within 5 minutes (or whatever the timeout is set to in sudoers).  When
     the tty_tickets sudoers option is enabled, the time stamp has per-tty
     granularity but still may outlive the user's session.

     Please note that sudo will normally only log the command it explicitly
     runs.  If a user runs a command such as sudo su or sudo sh, subsequent
     commands run from that shell are not subject to sudo's security policy.
     The same is true for commands that offer shell escapes (including most
     editors).  If I/O logging is enabled, subsequent commands will have their
     input and/or output logged, but there will not be traditional logs for
     those commands.  Because of this, care must be taken when giving users
     access to commands via sudo to verify that the command does not
     inadvertently give the user an effective root shell.  For more
     information, please see the PREVENTING SHELL ESCAPES section in

     To prevent the disclosure of potentially sensitive information, sudo
     disables core dumps by default while it is executing (they are re-enabled
     for the command that is run).

     For information on the security implications of sudoers entries, please
     see the SECURITY NOTES section in sudoers(5).

     sudo utilizes the following environment variables:

     EDITOR           Default editor to use in -e (sudoedit) mode if neither
                      SUDO_EDITOR nor VISUAL is set.

     MAIL             In -i mode or when env_reset is enabled in sudoers, set
                      to the mail spool of the target user.

     HOME             Set to the home directory of the target user if -H it
                      specified, always_set_home is set in sudoers, or when
                      the -s option is specified and set_home is set in

     PATH             Set to a sane value if the secure_path option is set in
                      the sudoers file.

     SHELL            Used to determine shell to run with -s option.

     SUDO_ASKPASS     Specifies the path to a helper program used to read the
                      password if no terminal is available or if the -A option
                      is specified.

     SUDO_COMMAND     Set to the command run by sudo.

     SUDO_EDITOR      Default editor to use in -e (sudoedit) mode.

     SUDO_GID         Set to the group ID of the user who invoked sudo.

     SUDO_PROMPT      Used as the default password prompt.

     SUDO_PS1         If set, PS1 will be set to its value for the program
                      being run.

     SUDO_UID         Set to the user ID of the user who invoked sudo.

     SUDO_USER        Set to the login name of the user who invoked sudo.

     USER             Set to the target user (root unless the -u option is

     VISUAL           Default editor to use in -e (sudoedit) mode if
                      SUDO_EDITOR is not set.

     /etc/sudoers              List of who can run what

     /var/run/sudo             Directory containing time stamps

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

     Note: the following examples assume suitable sudoers(5) entries.

     To get a file listing of an unreadable directory:

           $ sudo ls /usr/local/protected

     To list the home directory of user yaz on a machine where the file system
     holding ~yaz is not exported as root:

           $ sudo -u yaz ls ~yaz

     To edit the index.html file as user www:

           $ sudo -u www vi ~www/htdocs/index.html

     To view system logs only accessible to root and users in the adm group:

           $ sudo -g adm view /var/log/syslog

     To run an editor as jim with a different primary group:

           $ sudo -u jim -g audio vi ~jim/sound.txt

     To shut down a machine:

           $ sudo shutdown -r +15 "quick reboot"

     To make a usage listing of the directories in the /home partition.  Note
     that this runs the commands in a sub-shell to make the cd and file
     redirection work.

           $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"

     grep(1), su(1), stat(2), login_cap(3), passwd(5), sudoers(5),
     sudoreplay(8), visudo(8)

     See the HISTORY file in the sudo distribution
     ( for a brief history of sudo.

     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
     ( for an exhaustive list of
     people who have contributed to sudo.

     There is no easy way to prevent a user from gaining a root shell if that
     user is allowed to run arbitrary commands via sudo.  Also, many programs
     (such as editors) allow the user to run commands via shell escapes, thus
     avoiding sudo's checks.  However, on most systems it is possible to
     prevent shell escapes with sudo ' s noexec functionality.  See the
     sudoers(5) manual for details.

     It is not meaningful to run the cd command directly via sudo, e.g.,

           $ sudo cd /usr/local/protected

     since when the command exits the parent process (your shell) will still
     be the same.  Please see the EXAMPLES section for more information.

     Running shell scripts via sudo can expose the same kernel bugs that make
     setuid shell scripts unsafe on some operating systems (if your OS has a
     /dev/fd/ directory, setuid shell scripts are generally safe).

     If you feel you have found a bug in sudo, please submit a bug report at

     Limited free support is available via the sudo-users mailing list, see to subscribe or search the

     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 for
     complete details.

FreeBSD 11.0-PRERELEASE         August 17, 2012        FreeBSD 11.0-PRERELEASE


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