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sudo(8)                      System Manager's Manual                     sudo(8)


NAME

     sudo, sudoedit - execute a command as another user


SYNOPSIS

     sudo -h | -K | -k | -V
     sudo -v [-ABkNnS] [-g group] [-h host] [-p prompt] [-u user]
     sudo -l [-ABkNnS] [-g group] [-h host] [-p prompt] [-U user] [-u user]
          [command]
     sudo [-ABbEHnPS] [-C num] [-D directory] [-g group] [-h host] [-p prompt]
          [-R directory] [-T timeout] [-u user] [VAR=value] [-i | -s] [command]
     sudoedit [-ABkNnS] [-C num] [-D directory] [-g group] [-h host] [-p prompt]
              [-R directory] [-T timeout] [-u user] file ...


DESCRIPTION

     sudo allows a permitted user to execute a command as the superuser or
     another user, as specified by the security policy.  The invoking user's
     real (not effective) user-ID is used to determine the user name with which
     to query the security policy.

     sudo supports a plugin architecture for security policies, auditing, and
     input/output logging.  Third parties can develop and distribute their own
     plugins to work seamlessly with the sudo front-end.  The default security
     policy is sudoers, which is configured via the file /opt/local/etc/sudoers,
     or via LDAP.  See the Plugins section for more information.

     The security policy determines what privileges, if any, a user has to run
     sudo.  The policy may require that users authenticate themselves with a
     password or another authentication mechanism.  If authentication is
     required, sudo will exit if the user's password is not entered within a
     configurable time limit.  This limit is policy-specific; the default
     password prompt timeout for the sudoers security policy is 0 minutes.

     Security policies may support credential caching to allow the user to run
     sudo again for a period of time without requiring authentication.  By
     default, the sudoers policy caches credentials on a per-terminal basis for
     5 minutes.  See the timestamp_type and timestamp_timeout options in
     sudoers(5) for more information.  By running sudo with the -v option, a
     user can update the cached credentials without running a command.

     On systems where sudo is the primary method of gaining superuser
     privileges, it is imperative to avoid syntax errors in the security policy
     configuration files.  For the default security policy, sudoers(5), changes
     to the configuration files should be made using the sudo(8) utility which
     will ensure that no syntax errors are introduced.

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

     Security policies and audit plugins may log successful and failed attempts
     to run sudo.  If an I/O plugin is configured, the running command's input
     and output may be logged as well.

     The options are as follows:

     -A, --askpass
                 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, if sudo.conf(5)
                 contains a line specifying the askpass program, that value will
                 be used.  For example:

                     # Path to askpass helper program
                     Path askpass /usr/X11R6/bin/ssh-askpass

                 If no askpass program is available, sudo will exit with an
                 error.

     -B, --bell  Ring the bell as part of the password prompt when a terminal is
                 present.  This option has no effect if an askpass program is
                 used.

     -b, --background
                 Run the given command in the background.  It is not possible to
                 use shell job control to manipulate background processes
                 started by sudo.  Most interactive commands will fail to work
                 properly in background mode.

     -C num, --close-from=num
                 Close all file descriptors greater than or equal to num before
                 executing a command.  Values less than three are not permitted.
                 By default, sudo will close all open file descriptors other
                 than standard input, standard output, and standard error when
                 executing a command.  The security policy may restrict the
                 user's ability to use this option.  The sudoers policy only
                 permits use of the -C option when the administrator has enabled
                 the closefrom_override option.

     -D directory, --chdir=directory
                 Run the command in the specified directory instead of the
                 current working directory.  The security policy may return an
                 error if the user does not have permission to specify the
                 working directory.

     -E, --preserve-env
                 Indicates to the security policy that the user wishes to
                 preserve their existing environment variables.  The security
                 policy may return an error if the user does not have permission
                 to preserve the environment.

     --preserve-env=list
                 Indicates to the security policy that the user wishes to add
                 the comma-separated list of environment variables to those
                 preserved from the user's environment.  The security policy may
                 return an error if the user does not have permission to
                 preserve the environment.  This option may be specified
                 multiple times.

     -e, --edit  Edit one or more files instead of running a command.  In lieu
                 of a path name, the string "sudoedit" is used when consulting
                 the security policy.  If the user is authorized by the policy,
                 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 policy is run to edit the
                       temporary files.  The sudoers policy uses the
                       SUDO_EDITOR, VISUAL and EDITOR environment variables (in
                       that order).  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.

                 To help prevent the editing of unauthorized files, the
                 following restrictions are enforced unless explicitly allowed
                 by the security policy:

                  o  Symbolic links may not be edited (version 1.8.15 and
                     higher).

                  o  Symbolic links along the path to be edited are not followed
                     when the parent directory is writable by the invoking user
                     unless that user is root (version 1.8.16 and higher).

                  o  Files located in a directory that is writable by the
                     invoking user may not be edited unless that user is root
                     (version 1.8.16 and higher).

                 Users are never allowed to edit device special files.

                 If the specified file does not exist, it will be created.
                 Unlike most commands run by sudo, the editor is run with the
                 invoking user's environment unmodified.  If the temporary file
                 becomes empty after editing, the user will be prompted before
                 it is installed.  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, --group=group
                 Run the command with the primary group set to group instead of
                 the primary group specified by the target user's password
                 database entry.  The group may be either a group name or a
                 numeric group-ID (GID) prefixed with the `#' character (e.g.,
                 `#0' for GID 0).  When running a command 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.  In either case, the primary group will be set to group.
                 The sudoers policy permits any of the target user's groups to
                 be specified via the -g option as long as the -P option is not
                 in use.

     -H, --set-home
                 Request that the security policy set the HOME environment
                 variable to the home directory specified by the target user's
                 password database entry.  Depending on the policy, this may be
                 the default behavior.

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

     -h host, --host=host
                 Run the command on the specified host if the security policy
                 plugin supports remote commands.  The sudoers plugin does not
                 currently support running remote commands.  This may also be
                 used in conjunction with the -l option to list a user's
                 privileges for the remote host.

     -i, --login
                 Run the shell specified by the target user's password database
                 entry as a login shell.  This means that login-specific
                 resource files such as .profile, .bash_profile, or .login will
                 be read by the shell.  If a command is specified, it is passed
                 to the shell as a simple command using the -c option.  The
                 command and any arguments are concatenated, separated by
                 spaces, after escaping each character (including white space)
                 with a backslash (`\') except for alphanumerics, underscores,
                 hyphens, and dollar signs.  If no command is specified, an
                 interactive shell is executed.  sudo attempts to change to that
                 user's home directory before running the shell.  The command is
                 run with an environment similar to the one a user would receive
                 at log in.  Most shells behave differently when a command is
                 specified as compared to an interactive session; consult the
                 shell's manual for details.  The Command environment section in
                 the sudoers(5) manual documents how the -i option affects the
                 environment in which a command is run when the sudoers policy
                 is in use.

     -K, --remove-timestamp
                 Similar to the -k option, except that it removes the user's
                 cached credentials entirely and may not be used in conjunction
                 with a command or other option.  This option does not require a
                 password.  Not all security policies support credential
                 caching.

     -k, --reset-timestamp
                 When used without a command, invalidates the user's cached
                 credentials.  In other words, 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, this option will cause sudo to ignore the
                 user's cached credentials.  As a result, sudo will prompt for a
                 password (if one is required by the security policy) and will
                 not update the user's cached credentials.

                 Not all security policies support credential caching.

     -l, --list  If no command is specified, list the allowed (and forbidden)
                 commands for the invoking user (or the user specified by the -U
                 option) on the current host.  A longer list format is used if
                 this option is specified multiple times and the security policy
                 supports a verbose output format.

                 If a command is specified and is permitted by the security
                 policy, the fully-qualified path to the command is displayed
                 along with any command line arguments.  If a command is
                 specified but not allowed by the policy, sudo will exit with a
                 status value of 1.

     -N, --no-update
                 Do not update the user's cached credentials, even if the user
                 successfully authenticates.  Unlike the -k flag, existing
                 cached credentials are used if they are valid.  To detect when
                 the user's cached credentials are valid (or when no
                 authentication is required), the following command can be used:
                       sudo -Nnv

                 Not all security policies support credential caching.

     -n, --non-interactive
                 Avoid prompting the user for input of any kind.  If a password
                 is required for the command to run, sudo will display an error
                 message and exit.

     -P, --preserve-groups
                 Preserve the invoking user's group vector unaltered.  By
                 default, the sudoers policy will initialize the group vector to
                 the list of groups the target user is a member of.  The real
                 and effective group-IDs, however, are still set to match the
                 target user.

     -p prompt, --prompt=prompt
                 Use a custom password prompt with optional escape sequences.
                 The following percent (`%') escape sequences are supported by
                 the sudoers policy:

                 %H  expanded to the host name including the domain name (only
                     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
                     specified)

                 %u  expanded to the invoking user's login name

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

                 The custom prompt will override the default prompt specified by
                 either the security policy or the SUDO_PROMPT environment
                 variable.  On systems that use PAM, the custom prompt will also
                 override the prompt specified by a PAM module unless the
                 passprompt_override flag is disabled in sudoers.

     -R directory, --chroot=directory
                 Change to the specified root directory (see chroot(8)) before
                 running the command.  The security policy may return an error
                 if the user does not have permission to specify the root
                 directory.

     -S, --stdin
                 Write the prompt to the standard error and read the password
                 from the standard input instead of using the terminal device.

     -s, --shell
                 Run the shell specified by the SHELL environment variable if it
                 is set or the shell specified by the invoking user's password
                 database entry.  If a command is specified, it is passed to the
                 shell as a simple command using the -c option.  The command and
                 any arguments are concatenated, separated by spaces, after
                 escaping each character (including white space) with a
                 backslash (`\') except for alphanumerics, underscores, hyphens,
                 and dollar signs.  If no command is specified, an interactive
                 shell is executed.  Most shells behave differently when a
                 command is specified as compared to an interactive session;
                 consult the shell's manual for details.

     -U user, --other-user=user
                 Used in conjunction with the -l option to list the privileges
                 for user instead of for the invoking user.  The security policy
                 may restrict listing other users' privileges.  When using the
                 sudoers policy, only root or a user with the ability to run any
                 command as either root or the specified user on the current
                 host may use this option.

     -T timeout, --command-timeout=timeout
                 Used to set a timeout for the command.  If the timeout expires
                 before the command has exited, the command will be terminated.
                 The security policy may restrict the ability to set command
                 timeouts.  The sudoers policy requires that user-specified
                 timeouts be explicitly enabled.

     -u user, --user=user
                 Run the command as a user other than the default target user
                 (usually root).  The user may be either a user name or a
                 numeric user-ID (UID) prefixed with the `#' character (e.g.,
                 `#0' for UID 0).  When running commands as a UID, many shells
                 require that the `#' be escaped with a backslash (`\').  Some
                 security policies may restrict UIDs to those listed in the
                 password database.  The sudoers policy allows UIDs that are not
                 in the password database as long as the targetpw option is not
                 set.  Other security policies may not support this.

     -V, --version
                 Print the sudo version string as well as the version string of
                 any configured plugins.  If the invoking user is already root,
                 the -V option will display the arguments passed to configure
                 when sudo was built; plugins may display additional information
                 such as default options.

     -v, --validate
                 Update the user's cached credentials, authenticating the user
                 if necessary.  For the sudoers plugin, this extends the sudo
                 timeout for another 5 minutes by default, but does not run a
                 command.  Not all security policies support cached credentials.

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

     Options that take a value may only be specified once unless otherwise
     indicated in the description.  This is to help guard against problems
     caused by poorly written scripts that invoke sudo with user-controlled
     input.

     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 restrictions imposed by the security policy plugin.  The
     sudoers policy subjects variables passed on the command line 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.


COMMAND EXECUTION

     When sudo executes a command, the security policy specifies the execution
     environment for the command.  Typically, the real and effective user and
     group and IDs 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).

     The following parameters may be specified by security policy:

     o  real and effective user-ID

     o  real and effective group-ID

     o  supplementary group-IDs

     o  the environment list

     o  current working directory

     o  file creation mode mask (umask)

     o  scheduling priority (aka nice value)

   Process model
     There are two distinct ways sudo can run a command.

     If an I/O logging plugin is configured or if the security policy explicitly
     requests it, a new pseudo-terminal ("pty") is allocated and fork(2) is used
     to create a second sudo process, referred to as the monitor.  The monitor
     creates a new terminal session with itself as the leader and the pty as its
     controlling terminal, calls fork(2), sets up the execution environment as
     described above, and then uses the execve(2) system call to run the command
     in the child process.  The monitor exists to relay job control signals
     between the user's existing terminal and the pty the command is being run
     in.  This makes it possible to suspend and resume the command.  Without the
     monitor, the command would be in what POSIX terms an "orphaned process
     group" and it would not receive any job control signals from the kernel.
     When the command exits or is terminated by a signal, the monitor passes the
     command's exit status to the main sudo process and exits.  After receiving
     the command's exit status, the main sudo passes the command's exit status
     to the security policy's close function and exits.

     If no pty is used, sudo calls fork(2), sets up the execution environment as
     described above, and uses the execve(2) system call to run the command in
     the child process.  The main sudo process waits until the command has
     completed, then passes the command's exit status to the security policy's
     close function and exits.  As a special case, if the policy plugin does not
     define a close function, sudo will execute the command directly instead of
     calling fork(2) first.  The sudoers policy plugin will only define a close
     function when I/O logging is enabled, a pty is required, an SELinux role is
     specified, the command has an associated timeout, or the pam_session or
     pam_setcred options are enabled.  Both pam_session and pam_setcred are
     enabled by default on systems using PAM.

     On systems that use PAM, the security policy's close function is
     responsible for closing the PAM session.  It may also log the command's
     exit status.

   Signal handling
     When the command is run as a child of the sudo process, sudo will relay
     signals it receives to the command.  The SIGINT and SIGQUIT signals are
     only relayed when the command is being run in a new pty or when the signal
     was sent by a user process, not the kernel.  This prevents the command from
     receiving SIGINT twice each time the user enters control-C.  Some signals,
     such as SIGSTOP and SIGKILL, cannot be caught and thus will not be relayed
     to the command.  As a general rule, SIGTSTP should be used instead of
     SIGSTOP when you wish to suspend a command being run by sudo.

     As a special case, sudo will not relay signals that were sent by the
     command it is running.  This prevents the command from accidentally killing
     itself.  On some systems, the reboot(8) command sends SIGTERM to all non-
     system processes other than itself before rebooting the system.  This
     prevents sudo from relaying the SIGTERM signal it received back to
     reboot(8), which might then exit before the system was actually rebooted,
     leaving it in a half-dead state similar to single user mode.  Note,
     however, that this check only applies to the command run by sudo and not
     any other processes that the command may create.  As a result, running a
     script that calls reboot(8) or shutdown(8) via sudo may cause the system to
     end up in this undefined state unless the reboot(8) or shutdown(8) are run
     using the exec() family of functions instead of system() (which interposes
     a shell between the command and the calling process).

     If no I/O logging plugins are loaded and the policy plugin has not defined
     a close() function, set a command timeout, or required that the command be
     run in a new pty, sudo may execute the command directly instead of running
     it as a child process.

   Plugins
     Plugins may be specified via Plugin directives in the sudo.conf(5) file.
     They may be loaded as dynamic shared objects (on systems that support
     them), or compiled directly into the sudo binary.  If no sudo.conf(5) file
     is present, or if it doesn't contain any Plugin lines, sudo will use
     sudoers(5) for the policy, auditing, and I/O logging plugins.  See the
     sudo.conf(5) manual for details of the /opt/local/etc/sudo.conf file and
     the sudo_plugin(5) manual for more information about the sudo plugin
     architecture.


EXIT VALUE

     Upon successful execution of a command, the exit status from sudo will be
     the exit status of the program that was executed.  If the command
     terminated due to receipt of a signal, sudo will send itself the same
     signal that terminated the command.

     If the -l option was specified without a command, sudo will exit with a
     value of 0 if the user is allowed to run sudo and they authenticated
     successfully (as required by the security policy).  If a command is
     specified with the -l option, the exit value will only be 0 if the command
     is permitted by the security policy, otherwise it will be 1.

     If there is an authentication failure, a configuration/permission problem,
     or if the given command cannot be executed, sudo exits with a value of 1.
     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 to the standard error.  (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.


SECURITY NOTES

     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).  Depending on the security policy, the user's PATH
     environment variable may be modified, replaced, or passed unchanged to the
     program that sudo executes.

     Users should never be granted sudo privileges to execute files that are
     writable by the user or that reside in a directory that is writable by the
     user.  If the user can modify or replace the command there is no way to
     limit what additional commands they can run.

     By default, sudo will 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 information on ways to address this, see the Preventing
     shell escapes section in sudoers(5).

     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).  This historical practice dates from a time
     when most operating systems allowed set-user-ID processes to dump core by
     default.  To aid in debugging sudo crashes, you may wish to re-enable core
     dumps by setting "disable_coredump" to false in the sudo.conf(5) file as
     follows:

         Set disable_coredump false

     See the sudo.conf(5) manual for more information.


ENVIRONMENT

     sudo utilizes the following environment variables.  The security policy has
     control over the actual content of the command's environment.

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

     MAIL             Set to the mail spool of the target user when the -i
                      option is specified, or when env_reset is enabled in
                      sudoers (unless MAIL is present in the env_keep list).

     HOME             Set to the home directory of the target user when the -i
                      or -H options are specified, when the -s option is
                      specified and set_home is set in sudoers, when
                      always_set_home is enabled in sudoers, or when env_reset
                      is enabled in sudoers and HOME is not present in the
                      env_keep list.

     LOGNAME          Set to the login name of the target user when the -i
                      option is specified, when the set_logname option is
                      enabled in sudoers, or when the env_reset option is
                      enabled in sudoers (unless LOGNAME is present in the
                      env_keep list).

     PATH             May be overridden by the security policy.

     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, including command line
                      arguments.  The command line arguments are truncated at
                      4096 characters to prevent a potential execution error.

     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 unless the -p option
                      was specified.

     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 same value as LOGNAME, described above.

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


FILES

     /opt/local/etc/sudo.conf  sudo front-end configuration


EXAMPLES

     The following examples assume a properly configured security policy.

     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:

         $ sudoedit -u www ~www/htdocs/index.html

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

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

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

         $ sudoedit -u jim -g audio ~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.  The
     commands are run in a sub-shell to allow the `cd' command and file
     redirection to work.

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


DIAGNOSTICS

     Error messages produced by sudo include:

     editing files in a writable directory is not permitted
           By default, sudoedit does not permit editing a file when any of the
           parent directories are writable by the invoking user.  This avoids a
           race condition that could allow the user to overwrite an arbitrary
           file.  See the sudoedit_checkdir option in sudoers(5) for more
           information.

     editing symbolic links is not permitted
           By default, sudoedit does not follow symbolic links when opening
           files.  See the sudoedit_follow option in sudoers(5) for more
           information.

     effective uid is not 0, is sudo installed setuid root?
           sudo was not run with root privileges.  The sudo binary must be owned
           by the root user and have the set-user-ID bit set.  Also, it must not
           be located on a file system mounted with the `nosuid' option or on an
           NFS file system that maps uid 0 to an unprivileged uid.

     effective uid is not 0, is sudo on a file system with the 'nosuid' option
           set or an NFS file system without root privileges?
           sudo was not run with root privileges.  The sudo binary has the
           proper owner and permissions but it still did not run with root
           privileges.  The most common reason for this is that the file system
           the sudo binary is located on is mounted with the `nosuid' option or
           it is an NFS file system that maps uid 0 to an unprivileged uid.

     fatal error, unable to load plugins
           An error occurred while loading or initializing the plugins specified
           in sudo.conf(5).

     invalid environment variable name
           One or more environment variable names specified via the -E option
           contained an equal sign (`=').  The arguments to the -E option should
           be environment variable names without an associated value.

     no password was provided
           When sudo tried to read the password, it did not receive any
           characters.  This may happen if no terminal is available (or the -S
           option is specified) and the standard input has been redirected from
           /dev/null.

     a terminal is required to read the password
           sudo needs to read the password but there is no mechanism available
           for it to do so.  A terminal is not present to read the password
           from, sudo has not been configured to read from the standard input,
           the -S option was not used, and no askpass helper has been specified
           either via the sudo.conf(5) file or the SUDO_ASKPASS environment
           variable.

     no writable temporary directory found
           sudoedit was unable to find a usable temporary directory in which to
           store its intermediate files.

     The "no new privileges" flag is set, which prevents sudo from running as
           root.
           sudo was run by a process that has the Linux "no new privileges" flag
           is set.  This causes the set-user-ID bit to be ignored when running
           an executable, which will prevent sudo from functioning.  The most
           likely cause for this is running sudo within a container that sets
           this flag.  Check the documentation to see if it is possible to
           configure the container such that the flag is not set.

     sudo must be owned by uid 0 and have the setuid bit set
           sudo was not run with root privileges.  The sudo binary does not have
           the correct owner or permissions.  It must be owned by the root user
           and have the set-user-ID bit set.

     sudoedit is not supported on this platform
           It is only possible to run sudoedit on systems that support setting
           the effective user-ID.

     timed out reading password
           The user did not enter a password before the password timeout (5
           minutes by default) expired.

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

     you may not specify environment variables in edit mode
           It is only possible to specify environment variables when running a
           command.  When editing a file, the editor is run with the user's
           environment unmodified.


SEE ALSO

     su(1), stat(2), login_cap(3), passwd(5), sudo.conf(5), sudo_plugin(5),
     sudo(8)


HISTORY

     See the HISTORY.md file in the sudo distribution
     (https://www.sudo.ws/about/history/) for a brief history of sudo.


AUTHORS

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

           Todd C. Miller

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


CAVEATS

     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 the sudoers(5) plugin's noexec functionality.

     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.  See the EXAMPLES section for more information.

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


BUGS

     If you believe you have found a bug in sudo, you can submit a bug report at
     https://bugzilla.sudo.ws/


SUPPORT

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


DISCLAIMER

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

Sudo 1.9.12                    September 13, 2022                    Sudo 1.9.12

sudo 1.9.12 - Generated Mon Oct 24 05:17:47 CDT 2022
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