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NAME

       sudo, sudoedit — execute a command as another user

SYNOPSIS

       sudo -h | -K | -k | -V
       sudo -v [-ABknS] [-g group] [-h host] [-p prompt] [-u user]
       sudo -l [-ABknS] [-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] [-r role]
            [-t type] [-T timeout] [-u user] [VAR=value] [-i | -s] [command]
       sudoedit [-ABknS] [-C num] [-D directory] [-g group] [-h host]  [-p  prompt]  [-R  directory]  [-r  role]
            [-t type] [-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 /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  15  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 visudo(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.  Note that 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:

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

                     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).

                     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.  Note that 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.
                   Note that 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.  Note that 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, --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.

       -r role, --role=role
                   Run the command with an SELinux security context that includes the specified role.

       -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.   Note that most shells behave
                   differently when a command is specified as compared to an interactive  session;  consult  the
                   shell's manual for details.

       -t type, --type=type
                   Run  the  command  with  an SELinux security context that includes the specified type.  If no
                   type is specified, the default type is derived from the role.

       -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.  The
                   sudoers policy only allows root or a user with the ALL privilege on the current host  to  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 15 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:

         real and effective user-ID

         real and effective group-ID

         supplementary group-IDs

         the environment list

         current working directory

         file creation mode mask (umask)

         SELinux role and type

         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.   Note  that  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 /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.

       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 information on ways to address this, please 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

       /etc/sudo.conf            sudo front-end configuration

EXAMPLES

       Note: 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.  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"

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), sudoers(5), sudoers_timestamp(5),
       sudoreplay(8), visudo(8)

HISTORY

       See the HISTORY file in the sudo distribution (https://www.sudo.ws/history.html) 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  file  in  the  sudo  distribution  (https://www.sudo.ws/contributors.html) 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.   Please  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 feel you have found a bug in sudo, please submit a bug report at https://bugzilla.sudo.ws/

SUPPORT

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

DISCLAIMER

       sudo  is  provided  “AS  IS”  and  any  express or implied warranties, 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 https://www.sudo.ws/license.html for complete details.

Sudo 1.9.9                                      January 19, 2022                                         SUDO(8)