sudo(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMAND EXECUTION | EXIT VALUE | SECURITY NOTES | ENVIRONMENT | FILES | EXAMPLES | DIAGNOSTICS | SEE ALSO | HISTORY | AUTHORS | CAVEATS | BUGS | SUPPORT | DISCLAIMER | COLOPHON

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

NAME         top

       sudo, sudoedit — execute a command as another user

SYNOPSIS         top

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

DESCRIPTION         top

       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.

       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 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 .  The policy may require that users authenticate
       themselves with a password or another authentication mechanism.
       If authentication is required, 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 5 minutes.

       Security policies may support credential caching to allow the
       user to run 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 with the -v option, a user can
       update the cached credentials without running a command.

       On systems where 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 .  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 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, 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 .  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, 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.
               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,
               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 args 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.  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 every
               cached credential for the user, regardless of the
               terminal or parent process ID.  The next time is run, a
               password must be entered if the security policy requires
               authentication.  It is not possible to use the -K option
               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 for the current session.  The next
               time is run in the session, a password must be entered if
               the security policy requires authentication.  By default,
               the sudoers policy uses a separate record in the
               credential cache for each terminal (or parent process ID
               if no terminal is present).  This prevents the -k option
               from interfering with commands run in a different
               terminal session.  See the timestamp_type option in
               sudoers(5) for more information.  This option does not
               require a password, and was added to allow a user to
               revoke permissions from a .logout file.

               When used in conjunction with a command or an option that
               may require a password, this option will cause to ignore
               the user's cached credentials.  As a result, 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 privileges 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 for the invoking user (or the, user
               specified by the -U option) on the current host, the
               fully-qualified path to the command is displayed along
               with any args. If -l is specified more than once (and the
               security policy supports it), the matching rule is
               displayed in a verbose format along with the command.  If
               a command is specified but not allowed by the policy,
               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
               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, 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 args 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, the -U option
               is restricted to the root user and users with either the
               “list” priviege for the specified user or the ability to
               run any command as root or user on the current host.

       -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
               user's ability to set 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 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 options passed to
               configure when 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 timeout for another 5 minutes by default, but does
               not run a command.  Not all security policies support
               cached credentials.

       --      The -- is used to delimit the end of the options.
               Subsequent options are passed to the command.

       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 as options to in the form VAR=value, for example
       LD_LIBRARY_PATH=/usr/local/pkg/lib.  Environment variables may be
       subject to restrictions imposed by the security policy plugin.
       The sudoers policy subjects environment variables passed as
       options to the same restrictions as existing environment
       variables with one important difference.  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         top

       When 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)

       scheduling priority (aka nice value)

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

       If an I/O logging plugin is configured to log terminal I/O, or if
       the security policy explicitly requests it, a new pseudo-terminal
       (“pty”) is allocated and fork(2) is used to create a second
       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) again, 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 terminal
       and the pty the command is being run in.  This makes it possible
       to suspend and resume the command normally.  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 process and
       exits.  After receiving the command's exit status, the main
       process passes the command's exit status to the security policy's
       close function, as well as the close function of any configured
       audit plugin, and exits.  This mode is the default for sudo
       versions 1.9.14 and above when using the sudoers policy.

       If no pty is used, 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 process
       waits until the command has completed, then passes the command's
       exit status to the security policy's close function, as well as
       the close function of any configured audit plugins, and exits.
       As a special case, if the policy plugin does not define a close
       function, 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.  This mode is the default for sudo versions prior to
       1.9.14 when using the sudoers policy.

       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 process, 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 .

       As a special case, 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)
       utility sends SIGTERM to all non-system processes other than
       itself before rebooting the system.  This prevents 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 and not any
       other processes that the command may create.  As a result,
       running a script that calls reboot(8) or shutdown(8) via 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).

   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
       binary.  If no sudo.conf(5) file is present, or if it doesn't
       contain any Plugin lines, 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 plugin architecture.

EXIT VALUE         top

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

       If the -l option was specified without a command, will exit with
       a value of 0 if the user is allowed to run 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, exits with a
       value of 1.  In the latter case, the error string is printed to
       the standard error.  If 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         top

       tries to be safe when executing external commands.

       To prevent command spoofing, 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
       executes.

       Users should never be granted 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, 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 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,
       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 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         top

       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 any
                        args. The args 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         top

       /etc/sudo.conf            front-end configuration

EXAMPLES         top

       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         top

       Error messages produced by 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?
             was not run with root privileges.  The 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?
             was not run with root privileges.  The 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 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 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
             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, 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.
             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 from
             functioning.  The most likely cause for this is running
             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
             was not run with root privileges.  The 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         top

       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         top

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

AUTHORS         top

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

             Todd C. Miller

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

CAVEATS         top

       There is no easy way to prevent a user from gaining a root shell
       if that user is allowed to run arbitrary commands via .  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.  The -D option can be used to run a command in
       a specific directory.

       Running shell scripts via 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         top

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

SUPPORT         top

       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         top

       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 or
       https://www.sudo.ws/about/license/ for complete details.

COLOPHON         top

       This page is part of the sudo (execute a command as another user)
       project.  Information about the project can be found at
       https://www.sudo.ws/.  If you have a bug report for this manual
       page, see ⟨https://bugzilla.sudo.ws/⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/sudo-project/sudo⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-21.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Sudo 1.9.15p4                August 9, 2023                      SUDO(8)

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