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

DESCRIPTION         top

     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 and in‐
     put/output logging.  Third parties can develop and distribute their own
     policy and I/O logging 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 5
     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 ba‐
     sis for 5 minutes.  See the timestamp_type and timestamp_timeout op‐
     tions 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 privi‐
     leges, 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 may log successful and failed attempts to use 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 speci‐
                 fied, 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.  Oth‐
                 erwise, 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 promp when a terminal
                 is present.  This option has no effect if an askpass pro‐
                 gram is used.

     -b, --background
                 Run the given command in the background.  Note that it is
                 not possible to use shell job control to manipulate back‐
                 ground processes started by sudo.  Most interactive com‐
                 mands will fail to work properly in background mode.

     -C num, --close-from=num
                 Close all file descriptors greater than or equal to num be‐
                 fore executing a command.  Values less than three are not
                 permitted.  By default, sudo will close all open file de‐
                 scriptors other than standard input, standard output and
                 standard error when executing a command.  The security pol‐
                 icy 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 op‐
                 tion.

     -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 secu‐
                 rity 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 per‐
                 mission 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 tempo‐
                      rary versions are removed.

                 To help prevent the editing of unauthorized files, the fol‐
                 lowing 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 fol‐
                    lowed when the parent directory is writable by the in‐
                    voking user unless that user is root (version 1.8.16 and
                    higher).

                 Files located in a directory that is writable by the in‐
                    voking 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 rea‐
                 son, sudo is unable to update a file with its edited ver‐
                 sion, 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 pass‐
                 word 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 back‐
                 slash (‘\’).  If no -u option is specified, the command
                 will be run as the invoking user.  In either case, the pri‐
                 mary group will be set to group.  The sudoers policy per‐
                 mits 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 pol‐
                 icy 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 data‐
                 base entry as a login shell.  This means that login-spe‐
                 cific resource files such as .profile, .bash_profile or
                 .login will be read by the shell.  If a command is speci‐
                 fied, it is passed to the shell for execution via the
                 shell's -c option.  If no command is specified, an interac‐
                 tive shell is executed.  sudo attempts to change to that
                 user's home directory before running the shell.  The com‐
                 mand is run with an environment similar to the one a user
                 would receive at log in.  Note that most shells behave dif‐
                 ferently when a command is specified as compared to an in‐
                 teractive 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 conjunc‐
                 tion with a command or other option.  This option does not
                 require a password.  Not all security policies support cre‐
                 dential 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 per‐
                 missions 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 ig‐
                 nore 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 forbid‐
                 den) commands for the invoking user (or the user specified
                 by the -U option) on the current host.  A longer list for‐
                 mat 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 dis‐
                 played 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 pass‐
                 word 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 vec‐
                 tor 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 se‐
                 quences.  The following percent (‘%’) escape sequences are
                 supported by the sudoers policy:

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

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

                 %p  expanded to the name of the user whose password is be‐
                     ing 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 speci‐
                 fied by either the security policy or the SUDO_PROMPT envi‐
                 ronment 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)) be‐
                 fore 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 pass‐
                 word 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 for execution via the shell's -c op‐
                 tion.  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.

     -U user, --other-user=user
                 Used in conjunction with the -l option to list the privi‐
                 leges for user instead of for the invoking user.  The secu‐
                 rity 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 ex‐
                 pires 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 the security policy plugin and any I/O plugins.  If the
                 invoking user is already root the -V option will display
                 the arguments passed to configure when sudo was built and
                 plugins may display more verbose information such as de‐
                 fault 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         top

     When sudo executes a command, the security policy specifies the execu‐
     tion 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 sudo can run a command.

     If an I/O logging plugin is configured or if the security policy ex‐
     plicitly 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 possi‐
     ble to suspend and resume the command.  Without the monitor, the com‐
     mand 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 com‐
     mand'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 sta‐
     tus to the security policy's close function and exits.

     If no pty is used, sudo calls fork(2), sets up the execution environ‐
     ment 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 se‐
     curity 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, 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 re‐
     sponsible 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 sys‐
     tem.  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 de‐
     fined a close() function, set a command timeout or required that the
     command be run in a new pty, sudo may execute the command directly in‐
     stead 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 log‐
     ging 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         top

     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 com‐
     mand is permitted by the security policy, otherwise it will be 1.

     If there is an authentication failure, a configuration/permission prob‐
     lem 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         top

     sudo tries to be safe when executing external commands.

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

     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 giv‐
     ing users access to commands via sudo to verify that the command does
     not inadvertently give the user an effective root shell.  For more in‐
     formation, 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-en‐
     abled 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         top

     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 en‐
                      abled 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 op‐
                      tion 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            sudo front end configuration

EXAMPLES         top

     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         top

     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 in‐
           formation.

     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 unprivi‐
           leged 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 unprivi‐
           leged uid.

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

     invalid environment variable name
           One or more environment variable names specified via the -E op‐
           tion contained an equal sign (‘=’).  The arguments to the -E op‐
           tion 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 redi‐
           rected from /dev/null.

     a terminal is required to read the password
           sudo needs to read the password but there is no mechanism avail‐
           able 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.

     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 set‐
           ting 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 file in the sudo distribution (https://www.sudo.ws/his‐
     tory.html) for a brief history of sudo.

AUTHORS         top

     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 peo‐
     ple who have contributed to sudo.

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 sudo.  Also, many
     programs (such as editors) allow the user to run commands via shell es‐
     capes, 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 gener‐
     ally safe).

BUGS         top

     If you feel you have found a bug in sudo, please 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

     sudo is provided “AS IS” and any express or implied warranties, includ‐
     ing, 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.

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 2020-11-01.  (At that time,
     the date of the most recent commit that was found in the repository was
     2020-10-30.)  If you discover any rendering problems in this HTML ver‐
     sion 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 in‐
     formation in this COLOPHON (which is not part of the original manual
     page), send a mail to man-pages@man7.org

Sudo 1.9.3p1                  September 1, 2020                 Sudo 1.9.3p1

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