1SUDO(8) BSD System Manager's Manual SUDO(8)
2
4 sudo, sudoedit — execute a command as another user
5
7 sudo -h | -K | -k | -V
8 sudo -v [-ABknS] [-g group] [-h host] [-p prompt] [-u user]
9 sudo -l [-ABknS] [-g group] [-h host] [-p prompt] [-U user] [-u user]
10 [command]
11 sudo [-ABbEHnPS] [-C num] [-D directory] [-g group] [-h host] [-p prompt]
12 [-R directory] [-r role] [-t type] [-T timeout] [-u user]
13 [VAR=value] [-i | -s] [command]
14 sudoedit [-ABknS] [-C num] [-D directory] [-g group] [-h host]
15 [-p prompt] [-R directory] [-r role] [-t type] [-T timeout]
16 [-u user] file ...
17
19 sudo allows a permitted user to execute a command as the superuser or
20 another user, as specified by the security policy. The invoking user's
21 real (not effective) user-ID is used to determine the user name with
22 which to query the security policy.
23 sudo supports a plugin architecture for security policies and input/out‐
25 put logging. Third parties can develop and distribute their own policy
26 and I/O logging plugins to work seamlessly with the sudo front end. The
27 default security policy is sudoers, which is configured via the file
28 /etc/sudoers, or via LDAP. See the Plugins section for more information.
29 The security policy determines what privileges, if any, a user has to run
31 sudo. The policy may require that users authenticate themselves with a
32 password or another authentication mechanism. If authentication is
33 required, sudo will exit if the user's password is not entered within a
34 configurable time limit. This limit is policy-specific; the default
35 password prompt timeout for the sudoers security policy is 5 minutes.
36 Security policies may support credential caching to allow the user to run
38 sudo again for a period of time without requiring authentication. By
39 default, the sudoers policy caches credentials on a per-terminal basis
40 for 5 minutes. See the timestamp_type and timestamp_timeout options in
41 sudoers(5) for more information. By running sudo with the -v option, a
42 user can update the cached credentials without running a command.
43 On systems where sudo is the primary method of gaining superuser privi‐
45 leges, it is imperative to avoid syntax errors in the security policy
46 configuration files. For the default security policy, sudoers(5),
47 changes to the configuration files should be made using the visudo(8)
48 utility which will ensure that no syntax errors are introduced.
49 When invoked as sudoedit, the -e option (described below), is implied.
51 Security policies may log successful and failed attempts to use sudo. If
53 an I/O plugin is configured, the running command's input and output may
54 be logged as well.
55 The options are as follows:
57 -A, --askpass
59 Normally, if sudo requires a password, it will read it from
60 the user's terminal. If the -A (askpass) option is speci‐
61 fied, a (possibly graphical) helper program is executed to
62 read the user's password and output the password to the stan‐
63 dard output. If the SUDO_ASKPASS environment variable is
64 set, it specifies the path to the helper program. Otherwise,
65 if sudo.conf(5) contains a line specifying the askpass pro‐
66 gram, that value will be used. For example:
67 # Path to askpass helper program
69 Path askpass /usr/X11R6/bin/ssh-askpass
70 If no askpass program is available, sudo will exit with an
72 error.
73 -B, --bell Ring the bell as part of the password promp when a terminal
75 is present. This option has no effect if an askpass program
76 is used.
77 -b, --background
79 Run the given command in the background. Note that it is not
80 possible to use shell job control to manipulate background
81 processes started by sudo. Most interactive commands will
82 fail to work properly in background mode.
83 -C num, --close-from=num
85 Close all file descriptors greater than or equal to num
86 before executing a command. Values less than three are not
87 permitted. By default, sudo will close all open file
88 descriptors other than standard input, standard output and
89 standard error when executing a command. The security policy
90 may restrict the user's ability to use this option. The
91 sudoers policy only permits use of the -C option when the
92 administrator has enabled the closefrom_override option.
93 -D directory, --chdir=directory
95 Run the command in the specified directory instead of the
96 current working directory. The security policy may return an
97 error if the user does not have permission to specify the
98 working directory.
99 -E, --preserve-env
101 Indicates to the security policy that the user wishes to pre‐
102 serve their existing environment variables. The security
103 policy may return an error if the user does not have permis‐
104 sion to preserve the environment.
105 --preserve-env=list
107 Indicates to the security policy that the user wishes to add
108 the comma-separated list of environment variables to those
109 preserved from the user's environment. The security policy
110 may return an error if the user does not have permission to
111 preserve the environment. This option may be specified mul‐
112 tiple times.
113 -e, --edit Edit one or more files instead of running a command. In lieu
115 of a path name, the string "sudoedit" is used when consulting
116 the security policy. If the user is authorized by the pol‐
117 icy, the following steps are taken:
118 1. Temporary copies are made of the files to be edited with
120 the owner set to the invoking user.
121 2. The editor specified by the policy is run to edit the
123 temporary files. The sudoers policy uses the
124 SUDO_EDITOR, VISUAL and EDITOR environment variables (in
125 that order). If none of SUDO_EDITOR, VISUAL or EDITOR
126 are set, the first program listed in the editor
127 sudoers(5) option is used.
128 3. If they have been modified, the temporary files are
130 copied back to their original location and the temporary
131 versions are removed.
132 To help prevent the editing of unauthorized files, the fol‐
134 lowing restrictions are enforced unless explicitly allowed by
135 the security policy:
136 · Symbolic links may not be edited (version 1.8.15 and
138 higher).
139 · Symbolic links along the path to be edited are not fol‐
141 lowed when the parent directory is writable by the invok‐
142 ing user unless that user is root (version 1.8.16 and
143 higher).
144 · Files located in a directory that is writable by the
146 invoking user may not be edited unless that user is root
147 (version 1.8.16 and higher).
148 Users are never allowed to edit device special files.
150 If the specified file does not exist, it will be created.
152 Note that unlike most commands run by sudo, the editor is run
153 with the invoking user's environment unmodified. If the tem‐
154 porary file becomes empty after editing, the user will be
155 prompted before it is installed. If, for some reason, sudo
156 is unable to update a file with its edited version, the user
157 will receive a warning and the edited copy will remain in a
158 temporary file.
159 -g group, --group=group
161 Run the command with the primary group set to group instead
162 of the primary group specified by the target user's password
163 database entry. The group may be either a group name or a
164 numeric group-ID (GID) prefixed with the ‘#’ character (e.g.,
165 #0 for GID 0). When running a command as a GID, many shells
166 require that the ‘#’ be escaped with a backslash (‘\’). If
167 no -u option is specified, the command will be run as the
168 invoking user. In either case, the primary group will be set
169 to group. The sudoers policy permits any of the target
170 user's groups to be specified via the -g option as long as
171 the -P option is not in use.
172 -H, --set-home
174 Request that the security policy set the HOME environment
175 variable to the home directory specified by the target user's
176 password database entry. Depending on the policy, this may
177 be the default behavior.
178 -h, --help Display a short help message to the standard output and exit.
180 -h host, --host=host
182 Run the command on the specified host if the security policy
183 plugin supports remote commands. Note that the sudoers plug‐
184 in does not currently support running remote commands. This
185 may also be used in conjunction with the -l option to list a
186 user's privileges for the remote host.
187 -i, --login
189 Run the shell specified by the target user's password data‐
190 base entry as a login shell. This means that login-specific
191 resource files such as .profile, .bash_profile or .login will
192 be read by the shell. If a command is specified, it is
193 passed to the shell for execution via the shell's -c option.
194 If no command is specified, an interactive shell is executed.
195 sudo attempts to change to that user's home directory before
196 running the shell. The command is run with an environment
197 similar to the one a user would receive at log in. Note that
198 most shells behave differently when a command is specified as
199 compared to an interactive session; consult the shell's man‐
200 ual for details. The Command environment section in the
201 sudoers(5) manual documents how the -i option affects the
202 environment in which a command is run when the sudoers policy
203 is in use.
204 -K, --remove-timestamp
206 Similar to the -k option, except that it removes the user's
207 cached credentials entirely and may not be used in conjunc‐
208 tion with a command or other option. This option does not
209 require a password. Not all security policies support cre‐
210 dential caching.
211 -k, --reset-timestamp
213 When used without a command, invalidates the user's cached
214 credentials. In other words, the next time sudo is run a
215 password will be required. This option does not require a
216 password and was added to allow a user to revoke sudo permis‐
217 sions from a .logout file.
218 When used in conjunction with a command or an option that may
220 require a password, this option will cause sudo to ignore the
221 user's cached credentials. As a result, sudo will prompt for
222 a password (if one is required by the security policy) and
223 will not update the user's cached credentials.
224 Not all security policies support credential caching.
226 -l, --list If no command is specified, list the allowed (and forbidden)
228 commands for the invoking user (or the user specified by the
229 -U option) on the current host. A longer list format is used
230 if this option is specified multiple times and the security
231 policy supports a verbose output format.
232 If a command is specified and is permitted by the security
234 policy, the fully-qualified path to the command is displayed
235 along with any command line arguments. If a command is spec‐
236 ified but not allowed by the policy, sudo will exit with a
237 status value of 1.
238 -n, --non-interactive
240 Avoid prompting the user for input of any kind. If a pass‐
241 word is required for the command to run, sudo will display an
242 error message and exit.
243 -P, --preserve-groups
245 Preserve the invoking user's group vector unaltered. By
246 default, the sudoers policy will initialize the group vector
247 to the list of groups the target user is a member of. The
248 real and effective group-IDs, however, are still set to match
249 the target user.
250 -p prompt, --prompt=prompt
252 Use a custom password prompt with optional escape sequences.
253 The following percent (‘%’) escape sequences are supported by
254 the sudoers policy:
255 %H expanded to the host name including the domain name (on
257 if the machine's host name is fully qualified or the fqdn
258 option is set in sudoers(5))
259 %h expanded to the local host name without the domain name
261 %p expanded to the name of the user whose password is being
263 requested (respects the rootpw, targetpw, and runaspw
264 flags in sudoers(5))
265 %U expanded to the login name of the user the command will
267 be run as (defaults to root unless the -u option is also
268 specified)
269 %u expanded to the invoking user's login name
271 %% two consecutive ‘%’ characters are collapsed into a sin‐
273 gle ‘%’ character
274 The custom prompt will override the default prompt specified
276 by either the security policy or the SUDO_PROMPT environment
277 variable. On systems that use PAM, the custom prompt will
278 also override the prompt specified by a PAM module unless the
279 passprompt_override flag is disabled in sudoers.
280 -R directory, --chroot=directory
282 Change to the specified root directory (see chroot(8)) before
283 running the command. The security policy may return an error
284 if the user does not have permission to specify the root
285 directory.
286 -r role, --role=role
288 Run the command with an SELinux security context that
289 includes the specified role.
290 -S, --stdin
292 Write the prompt to the standard error and read the password
293 from the standard input instead of using the terminal device.
294 -s, --shell
296 Run the shell specified by the SHELL environment variable if
297 it is set or the shell specified by the invoking user's pass‐
298 word database entry. If a command is specified, it is passed
299 to the shell for execution via the shell's -c option. If no
300 command is specified, an interactive shell is executed. Note
301 that most shells behave differently when a command is speci‐
302 fied as compared to an interactive session; consult the
303 shell's manual for details.
304 -t type, --type=type
306 Run the command with an SELinux security context that
307 includes the specified type. If no type is specified, the
308 default type is derived from the role.
309 -U user, --other-user=user
311 Used in conjunction with the -l option to list the privileges
312 for user instead of for the invoking user. The security pol‐
313 icy may restrict listing other users' privileges. The
314 sudoers policy only allows root or a user with the ALL privi‐
315 lege on the current host to use this option.
316 -T timeout, --command-timeout=timeout
318 Used to set a timeout for the command. If the timeout
319 expires before the command has exited, the command will be
320 terminated. The security policy may restrict the ability to
321 set command timeouts. The sudoers policy requires that user-
322 specified timeouts be explicitly enabled.
323 -u user, --user=user
325 Run the command as a user other than the default target user
326 (usually root). The user may be either a user name or a
327 numeric user-ID (UID) prefixed with the ‘#’ character (e.g.,
328 #0 for UID 0). When running commands as a UID, many shells
329 require that the ‘#’ be escaped with a backslash (‘\’). Some
330 security policies may restrict UIDs to those listed in the
331 password database. The sudoers policy allows UIDs that are
332 not in the password database as long as the targetpw option
333 is not set. Other security policies may not support this.
334 -V, --version
336 Print the sudo version string as well as the version string
337 of the security policy plugin and any I/O plugins. If the
338 invoking user is already root the -V option will display the
339 arguments passed to configure when sudo was built and plugins
340 may display more verbose information such as default options.
341 -v, --validate
343 Update the user's cached credentials, authenticating the user
344 if necessary. For the sudoers plugin, this extends the sudo
345 timeout for another 5 minutes by default, but does not run a
346 command. Not all security policies support cached creden‐
347 tials.
348 -- The -- option indicates that sudo should stop processing com‐
350 mand line arguments.
351 Options that take a value may only be specified once unless otherwise
353 indicated in the description. This is to help guard against problems
354 caused by poorly written scripts that invoke sudo with user-controlled
355 input.
356 Environment variables to be set for the command may also be passed on the
358 command line in the form of VAR=value, e.g.,
359 LD_LIBRARY_PATH=/usr/local/pkg/lib. Variables passed on the command line
360 are subject to restrictions imposed by the security policy plugin. The
361 sudoers policy subjects variables passed on the command line to the same
362 restrictions as normal environment variables with one important excep‐
363 tion. If the setenv option is set in sudoers, the command to be run has
364 the SETENV tag set or the command matched is ALL, the user may set vari‐
365 ables that would otherwise be forbidden. See sudoers(5) for more infor‐
366 mation.
367
369 When sudo executes a command, the security policy specifies the execution
370 environment for the command. Typically, the real and effective user and
371 group and IDs are set to match those of the target user, as specified in
372 the password database, and the group vector is initialized based on the
373 group database (unless the -P option was specified).
374 The following parameters may be specified by security policy:
376 · real and effective user-ID
378 · real and effective group-ID
380 · supplementary group-IDs
382 · the environment list
384 · current working directory
386 · file creation mode mask (umask)
388 · SELinux role and type
390 · scheduling priority (aka nice value)
392 Process model
394 There are two distinct ways sudo can run a command.
395 If an I/O logging plugin is configured or if the security policy explic‐
397 itly requests it, a new pseudo-terminal (“pty”) is allocated and fork(2)
398 is used to create a second sudo process, referred to as the monitor. The
399 monitor creates a new terminal session with itself as the leader and the
400 pty as its controlling terminal, calls fork(2), sets up the execution
401 environment as described above, and then uses the execve(2) system call
402 to run the command in the child process. The monitor exists to relay job
403 control signals between the user's existing terminal and the pty the com‐
404 mand is being run in. This makes it possible to suspend and resume the
405 command. Without the monitor, the command would be in what POSIX terms
406 an “orphaned process group” and it would not receive any job control sig‐
407 nals from the kernel. When the command exits or is terminated by a sig‐
408 nal, the monitor passes the command's exit status to the main sudo
409 process and exits. After receiving the command's exit status, the main
410 sudo passes the command's exit status to the security policy's close
411 function and exits.
412 If no pty is used, sudo calls fork(2), sets up the execution environment
414 as described above, and uses the execve(2) system call to run the command
415 in the child process. The main sudo process waits until the command has
416 completed, then passes the command's exit status to the security policy's
417 close function and exits. As a special case, if the policy plugin does
418 not define a close function, sudo will execute the command directly
419 instead of calling fork(2) first. The sudoers policy plugin will only
420 define a close function when I/O logging is enabled, a pty is required,
421 or the pam_session or pam_setcred options are enabled. Note that
422 pam_session and pam_setcred are enabled by default on systems using PAM.
423 On systems that use PAM, the security policy's close function is respon‐
425 sible for closing the PAM session. It may also log the command's exit
426 status.
427 Signal handling
429 When the command is run as a child of the sudo process, sudo will relay
430 signals it receives to the command. The SIGINT and SIGQUIT signals are
431 only relayed when the command is being run in a new pty or when the sig‐
432 nal was sent by a user process, not the kernel. This prevents the com‐
433 mand from receiving SIGINT twice each time the user enters control-C.
434 Some signals, such as SIGSTOP and SIGKILL, cannot be caught and thus will
435 not be relayed to the command. As a general rule, SIGTSTP should be used
436 instead of SIGSTOP when you wish to suspend a command being run by sudo.
437 As a special case, sudo will not relay signals that were sent by the com‐
439 mand it is running. This prevents the command from accidentally killing
440 itself. On some systems, the reboot(8) command sends SIGTERM to all non-
441 system processes other than itself before rebooting the system. This
442 prevents sudo from relaying the SIGTERM signal it received back to
443 reboot(8), which might then exit before the system was actually rebooted,
444 leaving it in a half-dead state similar to single user mode. Note, how‐
445 ever, that this check only applies to the command run by sudo and not any
446 other processes that the command may create. As a result, running a
447 script that calls reboot(8) or shutdown(8) via sudo may cause the system
448 to end up in this undefined state unless the reboot(8) or shutdown(8) are
449 run using the exec() family of functions instead of system() (which
450 interposes a shell between the command and the calling process).
451 If no I/O logging plugins are loaded and the policy plugin has not
453 defined a close() function, set a command timeout or required that the
454 command be run in a new pty, sudo may execute the command directly
455 instead of running it as a child process.
456 Plugins
458 Plugins may be specified via Plugin directives in the sudo.conf(5) file.
459 They may be loaded as dynamic shared objects (on systems that support
460 them), or compiled directly into the sudo binary. If no sudo.conf(5)
461 file is present, or if it doesn't contain any Plugin lines, sudo will use
462 sudoers(5) for the policy, auditing and I/O logging plugins. See the
463 sudo.conf(5) manual for details of the /etc/sudo.conf file and the
464 sudo_plugin(5) manual for more information about the sudo plugin archi‐
465 tecture.
466
468 Upon successful execution of a command, the exit status from sudo will be
469 the exit status of the program that was executed. If the command termi‐
470 nated due to receipt of a signal, sudo will send itself the same signal
471 that terminated the command.
472 If the -l option was specified without a command, sudo will exit with a
474 value of 0 if the user is allowed to run sudo and they authenticated suc‐
475 cessfully (as required by the security policy). If a command is speci‐
476 fied with the -l option, the exit value will only be 0 if the command is
477 permitted by the security policy, otherwise it will be 1.
478 If there is an authentication failure, a configuration/permission problem
480 or if the given command cannot be executed, sudo exits with a value of 1.
481 In the latter case, the error string is printed to the standard error.
482 If sudo cannot stat(2) one or more entries in the user's PATH, an error
483 is printed to the standard error. (If the directory does not exist or if
484 it is not really a directory, the entry is ignored and no error is
485 printed.) This should not happen under normal circumstances. The most
486 common reason for stat(2) to return “permission denied” is if you are
487 running an automounter and one of the directories in your PATH is on a
488 machine that is currently unreachable.
489
491 sudo tries to be safe when executing external commands.
492 To prevent command spoofing, sudo checks "." and "" (both denoting cur‐
494 rent directory) last when searching for a command in the user's PATH (if
495 one or both are in the PATH). Note, however, that the actual PATH envi‐
496 ronment variable is not modified and is passed unchanged to the program
497 that sudo executes.
498 Users should never be granted sudo privileges to execute files that are
500 writable by the user or that reside in a directory that is writable by
501 the user. If the user can modify or replace the command there is no way
502 to limit what additional commands they can run.
503 Please note that sudo will normally only log the command it explicitly
505 runs. If a user runs a command such as sudo su or sudo sh, subsequent
506 commands run from that shell are not subject to sudo's security policy.
507 The same is true for commands that offer shell escapes (including most
508 editors). If I/O logging is enabled, subsequent commands will have their
509 input and/or output logged, but there will not be traditional logs for
510 those commands. Because of this, care must be taken when giving users
511 access to commands via sudo to verify that the command does not inadver‐
512 tently give the user an effective root shell. For more information,
513 please see the Preventing shell escapes section in sudoers(5).
514 To prevent the disclosure of potentially sensitive information, sudo dis‐
516 ables core dumps by default while it is executing (they are re-enabled
517 for the command that is run). This historical practice dates from a time
518 when most operating systems allowed set-user-ID processes to dump core by
519 default. To aid in debugging sudo crashes, you may wish to re-enable
520 core dumps by setting “disable_coredump” to false in the sudo.conf(5)
521 file as follows:
522 Set disable_coredump false
524 See the sudo.conf(5) manual for more information.
526
528 sudo utilizes the following environment variables. The security policy
529 has control over the actual content of the command's environment.
530 EDITOR Default editor to use in -e (sudoedit) mode if neither
532 SUDO_EDITOR nor VISUAL is set.
533 MAIL Set to the mail spool of the target user when the -i
535 option is specified or when env_reset is enabled in
536 sudoers (unless MAIL is present in the env_keep list).
537 HOME Set to the home directory of the target user when the -i
539 or -H options are specified, when the -s option is spec‐
540 ified and set_home is set in sudoers, when
541 always_set_home is enabled in sudoers, or when env_reset
542 is enabled in sudoers and HOME is not present in the
543 env_keep list.
544 LOGNAME Set to the login name of the target user when the -i
546 option is specified, when the set_logname option is
547 enabled in sudoers or when the env_reset option is
548 enabled in sudoers (unless LOGNAME is present in the
549 env_keep list).
550 PATH May be overridden by the security policy.
552 SHELL Used to determine shell to run with -s option.
554 SUDO_ASKPASS Specifies the path to a helper program used to read the
556 password if no terminal is available or if the -A option
557 is specified.
558 SUDO_COMMAND Set to the command run by sudo, including command line
560 arguments. The command line arguments are truncated at
561 4096 characters to prevent a potential execution error.
562 SUDO_EDITOR Default editor to use in -e (sudoedit) mode.
564 SUDO_GID Set to the group-ID of the user who invoked sudo.
566 SUDO_PROMPT Used as the default password prompt unless the -p option
568 was specified.
569 SUDO_PS1 If set, PS1 will be set to its value for the program
571 being run.
572 SUDO_UID Set to the user-ID of the user who invoked sudo.
574 SUDO_USER Set to the login name of the user who invoked sudo.
576 USER Set to the same value as LOGNAME, described above.
578 VISUAL Default editor to use in -e (sudoedit) mode if
580 SUDO_EDITOR is not set.
581
583 /etc/sudo.conf sudo front end configuration
584
586 Note: the following examples assume a properly configured security pol‐
587 icy.
588 To get a file listing of an unreadable directory:
590 $ sudo ls /usr/local/protected
592 To list the home directory of user yaz on a machine where the file system
594 holding ~yaz is not exported as root:
595 $ sudo -u yaz ls ~yaz
597 To edit the index.html file as user www:
599 $ sudoedit -u www ~www/htdocs/index.html
601 To view system logs only accessible to root and users in the adm group:
603 $ sudo -g adm more /var/log/syslog
605 To run an editor as jim with a different primary group:
607 $ sudoedit -u jim -g audio ~jim/sound.txt
609 To shut down a machine:
611 $ sudo shutdown -r +15 "quick reboot"
613 To make a usage listing of the directories in the /home partition. Note
615 that this runs the commands in a sub-shell to make the cd and file redi‐
616 rection work.
617 $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
619
621 Error messages produced by sudo include:
622 editing files in a writable directory is not permitted
624 By default, sudoedit does not permit editing a file when any of the
625 parent directories are writable by the invoking user. This avoids
626 a race condition that could allow the user to overwrite an arbi‐
627 trary file. See the sudoedit_checkdir option in sudoers(5) for
628 more information.
629 editing symbolic links is not permitted
631 By default, sudoedit does not follow symbolic links when opening
632 files. See the sudoedit_follow option in sudoers(5) for more
633 information.
634 effective uid is not 0, is sudo installed setuid root?
636 sudo was not run with root privileges. The sudo binary must be
637 owned by the root user and have the set-user-ID bit set. Also, it
638 must not be located on a file system mounted with the ‘nosuid’
639 option or on an NFS file system that maps uid 0 to an unprivileged
640 uid.
641 effective uid is not 0, is sudo on a file system with the 'nosuid' option
643 set or an NFS file system without root privileges?
644 sudo was not run with root privileges. The sudo binary has the
645 proper owner and permissions but it still did not run with root
646 privileges. The most common reason for this is that the file sys‐
647 tem the sudo binary is located on is mounted with the ‘nosuid’
648 option or it is an NFS file system that maps uid 0 to an unprivi‐
649 leged uid.
650 fatal error, unable to load plugins
652 An error occurred while loading or initializing the plugins speci‐
653 fied in sudo.conf(5).
654 invalid environment variable name
656 One or more environment variable names specified via the -E option
657 contained an equal sign (‘=’). The arguments to the -E option
658 should be environment variable names without an associated value.
659 no password was provided
661 When sudo tried to read the password, it did not receive any char‐
662 acters. This may happen if no terminal is available (or the -S
663 option is specified) and the standard input has been redirected
664 from /dev/null.
665 a terminal is required to read the password
667 sudo needs to read the password but there is no mechanism available
668 for it to do so. A terminal is not present to read the password
669 from, sudo has not been configured to read from the standard input,
670 the -S option was not used, and no askpass helper has been speci‐
671 fied either via the sudo.conf(5) file or the SUDO_ASKPASS environ‐
672 ment variable.
673 no writable temporary directory found
675 sudoedit was unable to find a usable temporary directory in which
676 to store its intermediate files.
677 sudo must be owned by uid 0 and have the setuid bit set
679 sudo was not run with root privileges. The sudo binary does not
680 have the correct owner or permissions. It must be owned by the
681 root user and have the set-user-ID bit set.
682 sudoedit is not supported on this platform
684 It is only possible to run sudoedit on systems that support setting
685 the effective user-ID.
686 timed out reading password
688 The user did not enter a password before the password timeout (5
689 minutes by default) expired.
690 you do not exist in the passwd database
692 Your user-ID does not appear in the system passwd database.
693 you may not specify environment variables in edit mode
695 It is only possible to specify environment variables when running a
696 command. When editing a file, the editor is run with the user's
697 environment unmodified.
698
700 su(1), stat(2), login_cap(3), passwd(5), sudo.conf(5), sudo_plugin(5),
701 sudoers(5), sudoers_timestamp(5), sudoreplay(8), visudo(8)
702
704 See the HISTORY file in the sudo distribution (https://www.sudo.ws/his‐
705 tory.html) for a brief history of sudo.
706
708 Many people have worked on sudo over the years; this version consists of
709 code written primarily by:
710 Todd C. Miller
712 See the CONTRIBUTORS file in the sudo distribution
714 (https://www.sudo.ws/contributors.html) for an exhaustive list of people
715 who have contributed to sudo.
716
718 There is no easy way to prevent a user from gaining a root shell if that
719 user is allowed to run arbitrary commands via sudo. Also, many programs
720 (such as editors) allow the user to run commands via shell escapes, thus
721 avoiding sudo's checks. However, on most systems it is possible to pre‐
722 vent shell escapes with the sudoers(5) plugin's noexec functionality.
723 It is not meaningful to run the cd command directly via sudo, e.g.,
725 $ sudo cd /usr/local/protected
727 since when the command exits the parent process (your shell) will still
729 be the same. Please see the EXAMPLES section for more information.
730 Running shell scripts via sudo can expose the same kernel bugs that make
732 set-user-ID shell scripts unsafe on some operating systems (if your OS
733 has a /dev/fd/ directory, set-user-ID shell scripts are generally safe).
734
736 If you feel you have found a bug in sudo, please submit a bug report at
737 https://bugzilla.sudo.ws/
738
740 Limited free support is available via the sudo-users mailing list, see
741 https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
742 the archives.
743
745 sudo is provided “AS IS” and any express or implied warranties, includ‐
746 ing, but not limited to, the implied warranties of merchantability and
747 fitness for a particular purpose are disclaimed. See the LICENSE file
748 distributed with sudo or https://www.sudo.ws/license.html for complete
749 details.
750Sudo 1.9.5p2 September 1, 2020 Sudo 1.9.5p2