4 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
8 sudo, sudoedit - execute a command as another user
10 S
\bSY
\bYN
\bNO
\bOP
\bPS
\bSI
\bIS
\bS
11 s
\bsu
\bud
\bdo
\bo [-
\b-n
\bn] -
\b-h
\bh | -
\b-K
\bK | -
\b-k
\bk | -
\b-L
\bL | -
\b-V
\bV | -
\b-v
\bv
13 s
\bsu
\bud
\bdo
\bo -
\b-l
\bl[
\b[l
\bl]
\b] [-
\b-A
\bAn
\bnS
\bS] [-
\b-g
\bg _
\bg_
\br_
\bo_
\bu_
\bp_
\bn_
\ba_
\bm_
\be|_
\b#_
\bg_
\bi_
\bd] [-
\b-U
\bU _
\bu_
\bs_
\be_
\br_
\bn_
\ba_
\bm_
\be] [-
\b-u
\bu _
\bu_
\bs_
\be_
\br_
\bn_
\ba_
\bm_
\be|_
\b#_
\bu_
\bi_
\bd]
14 [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd]
16 s
\bsu
\bud
\bdo
\bo [-
\b-A
\bAb
\bbE
\bEH
\bHn
\bnP
\bPS
\bS] [-
\b-a
\ba _
\ba_
\bu_
\bt_
\bh_
\b__
\bt_
\by_
\bp_
\be] [-
\b-C
\bC _
\bf_
\bd] [-
\b-c
\bc _
\bc_
\bl_
\ba_
\bs_
\bs|_
\b-] [-
\b-g
\bg _
\bg_
\br_
\bo_
\bu_
\bp_
\bn_
\ba_
\bm_
\be|_
\b#_
\bg_
\bi_
\bd]
17 [-
\b-p
\bp _
\bp_
\br_
\bo_
\bm_
\bp_
\bt] [-
\b-u
\bu _
\bu_
\bs_
\be_
\br_
\bn_
\ba_
\bm_
\be|_
\b#_
\bu_
\bi_
\bd] [V
\bVA
\bAR
\bR=_
\bv_
\ba_
\bl_
\bu_
\be] [-
\b-i
\bi | -
\b-s
\bs] [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd]
19 s
\bsu
\bud
\bdo
\boe
\bed
\bdi
\bit
\bt [-
\b-A
\bAn
\bnS
\bS] [-
\b-a
\ba _
\ba_
\bu_
\bt_
\bh_
\b__
\bt_
\by_
\bp_
\be] [-
\b-C
\bC _
\bf_
\bd] [-
\b-c
\bc _
\bc_
\bl_
\ba_
\bs_
\bs|_
\b-] [-
\b-g
\bg _
\bg_
\br_
\bo_
\bu_
\bp_
\bn_
\ba_
\bm_
\be|_
\b#_
\bg_
\bi_
\bd]
20 [-
\b-p
\bp _
\bp_
\br_
\bo_
\bm_
\bp_
\bt] [-
\b-u
\bu _
\bu_
\bs_
\be_
\br_
\bn_
\ba_
\bm_
\be|_
\b#_
\bu_
\bi_
\bd] file ...
22 D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
23 s
\bsu
\bud
\bdo
\bo allows a permitted user to execute a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd as the superuser or
24 another user, as specified in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file. The real and effective
25 uid and gid are set to match those of the target user as specified in
26 the passwd file and the group vector is initialized based on the group
27 file (unless the -
\b-P
\bP option was specified). If the invoking user is
28 root or if the target user is the same as the invoking user, no
29 password is required. Otherwise, s
\bsu
\bud
\bdo
\bo requires that users authenticate
30 themselves with a password by default (NOTE: in the default
31 configuration this is the user's password, not the root password).
32 Once a user has been authenticated, a timestamp is updated and the user
33 may then use sudo without a password for a short period of time (5
34 minutes unless overridden in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs).
36 When invoked as s
\bsu
\bud
\bdo
\boe
\bed
\bdi
\bit
\bt, the -
\b-e
\be option (described below), is implied.
38 s
\bsu
\bud
\bdo
\bo determines who is an authorized user by consulting the file
39 _
\b/_
\be_
\bt_
\bc_
\b/_
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs. By running s
\bsu
\bud
\bdo
\bo with the -
\b-v
\bv option, a user can update
40 the time stamp without running a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd. The password prompt itself
41 will also time out if the user's password is not entered within 5
42 minutes (unless overridden via _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs).
44 If a user who is not listed in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file tries to run a command
45 via s
\bsu
\bud
\bdo
\bo, mail is sent to the proper authorities, as defined at
46 configure time or in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file (defaults to root). Note that
47 the mail will not be sent if an unauthorized user tries to run sudo
48 with the -
\b-l
\bl or -
\b-v
\bv option. This allows users to determine for
49 themselves whether or not they are allowed to use s
\bsu
\bud
\bdo
\bo.
51 If s
\bsu
\bud
\bdo
\bo is run by root and the SUDO_USER environment variable is set,
52 s
\bsu
\bud
\bdo
\bo will use this value to determine who the actual user is. This can
53 be used by a user to log commands through sudo even when a root shell
54 has been invoked. It also allows the -
\b-e
\be option to remain useful even
55 when being run via a sudo-run script or program. Note however, that
56 the sudoers lookup is still done for root, not the user specified by
59 s
\bsu
\bud
\bdo
\bo can log both successful and unsuccessful attempts (as well as
60 errors) to _
\bs_
\by_
\bs_
\bl_
\bo_
\bg(3), a log file, or both. By default s
\bsu
\bud
\bdo
\bo will log
64 1.7.0 November 15, 2008 1
70 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
73 via _
\bs_
\by_
\bs_
\bl_
\bo_
\bg(3) but this is changeable at configure time or via the
74 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file.
76 O
\bOP
\bPT
\bTI
\bIO
\bON
\bNS
\bS
77 s
\bsu
\bud
\bdo
\bo accepts the following command line options:
79 -A Normally, if s
\bsu
\bud
\bdo
\bo requires a password, it will read it from
80 the current terminal. If the -
\b-A
\bA (_
\ba_
\bs_
\bk_
\bp_
\ba_
\bs_
\bs) option is
81 specified, a helper program is executed to read the user's
82 password and output the password to the standard output.
83 If the SUDO_ASKPASS environment variable is set, it
84 specifies the path to the helper program. Otherwise, the
85 value specified by the _
\ba_
\bs_
\bk_
\bp_
\ba_
\bs_
\bs option in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) is
88 -a _
\bt_
\by_
\bp_
\be The -
\b-a
\ba (_
\ba_
\bu_
\bt_
\bh_
\be_
\bn_
\bt_
\bi_
\bc_
\ba_
\bt_
\bi_
\bo_
\bn _
\bt_
\by_
\bp_
\be) option causes s
\bsu
\bud
\bdo
\bo to use the
89 specified authentication type when validating the user, as
90 allowed by _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf. The system administrator may
91 specify a list of sudo-specific authentication methods by
92 adding an "auth-sudo" entry in _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf. This
93 option is only available on systems that support BSD
96 -b The -
\b-b
\bb (_
\bb_
\ba_
\bc_
\bk_
\bg_
\br_
\bo_
\bu_
\bn_
\bd) option tells s
\bsu
\bud
\bdo
\bo to run the given
97 command in the background. Note that if you use the -
\b-b
\bb
98 option you cannot use shell job control to manipulate the
101 -C _
\bf_
\bd Normally, s
\bsu
\bud
\bdo
\bo will close all open file descriptors other
102 than standard input, standard output and standard error.
103 The -
\b-C
\bC (_
\bc_
\bl_
\bo_
\bs_
\be _
\bf_
\br_
\bo_
\bm) option allows the user to specify a
104 starting point above the standard error (file descriptor
105 three). Values less than three are not permitted. This
106 option is only available if the administrator has enabled
107 the _
\bc_
\bl_
\bo_
\bs_
\be_
\bf_
\br_
\bo_
\bm_
\b__
\bo_
\bv_
\be_
\br_
\br_
\bi_
\bd_
\be option in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4).
109 -c _
\bc_
\bl_
\ba_
\bs_
\bs The -
\b-c
\bc (_
\bc_
\bl_
\ba_
\bs_
\bs) option causes s
\bsu
\bud
\bdo
\bo to run the specified
110 command with resources limited by the specified login
111 class. The _
\bc_
\bl_
\ba_
\bs_
\bs argument can be either a class name as
112 defined in _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf, or a single '-' character.
113 Specifying a _
\bc_
\bl_
\ba_
\bs_
\bs of - indicates that the command should
114 be run restricted by the default login capabilities for the
115 user the command is run as. If the _
\bc_
\bl_
\ba_
\bs_
\bs argument
116 specifies an existing user class, the command must be run
117 as root, or the s
\bsu
\bud
\bdo
\bo command must be run from a shell that
118 is already root. This option is only available on systems
119 with BSD login classes.
121 -E The -
\b-E
\bE (_
\bp_
\br_
\be_
\bs_
\be_
\br_
\bv_
\be _
\be_
\bn_
\bv_
\bi_
\br_
\bo_
\bn_
\bm_
\be_
\bn_
\bt) option will override the
122 _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt option in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4)). It is only available when
123 either the matching command has the SETENV tag or the
124 _
\bs_
\be_
\bt_
\be_
\bn_
\bv option is set in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4).
126 -e The -
\b-e
\be (_
\be_
\bd_
\bi_
\bt) option indicates that, instead of running a
130 1.7.0 November 15, 2008 2
136 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
139 command, the user wishes to edit one or more files. In
140 lieu of a command, the string "sudoedit" is used when
141 consulting the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file. If the user is authorized by
142 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs the following steps are taken:
144 1. Temporary copies are made of the files to be edited
145 with the owner set to the invoking user.
147 2. The editor specified by the SUDO_EDITOR, VISUAL or
148 EDITOR environment variables is run to edit the
149 temporary files. If none of SUDO_EDITOR, VISUAL or
150 EDITOR are set, the first program listed in the _
\be_
\bd_
\bi_
\bt_
\bo_
\br
151 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs variable is used.
153 3. If they have been modified, the temporary files are
154 copied back to their original location and the
155 temporary versions are removed.
157 If the specified file does not exist, it will be created.
158 Note that unlike most commands run by s
\bsu
\bud
\bdo
\bo, the editor is
159 run with the invoking user's environment unmodified. If,
160 for some reason, s
\bsu
\bud
\bdo
\bo is unable to update a file with its
161 edited version, the user will receive a warning and the
162 edited copy will remain in a temporary file.
164 -g _
\bg_
\br_
\bo_
\bu_
\bp Normally, s
\bsu
\bud
\bdo
\bo sets the primary group to the one specified
165 by the passwd database for the user the command is being
166 run as (by default, root). The -
\b-g
\bg (_
\bg_
\br_
\bo_
\bu_
\bp) option causes
167 s
\bsu
\bud
\bdo
\bo to run the specified command with the primary group
168 set to _
\bg_
\br_
\bo_
\bu_
\bp. To specify a _
\bg_
\bi_
\bd instead of a _
\bg_
\br_
\bo_
\bu_
\bp _
\bn_
\ba_
\bm_
\be,
169 use _
\b#_
\bg_
\bi_
\bd. When running commands as a _
\bg_
\bi_
\bd, many shells
170 require that the '#' be escaped with a backslash ('\'). If
171 no -
\b-u
\bu option is specified, the command will be run as the
172 invoking user (not root). In either case, the primary
173 group will be set to _
\bg_
\br_
\bo_
\bu_
\bp.
175 -H The -
\b-H
\bH (_
\bH_
\bO_
\bM_
\bE) option sets the HOME environment variable to
176 the homedir of the target user (root by default) as
177 specified in _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4). By default, s
\bsu
\bud
\bdo
\bo does not modify
178 HOME (see _
\bs_
\be_
\bt_
\b__
\bh_
\bo_
\bm_
\be and _
\ba_
\bl_
\bw_
\ba_
\by_
\bs_
\b__
\bs_
\be_
\bt_
\b__
\bh_
\bo_
\bm_
\be in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4)).
180 -h The -
\b-h
\bh (_
\bh_
\be_
\bl_
\bp) option causes s
\bsu
\bud
\bdo
\bo to print a usage message
184 The -
\b-i
\bi (_
\bs_
\bi_
\bm_
\bu_
\bl_
\ba_
\bt_
\be _
\bi_
\bn_
\bi_
\bt_
\bi_
\ba_
\bl _
\bl_
\bo_
\bg_
\bi_
\bn) option runs the shell
185 specified in the _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4) entry of the target user as a
186 login shell. This means that login-specific resource files
187 such as .profile or .login will be read by the shell. If a
188 command is specified, it is passed to the shell for
189 execution. Otherwise, an interactive shell is executed.
190 s
\bsu
\bud
\bdo
\bo attempts to change to that user's home directory
191 before running the shell. It also initializes the
192 environment, leaving _
\bD_
\bI_
\bS_
\bP_
\bL_
\bA_
\bY and _
\bT_
\bE_
\bR_
\bM unchanged, setting
196 1.7.0 November 15, 2008 3
202 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
205 _
\bH_
\bO_
\bM_
\bE, _
\bS_
\bH_
\bE_
\bL_
\bL, _
\bU_
\bS_
\bE_
\bR, _
\bL_
\bO_
\bG_
\bN_
\bA_
\bM_
\bE, and _
\bP_
\bA_
\bT_
\bH, as well as the
206 contents of _
\b/_
\be_
\bt_
\bc_
\b/_
\be_
\bn_
\bv_
\bi_
\br_
\bo_
\bn_
\bm_
\be_
\bn_
\bt on Linux and AIX systems. All
207 other environment variables are removed.
209 -K The -
\b-K
\bK (sure _
\bk_
\bi_
\bl_
\bl) option is like -
\b-k
\bk except that it removes
210 the user's timestamp entirely. Like -
\b-k
\bk, this option does
211 not require a password.
213 -k The -
\b-k
\bk (_
\bk_
\bi_
\bl_
\bl) option to s
\bsu
\bud
\bdo
\bo invalidates the user's
214 timestamp by setting the time on it to the Epoch. The next
215 time s
\bsu
\bud
\bdo
\bo is run a password will be required. This option
216 does not require a password and was added to allow a user
217 to revoke s
\bsu
\bud
\bdo
\bo permissions from a .logout file.
219 -L The -
\b-L
\bL (_
\bl_
\bi_
\bs_
\bt defaults) option will list out the parameters
220 that may be set in a _
\bD_
\be_
\bf_
\ba_
\bu_
\bl_
\bt_
\bs line along with a short
221 description for each. This option is useful in conjunction
222 with _
\bg_
\br_
\be_
\bp(1).
224 -l[l] [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd]
225 If no _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified, the -
\b-l
\bl (_
\bl_
\bi_
\bs_
\bt) option will list
226 the allowed (and forbidden) commands for the invoking user
227 (or the user specified by the -
\b-U
\bU option) on the current
228 host. If a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified and is permitted by
229 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs, the fully-qualified path to the command is
230 displayed along with any command line arguments. If
231 _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified but not allowed, s
\bsu
\bud
\bdo
\bo will exit with a
232 status value of 1. If the -
\b-l
\bl option is specified with an l
\bl
233 argument (i.e. -
\b-l
\bll
\bl), or if -
\b-l
\bl is specified multiple times,
234 a longer list format is used.
236 -n The -
\b-n
\bn (_
\bn_
\bo_
\bn_
\b-_
\bi_
\bn_
\bt_
\be_
\br_
\ba_
\bc_
\bt_
\bi_
\bv_
\be) option prevents s
\bsu
\bud
\bdo
\bo from
237 prompting the user for a password. If a password is
238 required for the command to run, s
\bsu
\bud
\bdo
\bo will display an error
241 -P The -
\b-P
\bP (_
\bp_
\br_
\be_
\bs_
\be_
\br_
\bv_
\be _
\bg_
\br_
\bo_
\bu_
\bp _
\bv_
\be_
\bc_
\bt_
\bo_
\br) option causes s
\bsu
\bud
\bdo
\bo to
242 preserve the invoking user's group vector unaltered. By
243 default, s
\bsu
\bud
\bdo
\bo will initialize the group vector to the list
244 of groups the target user is in. The real and effective
245 group IDs, however, are still set to match the target user.
247 -p _
\bp_
\br_
\bo_
\bm_
\bp_
\bt The -
\b-p
\bp (_
\bp_
\br_
\bo_
\bm_
\bp_
\bt) option allows you to override the default
248 password prompt and use a custom one. The following
249 percent (`%') escapes are supported:
251 %H expanded to the local hostname including the domain
252 name (on if the machine's hostname is fully qualified
253 or the _
\bf_
\bq_
\bd_
\bn _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs option is set)
255 %h expanded to the local hostname without the domain name
257 %p expanded to the user whose password is being asked for
258 (respects the _
\br_
\bo_
\bo_
\bt_
\bp_
\bw, _
\bt_
\ba_
\br_
\bg_
\be_
\bt_
\bp_
\bw and _
\br_
\bu_
\bn_
\ba_
\bs_
\bp_
\bw flags in
262 1.7.0 November 15, 2008 4
268 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
271 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs)
273 %U expanded to the login name of the user the command will
274 be run as (defaults to root)
276 %u expanded to the invoking user's login name
278 %% two consecutive % characters are collapsed into a
281 The prompt specified by the -
\b-p
\bp option will override the
282 system password prompt on systems that support PAM unless
283 the _
\bp_
\ba_
\bs_
\bs_
\bp_
\br_
\bo_
\bm_
\bp_
\bt_
\b__
\bo_
\bv_
\be_
\br_
\br_
\bi_
\bd_
\be flag is disabled in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs.
285 -S The -
\b-S
\bS (_
\bs_
\bt_
\bd_
\bi_
\bn) option causes s
\bsu
\bud
\bdo
\bo to read the password from
286 the standard input instead of the terminal device.
289 The -
\b-s
\bs (_
\bs_
\bh_
\be_
\bl_
\bl) option runs the shell specified by the _
\bS_
\bH_
\bE_
\bL_
\bL
290 environment variable if it is set or the shell as specified
291 in _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4). If a command is specified, it is passed to
292 the shell for execution. Otherwise, an interactive shell
295 -U _
\bu_
\bs_
\be_
\br The -
\b-U
\bU (_
\bo_
\bt_
\bh_
\be_
\br _
\bu_
\bs_
\be_
\br) option is used in conjunction with the
296 -
\b-l
\bl option to specify the user whose privileges should be
297 listed. Only root or a user with s
\bsu
\bud
\bdo
\bo ALL on the current
298 host may use this option.
300 -u _
\bu_
\bs_
\be_
\br The -
\b-u
\bu (_
\bu_
\bs_
\be_
\br) option causes s
\bsu
\bud
\bdo
\bo to run the specified
301 command as a user other than _
\br_
\bo_
\bo_
\bt. To specify a _
\bu_
\bi_
\bd
302 instead of a _
\bu_
\bs_
\be_
\br _
\bn_
\ba_
\bm_
\be, use _
\b#_
\bu_
\bi_
\bd. When running commands as
303 a _
\bu_
\bi_
\bd, many shells require that the '#' be escaped with a
304 backslash ('\'). Note that if the _
\bt_
\ba_
\br_
\bg_
\be_
\bt_
\bp_
\bw Defaults option
305 is set (see _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4)) it is not possible to run commands
306 with a uid not listed in the password database.
308 -V The -
\b-V
\bV (_
\bv_
\be_
\br_
\bs_
\bi_
\bo_
\bn) option causes s
\bsu
\bud
\bdo
\bo to print the version
309 number and exit. If the invoking user is already root the
310 -
\b-V
\bV option will print out a list of the defaults s
\bsu
\bud
\bdo
\bo was
311 compiled with as well as the machine's local network
314 -v If given the -
\b-v
\bv (_
\bv_
\ba_
\bl_
\bi_
\bd_
\ba_
\bt_
\be) option, s
\bsu
\bud
\bdo
\bo will update the
315 user's timestamp, prompting for the user's password if
316 necessary. This extends the s
\bsu
\bud
\bdo
\bo timeout for another 5
317 minutes (or whatever the timeout is set to in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs) but
318 does not run a command.
320 -- The -
\b--
\b- option indicates that s
\bsu
\bud
\bdo
\bo should stop processing
321 command line arguments. It is most useful in conjunction
322 with the -
\b-s
\bs option.
324 Environment variables to be set for the command may also be passed on
328 1.7.0 November 15, 2008 5
334 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
337 the command line in the form of V
\bVA
\bAR
\bR=_
\bv_
\ba_
\bl_
\bu_
\be, e.g.
338 L
\bLD
\bD_
\b_L
\bLI
\bIB
\bBR
\bRA
\bAR
\bRY
\bY_
\b_P
\bPA
\bAT
\bTH
\bH=_
\b/_
\bu_
\bs_
\br_
\b/_
\bl_
\bo_
\bc_
\ba_
\bl_
\b/_
\bp_
\bk_
\bg_
\b/_
\bl_
\bi_
\bb. Variables passed on the command
339 line are subject to the same restrictions as normal environment
340 variables with one important exception. If the _
\bs_
\be_
\bt_
\be_
\bn_
\bv option is set in
341 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs, the command to be run has the SETENV tag set or the command
342 matched is ALL, the user may set variables that would overwise be
343 forbidden. See _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) for more information.
345 R
\bRE
\bET
\bTU
\bUR
\bRN
\bN V
\bVA
\bAL
\bLU
\bUE
\bES
\bS
346 Upon successful execution of a program, the exit status from s
\bsu
\bud
\bdo
\bo will
347 simply be the exit status of the program that was executed.
349 Otherwise, s
\bsu
\bud
\bdo
\bo quits with an exit value of 1 if there is a
350 configuration/permission problem or if s
\bsu
\bud
\bdo
\bo cannot execute the given
351 command. In the latter case the error string is printed to stderr. If
352 s
\bsu
\bud
\bdo
\bo cannot _
\bs_
\bt_
\ba_
\bt(2) one or more entries in the user's PATH an error is
353 printed on stderr. (If the directory does not exist or if it is not
354 really a directory, the entry is ignored and no error is printed.)
355 This should not happen under normal circumstances. The most common
356 reason for _
\bs_
\bt_
\ba_
\bt(2) to return "permission denied" is if you are running
357 an automounter and one of the directories in your PATH is on a machine
358 that is currently unreachable.
360 S
\bSE
\bEC
\bCU
\bUR
\bRI
\bIT
\bTY
\bY N
\bNO
\bOT
\bTE
\bES
\bS
361 s
\bsu
\bud
\bdo
\bo tries to be safe when executing external commands.
363 There are two distinct ways to deal with environment variables. By
364 default, the _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs option is enabled. This causes commands
365 to be executed with a minimal environment containing TERM, PATH, HOME,
366 SHELL, LOGNAME, USER and USERNAME in addition to variables from the
367 invoking process permitted by the _
\be_
\bn_
\bv_
\b__
\bc_
\bh_
\be_
\bc_
\bk and _
\be_
\bn_
\bv_
\b__
\bk_
\be_
\be_
\bp _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs
368 options. There is effectively a whitelist for environment variables.
370 If, however, the _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt option is disabled in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs, any variables
371 not explicitly denied by the _
\be_
\bn_
\bv_
\b__
\bc_
\bh_
\be_
\bc_
\bk and _
\be_
\bn_
\bv_
\b__
\bd_
\be_
\bl_
\be_
\bt_
\be options are
372 inherited from the invoking process. In this case, _
\be_
\bn_
\bv_
\b__
\bc_
\bh_
\be_
\bc_
\bk and
373 _
\be_
\bn_
\bv_
\b__
\bd_
\be_
\bl_
\be_
\bt_
\be behave like a blacklist. Since it is not possible to
374 blacklist all potentially dangerous environment variables, use of the
375 default _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt behavior is encouraged.
377 In all cases, environment variables with a value beginning with () are
378 removed as they could be interpreted as b
\bba
\bas
\bsh
\bh functions. The list of
379 environment variables that s
\bsu
\bud
\bdo
\bo allows or denies is contained in the
380 output of sudo -V when run as root.
382 Note that the dynamic linker on most operating systems will remove
383 variables that can control dynamic linking from the environment of
384 setuid executables, including s
\bsu
\bud
\bdo
\bo. Depending on the operating system
385 this may include _RLD*, DYLD_*, LD_*, LDR_*, LIBPATH, SHLIB_PATH, and
386 others. These type of variables are removed from the environment
387 before s
\bsu
\bud
\bdo
\bo even begins execution and, as such, it is not possible for
388 s
\bsu
\bud
\bdo
\bo to preserve them.
390 To prevent command spoofing, s
\bsu
\bud
\bdo
\bo checks "." and "" (both denoting
394 1.7.0 November 15, 2008 6
400 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
403 current directory) last when searching for a command in the user's PATH
404 (if one or both are in the PATH). Note, however, that the actual PATH
405 environment variable is _
\bn_
\bo_
\bt modified and is passed unchanged to the
406 program that s
\bsu
\bud
\bdo
\bo executes.
408 s
\bsu
\bud
\bdo
\bo will check the ownership of its timestamp directory (_
\b/_
\bv_
\ba_
\br_
\b/_
\br_
\bu_
\bn_
\b/_
\bs_
\bu_
\bd_
\bo
409 by default) and ignore the directory's contents if it is not owned by
410 root or if it is writable by a user other than root. On systems that
411 allow non-root users to give away files via _
\bc_
\bh_
\bo_
\bw_
\bn(2), if the timestamp
412 directory is located in a directory writable by anyone (e.g., _
\b/_
\bt_
\bm_
\bp), it
413 is possible for a user to create the timestamp directory before s
\bsu
\bud
\bdo
\bo is
414 run. However, because s
\bsu
\bud
\bdo
\bo checks the ownership and mode of the
415 directory and its contents, the only damage that can be done is to
416 "hide" files by putting them in the timestamp dir. This is unlikely to
417 happen since once the timestamp dir is owned by root and inaccessible
418 by any other user, the user placing files there would be unable to get
419 them back out. To get around this issue you can use a directory that
420 is not world-writable for the timestamps (_
\b/_
\bv_
\ba_
\br_
\b/_
\ba_
\bd_
\bm_
\b/_
\bs_
\bu_
\bd_
\bo for instance)
421 or create _
\b/_
\bv_
\ba_
\br_
\b/_
\br_
\bu_
\bn_
\b/_
\bs_
\bu_
\bd_
\bo with the appropriate owner (root) and
422 permissions (0700) in the system startup files.
424 s
\bsu
\bud
\bdo
\bo will not honor timestamps set far in the future. Timestamps with
425 a date greater than current_time + 2 * TIMEOUT will be ignored and sudo
426 will log and complain. This is done to keep a user from creating
427 his/her own timestamp with a bogus date on systems that allow users to
430 Please note that s
\bsu
\bud
\bdo
\bo will normally only log the command it explicitly
431 runs. If a user runs a command such as sudo su or sudo sh, subsequent
432 commands run from that shell will _
\bn_
\bo_
\bt be logged, nor will s
\bsu
\bud
\bdo
\bo's access
433 control affect them. The same is true for commands that offer shell
434 escapes (including most editors). Because of this, care must be taken
435 when giving users access to commands via s
\bsu
\bud
\bdo
\bo to verify that the
436 command does not inadvertently give the user an effective root shell.
437 For more information, please see the PREVENTING SHELL ESCAPES section
438 in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4).
440 E
\bEN
\bNV
\bVI
\bIR
\bRO
\bON
\bNM
\bME
\bEN
\bNT
\bT
441 s
\bsu
\bud
\bdo
\bo utilizes the following environment variables:
443 EDITOR Default editor to use in -
\b-e
\be (sudoedit) mode if neither
444 SUDO_EDITOR nor VISUAL is set
446 HOME In -
\b-s
\bs or -
\b-H
\bH mode (or if sudo was configured with the
447 --enable-shell-sets-home option), set to homedir of the
450 PATH Set to a sane value if the _
\bs_
\be_
\bc_
\bu_
\br_
\be_
\b__
\bp_
\ba_
\bt_
\bh sudoers option
453 SHELL Used to determine shell to run with -s option
455 SUDO_ASKPASS Specifies the path to a helper program used to read the
456 password if no terminal is available or if the -A
460 1.7.0 November 15, 2008 7
466 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
471 SUDO_COMMAND Set to the command run by sudo
473 SUDO_EDITOR Default editor to use in -
\b-e
\be (sudoedit) mode
475 SUDO_GID Set to the group ID of the user who invoked sudo
477 SUDO_PROMPT Used as the default password prompt
479 SUDO_PS1 If set, PS1 will be set to its value for the program
482 SUDO_UID Set to the user ID of the user who invoked sudo
484 SUDO_USER Set to the login of the user who invoked sudo
486 USER Set to the target user (root unless the -
\b-u
\bu option is
489 VISUAL Default editor to use in -
\b-e
\be (sudoedit) mode if
490 SUDO_EDITOR is not set
493 _
\b/_
\be_
\bt_
\bc_
\b/_
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs List of who can run what
495 _
\b/_
\bv_
\ba_
\br_
\b/_
\br_
\bu_
\bn_
\b/_
\bs_
\bu_
\bd_
\bo Directory containing timestamps
497 _
\b/_
\be_
\bt_
\bc_
\b/_
\be_
\bn_
\bv_
\bi_
\br_
\bo_
\bn_
\bm_
\be_
\bn_
\bt Initial environment for -
\b-i
\bi mode on Linux and
500 E
\bEX
\bXA
\bAM
\bMP
\bPL
\bLE
\bES
\bS
501 Note: the following examples assume suitable _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) entries.
503 To get a file listing of an unreadable directory:
505 $ sudo ls /usr/local/protected
507 To list the home directory of user yazza on a machine where the file
508 system holding ~yazza is not exported as root:
510 $ sudo -u yazza ls ~yazza
512 To edit the _
\bi_
\bn_
\bd_
\be_
\bx_
\b._
\bh_
\bt_
\bm_
\bl file as user www:
514 $ sudo -u www vi ~www/htdocs/index.html
516 To shutdown a machine:
518 $ sudo shutdown -r +15 "quick reboot"
520 To make a usage listing of the directories in the /home partition.
521 Note that this runs the commands in a sub-shell to make the cd and file
526 1.7.0 November 15, 2008 8
532 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
535 $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
537 S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
538 _
\bg_
\br_
\be_
\bp(1), _
\bs_
\bu(1), _
\bs_
\bt_
\ba_
\bt(2), _
\bl_
\bo_
\bg_
\bi_
\bn_
\b__
\bc_
\ba_
\bp(3), _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4), _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(5),
539 _
\bv_
\bi_
\bs_
\bu_
\bd_
\bo(1m)
541 A
\bAU
\bUT
\bTH
\bHO
\bOR
\bRS
\bS
542 Many people have worked on s
\bsu
\bud
\bdo
\bo over the years; this version consists
543 of code written primarily by:
547 See the HISTORY file in the s
\bsu
\bud
\bdo
\bo distribution or visit
548 http://www.sudo.ws/sudo/history.html for a short history of s
\bsu
\bud
\bdo
\bo.
550 C
\bCA
\bAV
\bVE
\bEA
\bAT
\bTS
\bS
551 There is no easy way to prevent a user from gaining a root shell if
552 that user is allowed to run arbitrary commands via s
\bsu
\bud
\bdo
\bo. Also, many
553 programs (such as editors) allow the user to run commands via shell
554 escapes, thus avoiding s
\bsu
\bud
\bdo
\bo's checks. However, on most systems it is
555 possible to prevent shell escapes with s
\bsu
\bud
\bdo
\bo's _
\bn_
\bo_
\be_
\bx_
\be_
\bc functionality.
556 See the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) manual for details.
558 It is not meaningful to run the cd command directly via sudo, e.g.,
560 $ sudo cd /usr/local/protected
562 since when the command exits the parent process (your shell) will still
563 be the same. Please see the EXAMPLES section for more information.
565 If users have sudo ALL there is nothing to prevent them from creating
566 their own program that gives them a root shell regardless of any '!'
567 elements in the user specification.
569 Running shell scripts via s
\bsu
\bud
\bdo
\bo can expose the same kernel bugs that
570 make setuid shell scripts unsafe on some operating systems (if your OS
571 has a /dev/fd/ directory, setuid shell scripts are generally safe).
574 If you feel you have found a bug in s
\bsu
\bud
\bdo
\bo, please submit a bug report at
575 http://www.sudo.ws/sudo/bugs/
577 S
\bSU
\bUP
\bPP
\bPO
\bOR
\bRT
\bT
578 Limited free support is available via the sudo-users mailing list, see
579 http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
582 D
\bDI
\bIS
\bSC
\bCL
\bLA
\bAI
\bIM
\bME
\bER
\bR
583 s
\bsu
\bud
\bdo
\bo is provided ``AS IS'' and any express or implied warranties,
584 including, but not limited to, the implied warranties of
585 merchantability and fitness for a particular purpose are disclaimed.
586 See the LICENSE file distributed with s
\bsu
\bud
\bdo
\bo or
587 http://www.sudo.ws/sudo/license.html for complete details.
592 1.7.0 November 15, 2008 9