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-h
\bh | -
\b-K
\bK | -
\b-k
\bk | -
\b-L
\bL | -
\b-V
\bV
13 s
\bsu
\bud
\bdo
\bo -
\b-v
\bv [-
\b-A
\bAk
\bkn
\bnS
\bS] [-
\b-a
\ba _
\ba_
\bu_
\bt_
\bh_
\b__
\bt_
\by_
\bp_
\be] [-
\b-p
\bp _
\bp_
\br_
\bo_
\bm_
\bp_
\bt]
15 s
\bsu
\bud
\bdo
\bo -
\b-l
\bl[
\b[l
\bl]
\b] [-
\b-A
\bAk
\bkn
\bnS
\bS] [-
\b-a
\ba _
\ba_
\bu_
\bt_
\bh_
\b__
\bt_
\by_
\bp_
\be] [-
\b-g
\bg _
\bg_
\br_
\bo_
\bu_
\bp_
\bn_
\ba_
\bm_
\be|_
\b#_
\bg_
\bi_
\bd] [-
\b-p
\bp _
\bp_
\br_
\bo_
\bm_
\bp_
\bt]
16 [-
\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] [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd]
18 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]
19 [-
\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]
21 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]
22 [-
\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 ...
24 D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
25 s
\bsu
\bud
\bdo
\bo allows a permitted user to execute a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd as the superuser or
26 another user, as specified in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file. The real and effective
27 uid and gid are set to match those of the target user as specified in
28 the passwd file and the group vector is initialized based on the group
29 file (unless the -
\b-P
\bP option was specified). If the invoking user is
30 root or if the target user is the same as the invoking user, no
31 password is required. Otherwise, s
\bsu
\bud
\bdo
\bo requires that users authenticate
32 themselves with a password by default (NOTE: in the default
33 configuration this is the user's password, not the root password).
34 Once a user has been authenticated, a timestamp is updated and the user
35 may then use sudo without a password for a short period of time (5
36 minutes unless overridden in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs).
38 When invoked as s
\bsu
\bud
\bdo
\boe
\bed
\bdi
\bit
\bt, the -
\b-e
\be option (described below), is implied.
40 s
\bsu
\bud
\bdo
\bo determines who is an authorized user by consulting the file
41 _
\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
42 the time stamp without running a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd. The password prompt itself
43 will also time out if the user's password is not entered within 5
44 minutes (unless overridden via _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs).
46 If a user who is not listed in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file tries to run a command
47 via s
\bsu
\bud
\bdo
\bo, mail is sent to the proper authorities, as defined at
48 configure time or in the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file (defaults to root). Note that
49 the mail will not be sent if an unauthorized user tries to run sudo
50 with the -
\b-l
\bl or -
\b-v
\bv option. This allows users to determine for
51 themselves whether or not they are allowed to use s
\bsu
\bud
\bdo
\bo.
53 If s
\bsu
\bud
\bdo
\bo is run by root and the SUDO_USER environment variable is set,
54 s
\bsu
\bud
\bdo
\bo will use this value to determine who the actual user is. This can
55 be used by a user to log commands through sudo even when a root shell
56 has been invoked. It also allows the -
\b-e
\be option to remain useful even
57 when being run via a sudo-run script or program. Note however, that
58 the sudoers lookup is still done for root, not the user specified by
70 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
73 s
\bsu
\bud
\bdo
\bo can log both successful and unsuccessful attempts (as well as
74 errors) to _
\bs_
\by_
\bs_
\bl_
\bo_
\bg(3), a log file, or both. By default s
\bsu
\bud
\bdo
\bo will log
75 via _
\bs_
\by_
\bs_
\bl_
\bo_
\bg(3) but this is changeable at configure time or via the
76 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file.
78 O
\bOP
\bPT
\bTI
\bIO
\bON
\bNS
\bS
79 s
\bsu
\bud
\bdo
\bo accepts the following command line options:
81 -A Normally, if s
\bsu
\bud
\bdo
\bo requires a password, it will read it from
82 the current terminal. If the -
\b-A
\bA (_
\ba_
\bs_
\bk_
\bp_
\ba_
\bs_
\bs) option is
83 specified, a (possibly graphical) helper program is
84 executed to read the user's password and output the
85 password to the standard output. If the SUDO_ASKPASS
86 environment variable is set, it specifies the path to the
87 helper program. Otherwise, the value specified by the
88 _
\ba_
\bs_
\bk_
\bp_
\ba_
\bs_
\bs option in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) is used.
90 -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
91 specified authentication type when validating the user, as
92 allowed by _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf. The system administrator may
93 specify a list of sudo-specific authentication methods by
94 adding an "auth-sudo" entry in _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf. This
95 option is only available on systems that support BSD
98 -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
99 command in the background. Note that if you use the -
\b-b
\bb
100 option you cannot use shell job control to manipulate the
103 -C _
\bf_
\bd Normally, s
\bsu
\bud
\bdo
\bo will close all open file descriptors other
104 than standard input, standard output and standard error.
105 The -
\b-C
\bC (_
\bc_
\bl_
\bo_
\bs_
\be _
\bf_
\br_
\bo_
\bm) option allows the user to specify a
106 starting point above the standard error (file descriptor
107 three). Values less than three are not permitted. This
108 option is only available if the administrator has enabled
109 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).
111 -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
112 command with resources limited by the specified login
113 class. The _
\bc_
\bl_
\ba_
\bs_
\bs argument can be either a class name as
114 defined in _
\b/_
\be_
\bt_
\bc_
\b/_
\bl_
\bo_
\bg_
\bi_
\bn_
\b._
\bc_
\bo_
\bn_
\bf, or a single '-' character.
115 Specifying a _
\bc_
\bl_
\ba_
\bs_
\bs of - indicates that the command should
116 be run restricted by the default login capabilities for the
117 user the command is run as. If the _
\bc_
\bl_
\ba_
\bs_
\bs argument
118 specifies an existing user class, the command must be run
119 as root, or the s
\bsu
\bud
\bdo
\bo command must be run from a shell that
120 is already root. This option is only available on systems
121 with BSD login classes.
123 -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
124 _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt option in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4)). It is only available when
125 either the matching command has the SETENV tag or the
126 _
\bs_
\be_
\bt_
\be_
\bn_
\bv option is set in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4).
130 1.7.2 June 15, 2009 2
136 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
139 -e The -
\b-e
\be (_
\be_
\bd_
\bi_
\bt) option indicates that, instead of running a
140 command, the user wishes to edit one or more files. In
141 lieu of a command, the string "sudoedit" is used when
142 consulting the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs file. If the user is authorized by
143 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs the following steps are taken:
145 1. Temporary copies are made of the files to be edited
146 with the owner set to the invoking user.
148 2. The editor specified by the SUDO_EDITOR, VISUAL or
149 EDITOR environment variables is run to edit the
150 temporary files. If none of SUDO_EDITOR, VISUAL or
151 EDITOR are set, the first program listed in the _
\be_
\bd_
\bi_
\bt_
\bo_
\br
152 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs variable is used.
154 3. If they have been modified, the temporary files are
155 copied back to their original location and the
156 temporary versions are removed.
158 If the specified file does not exist, it will be created.
159 Note that unlike most commands run by s
\bsu
\bud
\bdo
\bo, the editor is
160 run with the invoking user's environment unmodified. If,
161 for some reason, s
\bsu
\bud
\bdo
\bo is unable to update a file with its
162 edited version, the user will receive a warning and the
163 edited copy will remain in a temporary file.
165 -g _
\bg_
\br_
\bo_
\bu_
\bp Normally, s
\bsu
\bud
\bdo
\bo sets the primary group to the one specified
166 by the passwd database for the user the command is being
167 run as (by default, root). The -
\b-g
\bg (_
\bg_
\br_
\bo_
\bu_
\bp) option causes
168 s
\bsu
\bud
\bdo
\bo to run the specified command with the primary group
169 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,
170 use _
\b#_
\bg_
\bi_
\bd. When running commands as a _
\bg_
\bi_
\bd, many shells
171 require that the '#' be escaped with a backslash ('\'). If
172 no -
\b-u
\bu option is specified, the command will be run as the
173 invoking user (not root). In either case, the primary
174 group will be set to _
\bg_
\br_
\bo_
\bu_
\bp.
176 -H The -
\b-H
\bH (_
\bH_
\bO_
\bM_
\bE) option sets the HOME environment variable to
177 the homedir of the target user (root by default) as
178 specified in _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4). By default, s
\bsu
\bud
\bdo
\bo does not modify
179 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)).
181 -h The -
\b-h
\bh (_
\bh_
\be_
\bl_
\bp) option causes s
\bsu
\bud
\bdo
\bo to print a usage message
185 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
186 specified in the _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4) entry of the target user as a
187 login shell. This means that login-specific resource files
188 such as .profile or .login will be read by the shell. If a
189 command is specified, it is passed to the shell for
190 execution. Otherwise, an interactive shell is executed.
191 s
\bsu
\bud
\bdo
\bo attempts to change to that user's home directory
192 before running the shell. It also initializes the
196 1.7.2 June 15, 2009 3
202 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
205 environment, leaving _
\bD_
\bI_
\bS_
\bP_
\bL_
\bA_
\bY and _
\bT_
\bE_
\bR_
\bM unchanged, setting
206 _
\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
207 contents of _
\b/_
\be_
\bt_
\bc_
\b/_
\be_
\bn_
\bv_
\bi_
\br_
\bo_
\bn_
\bm_
\be_
\bn_
\bt on Linux and AIX systems. All
208 other environment variables are removed.
210 -K The -
\b-K
\bK (sure _
\bk_
\bi_
\bl_
\bl) option is like -
\b-k
\bk except that it removes
211 the user's timestamp entirely and may not be used in
212 conjunction with a command or other option. This option
213 does not require a password.
215 -k When used by itself, the -
\b-k
\bk (_
\bk_
\bi_
\bl_
\bl) option to s
\bsu
\bud
\bdo
\bo
216 invalidates the user's timestamp by setting the time on it
217 to the Epoch. The next time s
\bsu
\bud
\bdo
\bo is run a password will be
218 required. This option does not require a password and was
219 added to allow a user to revoke s
\bsu
\bud
\bdo
\bo permissions from a
222 When used in conjunction with a command or an option that
223 may require a password, the -
\b-k
\bk option will cause s
\bsu
\bud
\bdo
\bo to
224 ignore the user's timestamp file. As a result, s
\bsu
\bud
\bdo
\bo will
225 prompt for a password (if one is required by _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs) and
226 will not update the user's timestamp file.
228 -L The -
\b-L
\bL (_
\bl_
\bi_
\bs_
\bt defaults) option will list out the parameters
229 that may be set in a _
\bD_
\be_
\bf_
\ba_
\bu_
\bl_
\bt_
\bs line along with a short
230 description for each. This option is useful in conjunction
231 with _
\bg_
\br_
\be_
\bp(1).
233 -l[l] [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd]
234 If no _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified, the -
\b-l
\bl (_
\bl_
\bi_
\bs_
\bt) option will list
235 the allowed (and forbidden) commands for the invoking user
236 (or the user specified by the -
\b-U
\bU option) on the current
237 host. If a _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified and is permitted by
238 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs, the fully-qualified path to the command is
239 displayed along with any command line arguments. If
240 _
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd is specified but not allowed, s
\bsu
\bud
\bdo
\bo will exit with a
241 status value of 1. If the -
\b-l
\bl option is specified with an l
\bl
242 argument (i.e. -
\b-l
\bll
\bl), or if -
\b-l
\bl is specified multiple times,
243 a longer list format is used.
245 -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
246 prompting the user for a password. If a password is
247 required for the command to run, s
\bsu
\bud
\bdo
\bo will display an error
250 -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
251 preserve the invoking user's group vector unaltered. By
252 default, s
\bsu
\bud
\bdo
\bo will initialize the group vector to the list
253 of groups the target user is in. The real and effective
254 group IDs, however, are still set to match the target user.
256 -p _
\bp_
\br_
\bo_
\bm_
\bp_
\bt The -
\b-p
\bp (_
\bp_
\br_
\bo_
\bm_
\bp_
\bt) option allows you to override the default
257 password prompt and use a custom one. The following
258 percent (`%') escapes are supported:
262 1.7.2 June 15, 2009 4
268 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
271 %H expanded to the local hostname including the domain
272 name (on if the machine's hostname is fully qualified
273 or the _
\bf_
\bq_
\bd_
\bn _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs option is set)
275 %h expanded to the local hostname without the domain name
277 %p expanded to the user whose password is being asked for
278 (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
279 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs)
281 %U expanded to the login name of the user the command will
282 be run as (defaults to root)
284 %u expanded to the invoking user's login name
286 %% two consecutive % characters are collapsed into a
289 The prompt specified by the -
\b-p
\bp option will override the
290 system password prompt on systems that support PAM unless
291 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.
293 -S The -
\b-S
\bS (_
\bs_
\bt_
\bd_
\bi_
\bn) option causes s
\bsu
\bud
\bdo
\bo to read the password from
294 the standard input instead of the terminal device.
297 The -
\b-s
\bs (_
\bs_
\bh_
\be_
\bl_
\bl) option runs the shell specified by the _
\bS_
\bH_
\bE_
\bL_
\bL
298 environment variable if it is set or the shell as specified
299 in _
\bp_
\ba_
\bs_
\bs_
\bw_
\bd(4). If a command is specified, it is passed to
300 the shell for execution. Otherwise, an interactive shell
303 -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
304 -
\b-l
\bl option to specify the user whose privileges should be
305 listed. Only root or a user with s
\bsu
\bud
\bdo
\bo ALL on the current
306 host may use this option.
308 -u _
\bu_
\bs_
\be_
\br The -
\b-u
\bu (_
\bu_
\bs_
\be_
\br) option causes s
\bsu
\bud
\bdo
\bo to run the specified
309 command as a user other than _
\br_
\bo_
\bo_
\bt. To specify a _
\bu_
\bi_
\bd
310 instead of a _
\bu_
\bs_
\be_
\br _
\bn_
\ba_
\bm_
\be, use _
\b#_
\bu_
\bi_
\bd. When running commands as
311 a _
\bu_
\bi_
\bd, many shells require that the '#' be escaped with a
312 backslash ('\'). Note that if the _
\bt_
\ba_
\br_
\bg_
\be_
\bt_
\bp_
\bw Defaults option
313 is set (see _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4)) it is not possible to run commands
314 with a uid not listed in the password database.
316 -V The -
\b-V
\bV (_
\bv_
\be_
\br_
\bs_
\bi_
\bo_
\bn) option causes s
\bsu
\bud
\bdo
\bo to print the version
317 number and exit. If the invoking user is already root the
318 -
\b-V
\bV option will print out a list of the defaults s
\bsu
\bud
\bdo
\bo was
319 compiled with as well as the machine's local network
322 -v If given the -
\b-v
\bv (_
\bv_
\ba_
\bl_
\bi_
\bd_
\ba_
\bt_
\be) option, s
\bsu
\bud
\bdo
\bo will update the
323 user's timestamp, prompting for the user's password if
324 necessary. This extends the s
\bsu
\bud
\bdo
\bo timeout for another 5
328 1.7.2 June 15, 2009 5
334 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
337 minutes (or whatever the timeout is set to in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs) but
338 does not run a command.
340 -- The -
\b--
\b- option indicates that s
\bsu
\bud
\bdo
\bo should stop processing
341 command line arguments. It is most useful in conjunction
342 with the -
\b-s
\bs option.
344 Environment variables to be set for the command may also be passed on
345 the command line in the form of V
\bVA
\bAR
\bR=_
\bv_
\ba_
\bl_
\bu_
\be, e.g.
346 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
347 line are subject to the same restrictions as normal environment
348 variables with one important exception. If the _
\bs_
\be_
\bt_
\be_
\bn_
\bv option is set in
349 _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs, the command to be run has the SETENV tag set or the command
350 matched is ALL, the user may set variables that would overwise be
351 forbidden. See _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) for more information.
353 R
\bRE
\bET
\bTU
\bUR
\bRN
\bN V
\bVA
\bAL
\bLU
\bUE
\bES
\bS
354 Upon successful execution of a program, the exit status from s
\bsu
\bud
\bdo
\bo will
355 simply be the exit status of the program that was executed.
357 Otherwise, s
\bsu
\bud
\bdo
\bo quits with an exit value of 1 if there is a
358 configuration/permission problem or if s
\bsu
\bud
\bdo
\bo cannot execute the given
359 command. In the latter case the error string is printed to stderr. If
360 s
\bsu
\bud
\bdo
\bo cannot _
\bs_
\bt_
\ba_
\bt(2) one or more entries in the user's PATH an error is
361 printed on stderr. (If the directory does not exist or if it is not
362 really a directory, the entry is ignored and no error is printed.)
363 This should not happen under normal circumstances. The most common
364 reason for _
\bs_
\bt_
\ba_
\bt(2) to return "permission denied" is if you are running
365 an automounter and one of the directories in your PATH is on a machine
366 that is currently unreachable.
368 S
\bSE
\bEC
\bCU
\bUR
\bRI
\bIT
\bTY
\bY N
\bNO
\bOT
\bTE
\bES
\bS
369 s
\bsu
\bud
\bdo
\bo tries to be safe when executing external commands.
371 There are two distinct ways to deal with environment variables. By
372 default, the _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs option is enabled. This causes commands
373 to be executed with a minimal environment containing TERM, PATH, HOME,
374 SHELL, LOGNAME, USER and USERNAME in addition to variables from the
375 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
376 options. There is effectively a whitelist for environment variables.
378 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
379 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
380 inherited from the invoking process. In this case, _
\be_
\bn_
\bv_
\b__
\bc_
\bh_
\be_
\bc_
\bk and
381 _
\be_
\bn_
\bv_
\b__
\bd_
\be_
\bl_
\be_
\bt_
\be behave like a blacklist. Since it is not possible to
382 blacklist all potentially dangerous environment variables, use of the
383 default _
\be_
\bn_
\bv_
\b__
\br_
\be_
\bs_
\be_
\bt behavior is encouraged.
385 In all cases, environment variables with a value beginning with () are
386 removed as they could be interpreted as b
\bba
\bas
\bsh
\bh functions. The list of
387 environment variables that s
\bsu
\bud
\bdo
\bo allows or denies is contained in the
388 output of sudo -V when run as root.
390 Note that the dynamic linker on most operating systems will remove
394 1.7.2 June 15, 2009 6
400 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
403 variables that can control dynamic linking from the environment of
404 setuid executables, including s
\bsu
\bud
\bdo
\bo. Depending on the operating system
405 this may include _RLD*, DYLD_*, LD_*, LDR_*, LIBPATH, SHLIB_PATH, and
406 others. These type of variables are removed from the environment
407 before s
\bsu
\bud
\bdo
\bo even begins execution and, as such, it is not possible for
408 s
\bsu
\bud
\bdo
\bo to preserve them.
410 To prevent command spoofing, s
\bsu
\bud
\bdo
\bo checks "." and "" (both denoting
411 current directory) last when searching for a command in the user's PATH
412 (if one or both are in the PATH). Note, however, that the actual PATH
413 environment variable is _
\bn_
\bo_
\bt modified and is passed unchanged to the
414 program that s
\bsu
\bud
\bdo
\bo executes.
416 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
417 by default) and ignore the directory's contents if it is not owned by
418 root or if it is writable by a user other than root. On systems that
419 allow non-root users to give away files via _
\bc_
\bh_
\bo_
\bw_
\bn(2), if the timestamp
420 directory is located in a directory writable by anyone (e.g., _
\b/_
\bt_
\bm_
\bp), it
421 is possible for a user to create the timestamp directory before s
\bsu
\bud
\bdo
\bo is
422 run. However, because s
\bsu
\bud
\bdo
\bo checks the ownership and mode of the
423 directory and its contents, the only damage that can be done is to
424 "hide" files by putting them in the timestamp dir. This is unlikely to
425 happen since once the timestamp dir is owned by root and inaccessible
426 by any other user, the user placing files there would be unable to get
427 them back out. To get around this issue you can use a directory that
428 is not world-writable for the timestamps (_
\b/_
\bv_
\ba_
\br_
\b/_
\ba_
\bd_
\bm_
\b/_
\bs_
\bu_
\bd_
\bo for instance)
429 or create _
\b/_
\bv_
\ba_
\br_
\b/_
\br_
\bu_
\bn_
\b/_
\bs_
\bu_
\bd_
\bo with the appropriate owner (root) and
430 permissions (0700) in the system startup files.
432 s
\bsu
\bud
\bdo
\bo will not honor timestamps set far in the future. Timestamps with
433 a date greater than current_time + 2 * TIMEOUT will be ignored and sudo
434 will log and complain. This is done to keep a user from creating
435 his/her own timestamp with a bogus date on systems that allow users to
438 Please note that s
\bsu
\bud
\bdo
\bo will normally only log the command it explicitly
439 runs. If a user runs a command such as sudo su or sudo sh, subsequent
440 commands run from that shell will _
\bn_
\bo_
\bt be logged, nor will s
\bsu
\bud
\bdo
\bo's access
441 control affect them. The same is true for commands that offer shell
442 escapes (including most editors). Because of this, care must be taken
443 when giving users access to commands via s
\bsu
\bud
\bdo
\bo to verify that the
444 command does not inadvertently give the user an effective root shell.
445 For more information, please see the PREVENTING SHELL ESCAPES section
446 in _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4).
448 E
\bEN
\bNV
\bVI
\bIR
\bRO
\bON
\bNM
\bME
\bEN
\bNT
\bT
449 s
\bsu
\bud
\bdo
\bo utilizes the following environment variables:
451 EDITOR Default editor to use in -
\b-e
\be (sudoedit) mode if neither
452 SUDO_EDITOR nor VISUAL is set
454 HOME In -
\b-s
\bs or -
\b-H
\bH mode (or if sudo was configured with the
455 --enable-shell-sets-home option), set to homedir of the
460 1.7.2 June 15, 2009 7
466 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
469 PATH Set to a sane value if the _
\bs_
\be_
\bc_
\bu_
\br_
\be_
\b__
\bp_
\ba_
\bt_
\bh sudoers option
472 SHELL Used to determine shell to run with -s option
474 SUDO_ASKPASS Specifies the path to a helper program used to read the
475 password if no terminal is available or if the -A
478 SUDO_COMMAND Set to the command run by sudo
480 SUDO_EDITOR Default editor to use in -
\b-e
\be (sudoedit) mode
482 SUDO_GID Set to the group ID of the user who invoked sudo
484 SUDO_PROMPT Used as the default password prompt
486 SUDO_PS1 If set, PS1 will be set to its value for the program
489 SUDO_UID Set to the user ID of the user who invoked sudo
491 SUDO_USER Set to the login of the user who invoked sudo
493 USER Set to the target user (root unless the -
\b-u
\bu option is
496 VISUAL Default editor to use in -
\b-e
\be (sudoedit) mode if
497 SUDO_EDITOR is not set
500 _
\b/_
\be_
\bt_
\bc_
\b/_
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs List of who can run what
502 _
\b/_
\bv_
\ba_
\br_
\b/_
\br_
\bu_
\bn_
\b/_
\bs_
\bu_
\bd_
\bo Directory containing timestamps
504 _
\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
507 E
\bEX
\bXA
\bAM
\bMP
\bPL
\bLE
\bES
\bS
508 Note: the following examples assume suitable _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) entries.
510 To get a file listing of an unreadable directory:
512 $ sudo ls /usr/local/protected
514 To list the home directory of user yaz on a machine where the file
515 system holding ~yaz is not exported as root:
517 $ sudo -u yaz ls ~yaz
519 To edit the _
\bi_
\bn_
\bd_
\be_
\bx_
\b._
\bh_
\bt_
\bm_
\bl file as user www:
521 $ sudo -u www vi ~www/htdocs/index.html
526 1.7.2 June 15, 2009 8
532 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
535 To view system logs only accessible to root and users in the adm group:
537 $ sudo -g adm view /var/log/syslog
539 To run an editor as jim with a different primary group:
541 $ sudo -u jim -g audio vi ~jim/sound.txt
543 To shutdown a machine:
545 $ sudo shutdown -r +15 "quick reboot"
547 To make a usage listing of the directories in the /home partition.
548 Note that this runs the commands in a sub-shell to make the cd and file
551 $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
553 S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
554 _
\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),
555 _
\bv_
\bi_
\bs_
\bu_
\bd_
\bo(1m)
557 A
\bAU
\bUT
\bTH
\bHO
\bOR
\bRS
\bS
558 Many people have worked on s
\bsu
\bud
\bdo
\bo over the years; this version consists
559 of code written primarily by:
563 See the HISTORY file in the s
\bsu
\bud
\bdo
\bo distribution or visit
564 http://www.sudo.ws/sudo/history.html for a short history of s
\bsu
\bud
\bdo
\bo.
566 C
\bCA
\bAV
\bVE
\bEA
\bAT
\bTS
\bS
567 There is no easy way to prevent a user from gaining a root shell if
568 that user is allowed to run arbitrary commands via s
\bsu
\bud
\bdo
\bo. Also, many
569 programs (such as editors) allow the user to run commands via shell
570 escapes, thus avoiding s
\bsu
\bud
\bdo
\bo's checks. However, on most systems it is
571 possible to prevent shell escapes with s
\bsu
\bud
\bdo
\bo's _
\bn_
\bo_
\be_
\bx_
\be_
\bc functionality.
572 See the _
\bs_
\bu_
\bd_
\bo_
\be_
\br_
\bs(4) manual for details.
574 It is not meaningful to run the cd command directly via sudo, e.g.,
576 $ sudo cd /usr/local/protected
578 since when the command exits the parent process (your shell) will still
579 be the same. Please see the EXAMPLES section for more information.
581 If users have sudo ALL there is nothing to prevent them from creating
582 their own program that gives them a root shell regardless of any '!'
583 elements in the user specification.
585 Running shell scripts via s
\bsu
\bud
\bdo
\bo can expose the same kernel bugs that
586 make setuid shell scripts unsafe on some operating systems (if your OS
587 has a /dev/fd/ directory, setuid shell scripts are generally safe).
592 1.7.2 June 15, 2009 9
598 SUDO(1m) MAINTENANCE COMMANDS SUDO(1m)
602 If you feel you have found a bug in s
\bsu
\bud
\bdo
\bo, please submit a bug report at
603 http://www.sudo.ws/sudo/bugs/
605 S
\bSU
\bUP
\bPP
\bPO
\bOR
\bRT
\bT
606 Limited free support is available via the sudo-users mailing list, see
607 http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
610 D
\bDI
\bIS
\bSC
\bCL
\bLA
\bAI
\bIM
\bME
\bER
\bR
611 s
\bsu
\bud
\bdo
\bo is provided ``AS IS'' and any express or implied warranties,
612 including, but not limited to, the implied warranties of
613 merchantability and fitness for a particular purpose are disclaimed.
614 See the LICENSE file distributed with s
\bsu
\bud
\bdo
\bo or
615 http://www.sudo.ws/sudo/license.html for complete details.
658 1.7.2 June 15, 2009 10