path: root/doc/sudo.cat

SUDO(1m)                     System Manager's Manual                    SUDO(1m)

NNAAMMEE
     ssuuddoo, ssuuddooeeddiitt - execute a command as another user

SSYYNNOOPPSSIISS
     ssuuddoo --hh | --KK | --kk | --VV
     ssuuddoo --vv [--AAkknnSS] [--aa _t_y_p_e] [--gg _g_r_o_u_p] [--hh _h_o_s_t] [--pp _p_r_o_m_p_t] [--uu _u_s_e_r]
     ssuuddoo --ll [--AAkknnSS] [--aa _t_y_p_e] [--gg _g_r_o_u_p] [--hh _h_o_s_t] [--pp _p_r_o_m_p_t] [--UU _u_s_e_r]
          [--uu _u_s_e_r] [_c_o_m_m_a_n_d]
     ssuuddoo [--AAbbEEHHnnPPSS] [--aa _t_y_p_e] [--CC _n_u_m] [--cc _c_l_a_s_s] [--gg _g_r_o_u_p] [--hh _h_o_s_t]
          [--pp _p_r_o_m_p_t] [--rr _r_o_l_e] [--tt _t_y_p_e] [--TT _t_i_m_e_o_u_t] [--uu _u_s_e_r] [_V_A_R=_v_a_l_u_e]
          [--ii | --ss] [_c_o_m_m_a_n_d]
     ssuuddooeeddiitt [--AAkknnSS] [--aa _t_y_p_e] [--CC _n_u_m] [--cc _c_l_a_s_s] [--gg _g_r_o_u_p] [--hh _h_o_s_t]
              [--pp _p_r_o_m_p_t] [--TT _t_i_m_e_o_u_t] [--uu _u_s_e_r] _f_i_l_e _._._.

DDEESSCCRRIIPPTTIIOONN
     ssuuddoo allows a permitted user to execute a _c_o_m_m_a_n_d as the superuser or
     another user, as specified by the security policy.  The invoking user's
     real (_n_o_t effective) user ID is used to determine the user name with
     which to query the security policy.

     ssuuddoo supports a plugin architecture for security policies and
     input/output logging.  Third parties can develop and distribute their own
     policy and I/O logging plugins to work seamlessly with the ssuuddoo front
     end.  The default security policy is _s_u_d_o_e_r_s, which is configured via the
     file _/_e_t_c_/_s_u_d_o_e_r_s, or via LDAP.  See the _P_l_u_g_i_n_s section for more
     information.

     The security policy determines what privileges, if any, a user has to run
     ssuuddoo.  The policy may require that users authenticate themselves with a
     password or another authentication mechanism.  If authentication is
     required, ssuuddoo will exit if the user's password is not entered within a
     configurable time limit.  This limit is policy-specific; the default
     password prompt timeout for the _s_u_d_o_e_r_s security policy is 5 minutes.

     Security policies may support credential caching to allow the user to run
     ssuuddoo again for a period of time without requiring authentication.  The
     _s_u_d_o_e_r_s policy caches credentials for 5 minutes, unless overridden in
     sudoers(4).  By running ssuuddoo with the --vv option, a user can update the
     cached credentials without running a _c_o_m_m_a_n_d.

     When invoked as ssuuddooeeddiitt, the --ee option (described below), is implied.

     Security policies may log successful and failed attempts to use ssuuddoo.  If
     an I/O plugin is configured, the running command's input and output may
     be logged as well.

     The options are as follows:

     --AA, ----aasskkppaassss
                 Normally, if ssuuddoo requires a password, it will read it from
                 the user's terminal.  If the --AA (_a_s_k_p_a_s_s) option is
                 specified, a (possibly graphical) helper program is executed
                 to read the user's password and output the password to the
                 standard output.  If the SUDO_ASKPASS environment variable is
                 set, it specifies the path to the helper program.  Otherwise,
                 if sudo.conf(4) contains a line specifying the askpass
                 program, that value will be used.  For example:

                     # Path to askpass helper program
                     Path askpass /usr/X11R6/bin/ssh-askpass

                 If no askpass program is available, ssuuddoo will exit with an
                 error.

     --aa _t_y_p_e, ----aauutthh--ttyyppee=_t_y_p_e
                 Use the specified BSD authentication _t_y_p_e when validating the
                 user, if allowed by _/_e_t_c_/_l_o_g_i_n_._c_o_n_f.  The system
                 administrator may specify a list of sudo-specific
                 authentication methods by adding an "auth-sudo" entry in
                 _/_e_t_c_/_l_o_g_i_n_._c_o_n_f.  This option is only available on systems
                 that support BSD authentication.

     --bb, ----bbaacckkggrroouunndd
                 Run the given command in the background.  Note that it is not
                 possible to use shell job control to manipulate background
                 processes started by ssuuddoo.  Most interactive commands will
                 fail to work properly in background mode.

     --CC _n_u_m, ----cclloossee--ffrroomm=_n_u_m
                 Close all file descriptors greater than or equal to _n_u_m
                 before executing a command.  Values less than three are not
                 permitted.  By default, ssuuddoo will close all open file
                 descriptors other than standard input, standard output and
                 standard error when executing a command.  The security policy
                 may restrict the user's ability to use this option.  The
                 _s_u_d_o_e_r_s policy only permits use of the --CC option when the
                 administrator has enabled the _c_l_o_s_e_f_r_o_m___o_v_e_r_r_i_d_e option.

     --cc _c_l_a_s_s, ----llooggiinn--ccllaassss=_c_l_a_s_s
                 Run the command with resource limits and scheduling priority
                 of the specified login _c_l_a_s_s.  The _c_l_a_s_s argument can be
                 either a class name as defined in _/_e_t_c_/_l_o_g_i_n_._c_o_n_f, or a
                 single `-' character.  If _c_l_a_s_s is --, the default login class
                 of the target user will be used.  Otherwise, the command must
                 be run as the superuser (user ID 0), or ssuuddoo must be run from
                 a shell that is already running as the superuser.  If the
                 command is being run as a login shell, additional
                 _/_e_t_c_/_l_o_g_i_n_._c_o_n_f settings, such as the umask and environment
                 variables, will be applied, if present.  This option is only
                 available on systems with BSD login classes.

     --EE, ----pprreesseerrvvee--eennvv
                 Indicates to the security policy that the user wishes to
                 preserve their existing environment variables.  The security
                 policy may return an error if the user does not have
                 permission to preserve the environment.

     ----pprreesseerrvvee--eennvv==lliisstt
                 Indicates to the security policy that the user wishes to add
                 the comma-separated list of environment variables to those
                 preserved from the user's environment.  The security policy
                 may return an error if the user does not have permission to
                 preserve the environment.

     --ee, ----eeddiitt  Edit one or more files instead of running a command.  In lieu
                 of a path name, the string "sudoedit" is used when consulting
                 the security policy.  If the user is authorized by the
                 policy, the following steps are taken:

                  1.   Temporary copies are made of the files to be edited
                       with the owner set to the invoking user.

                  2.   The editor specified by the policy is run to edit the
                       temporary files.  The _s_u_d_o_e_r_s policy uses the
                       SUDO_EDITOR, VISUAL and EDITOR environment variables
                       (in that order).  If none of SUDO_EDITOR, VISUAL or
                       EDITOR are set, the first program listed in the _e_d_i_t_o_r
                       sudoers(4) option is used.

                  3.   If they have been modified, the temporary files are
                       copied back to their original location and the
                       temporary versions are removed.

                 To help prevent the editing of unauthorized files, the
                 following restrictions are enforced unless explicitly allowed
                 by the security policy:

                  ++oo  Symbolic links may not be edited (version 1.8.15 and
                     higher).

                  ++oo  Symbolic links along the path to be edited are not
                     followed when the parent directory is writable by the
                     invoking user unless that user is root (version 1.8.16
                     and higher).

                  ++oo  Files located in a directory that is writable by the
                     invoking user may not be edited unless that user is root
                     (version 1.8.16 and higher).

                 Users are never allowed to edit device special files.

                 If the specified file does not exist, it will be created.
                 Note that unlike most commands run by _s_u_d_o, the editor is run
                 with the invoking user's environment unmodified.  If, for
                 some reason, ssuuddoo is unable to update a file with its edited
                 version, the user will receive a warning and the edited copy
                 will remain in a temporary file.

     --gg _g_r_o_u_p, ----ggrroouupp=_g_r_o_u_p
                 Run the command with the primary group set to _g_r_o_u_p instead
                 of the primary group specified by the target user's password
                 database entry.  The _g_r_o_u_p may be either a group name or a
                 numeric group ID (GID) prefixed with the `#' character (e.g.,
                 #0 for GID 0).  When running a command as a GID, many shells
                 require that the `#' be escaped with a backslash (`\').  If
                 no --uu option is specified, the command will be run as the
                 invoking user.  In either case, the primary group will be set
                 to _g_r_o_u_p.  The _s_u_d_o_e_r_s policy permits any of the target
                 user's groups to be specified via the --gg option as long as
                 the --PP option is not in use.

     --HH, ----sseett--hhoommee
                 Request that the security policy set the HOME environment
                 variable to the home directory specified by the target user's
                 password database entry.  Depending on the policy, this may
                 be the default behavior.

     --hh, ----hheellpp  Display a short help message to the standard output and exit.

     --hh _h_o_s_t, ----hhoosstt=_h_o_s_t
                 Run the command on the specified _h_o_s_t if the security policy
                 plugin supports remote commands.  Note that the _s_u_d_o_e_r_s
                 plugin does not currently support running remote commands.
                 This may also be used in conjunction with the --ll option to
                 list a user's privileges for the remote host.

     --ii, ----llooggiinn
                 Run the shell specified by the target user's password
                 database entry as a login shell.  This means that login-
                 specific resource files such as _._p_r_o_f_i_l_e, _._b_a_s_h___p_r_o_f_i_l_e or
                 _._l_o_g_i_n will be read by the shell.  If a command is specified,
                 it is passed to the shell for execution via the shell's --cc
                 option.  If no command is specified, an interactive shell is
                 executed.  ssuuddoo attempts to change to that user's home
                 directory before running the shell.  The command is run with
                 an environment similar to the one a user would receive at log
                 in.  Note that most shells behave differently when a command
                 is specified as compared to an interactive session; consult
                 the shell's manual for details.  The _C_o_m_m_a_n_d _e_n_v_i_r_o_n_m_e_n_t
                 section in the sudoers(4) manual documents how the --ii option
                 affects the environment in which a command is run when the
                 _s_u_d_o_e_r_s policy is in use.

     --KK, ----rreemmoovvee--ttiimmeessttaammpp
                 Similar to the --kk option, except that it removes the user's
                 cached credentials entirely and may not be used in
                 conjunction with a command or other option.  This option does
                 not require a password.  Not all security policies support
                 credential caching.

     --kk, ----rreesseett--ttiimmeessttaammpp
                 When used without a command, invalidates the user's cached
                 credentials.  In other words, the next time ssuuddoo is run a
                 password will be required.  This option does not require a
                 password and was added to allow a user to revoke ssuuddoo
                 permissions from a _._l_o_g_o_u_t file.

                 When used in conjunction with a command or an option that may
                 require a password, this option will cause ssuuddoo to ignore the
                 user's cached credentials.  As a result, ssuuddoo will prompt for
                 a password (if one is required by the security policy) and
                 will not update the user's cached credentials.

                 Not all security policies support credential caching.

     --ll, ----lliisstt  If no _c_o_m_m_a_n_d is specified, list the allowed (and forbidden)
                 commands for the invoking user (or the user specified by the
                 --UU option) on the current host.  A longer list format is used
                 if this option is specified multiple times and the security
                 policy supports a verbose output format.

                 If a _c_o_m_m_a_n_d is specified and is permitted by the security
                 policy, the fully-qualified path to the command is displayed
                 along with any command line arguments.  If a _c_o_m_m_a_n_d is
                 specified but not allowed by the policy, ssuuddoo will exit with
                 a status value of 1.

     --nn, ----nnoonn--iinntteerraaccttiivvee
                 Avoid prompting the user for input of any kind.  If a
                 password is required for the command to run, ssuuddoo will
                 display an error message and exit.

     --PP, ----pprreesseerrvvee--ggrroouuppss
                 Preserve the invoking user's group vector unaltered.  By
                 default, the _s_u_d_o_e_r_s policy will initialize the group vector
                 to the list of groups the target user is a member of.  The
                 real and effective group IDs, however, are still set to match
                 the target user.

     --pp _p_r_o_m_p_t, ----pprroommpptt=_p_r_o_m_p_t
                 Use a custom password prompt with optional escape sequences.
                 The following percent (`%') escape sequences are supported by
                 the _s_u_d_o_e_r_s policy:

                 %H  expanded to the host name including the domain name (on
                     if the machine's host name is fully qualified or the _f_q_d_n
                     option is set in sudoers(4))

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

                 %p  expanded to the name of the user whose password is being
                     requested (respects the _r_o_o_t_p_w, _t_a_r_g_e_t_p_w, and _r_u_n_a_s_p_w
                     flags in sudoers(4))

                 %U  expanded to the login name of the user the command will
                     be run as (defaults to root unless the --uu option is also
                     specified)

                 %u  expanded to the invoking user's login name

                 %%  two consecutive `%' characters are collapsed into a
                     single `%' character

                 The custom prompt will override the default prompt specified
                 by either the security policy or the SUDO_PROMPT environment
                 variable.  On systems that use PAM, the custom prompt will
                 also override the prompt specified by a PAM module unless the
                 _p_a_s_s_p_r_o_m_p_t___o_v_e_r_r_i_d_e flag is disabled in _s_u_d_o_e_r_s.

     --rr _r_o_l_e, ----rroollee=_r_o_l_e
                 Run the command with an SELinux security context that
                 includes the specified _r_o_l_e.

     --SS, ----ssttddiinn
                 Write the prompt to the standard error and read the password
                 from the standard input instead of using the terminal device.

     --ss, ----sshheellll
                 Run the shell specified by the SHELL environment variable if
                 it is set or the shell specified by the invoking user's
                 password database entry.  If a command is specified, it is
                 passed to the shell for execution via the shell's --cc option.
                 If no command is specified, an interactive shell is executed.
                 Note that most shells behave differently when a command is
                 specified as compared to an interactive session; consult the
                 shell's manual for details.

     --tt _t_y_p_e, ----ttyyppee=_t_y_p_e
                 Run the command with an SELinux security context that
                 includes the specified _t_y_p_e.  If no _t_y_p_e is specified, the
                 default type is derived from the role.

     --UU _u_s_e_r, ----ootthheerr--uusseerr=_u_s_e_r
                 Used in conjunction with the --ll option to list the privileges
                 for _u_s_e_r instead of for the invoking user.  The security
                 policy may restrict listing other users' privileges.  The
                 _s_u_d_o_e_r_s policy only allows root or a user with the ALL
                 privilege on the current host to use this option.

     --TT _t_i_m_e_o_u_t, ----ccoommmmaanndd--ttiimmeeoouutt=_t_i_m_e_o_u_t
                 Used to set a timeout for the command.  If the timeout
                 expires before the command has exited, the command will be
                 terminated.  The security policy may restrict the ability to
                 set command timeouts.  The _s_u_d_o_e_r_s policy requires that user-
                 specified timeouts be explicitly enabled.

     --uu _u_s_e_r, ----uusseerr=_u_s_e_r
                 Run the command as a user other than the default target user
                 (usually _r_o_o_t).  The _u_s_e_r may be either a user name or a
                 numeric user ID (UID) prefixed with the `#' character (e.g.,
                 #0 for UID 0).  When running commands as a UID, many shells
                 require that the `#' be escaped with a backslash (`\').  Some
                 security policies may restrict UIDs to those listed in the
                 password database.  The _s_u_d_o_e_r_s policy allows UIDs that are
                 not in the password database as long as the _t_a_r_g_e_t_p_w option
                 is not set.  Other security policies may not support this.

     --VV, ----vveerrssiioonn
                 Print the ssuuddoo version string as well as the version string
                 of the security policy plugin and any I/O plugins.  If the
                 invoking user is already root the --VV option will display the
                 arguments passed to configure when ssuuddoo was built and plugins
                 may display more verbose information such as default options.

     --vv, ----vvaalliiddaattee
                 Update the user's cached credentials, authenticating the user
                 if necessary.  For the _s_u_d_o_e_r_s plugin, this extends the ssuuddoo
                 timeout for another 5 minutes by default, but does not run a
                 command.  Not all security policies support cached
                 credentials.

     ----          The ---- option indicates that ssuuddoo should stop processing
                 command line arguments.

     Environment variables to be set for the command may also be passed on the
     command line in the form of _V_A_R=_v_a_l_u_e, e.g.,
     LD_LIBRARY_PATH=_/_u_s_r_/_l_o_c_a_l_/_p_k_g_/_l_i_b.  Variables passed on the command line
     are subject to restrictions imposed by the security policy plugin.  The
     _s_u_d_o_e_r_s policy subjects variables passed on the command line to the same
     restrictions as normal environment variables with one important
     exception.  If the _s_e_t_e_n_v option is set in _s_u_d_o_e_r_s, the command to be run
     has the SETENV tag set or the command matched is ALL, the user may set
     variables that would otherwise be forbidden.  See sudoers(4) for more
     information.

CCOOMMMMAANNDD EEXXEECCUUTTIIOONN
     When ssuuddoo executes a command, the security policy specifies the execution
     environment for the command.  Typically, the real and effective user and
     group and IDs are set to match those of the target user, as specified in
     the password database, and the group vector is initialized based on the
     group database (unless the --PP option was specified).

     The following parameters may be specified by security policy:

     ++oo  real and effective user ID

     ++oo  real and effective group ID

     ++oo  supplementary group IDs

     ++oo  the environment list

     ++oo  current working directory

     ++oo  file creation mode mask (umask)

     ++oo  SELinux role and type

     ++oo  Solaris project

     ++oo  Solaris privileges

     ++oo  BSD login class

     ++oo  scheduling priority (aka nice value)

   PPrroocceessss mmooddeell
     There are two distinct ways ssuuddoo can run a command.

     If an I/O logging plugin is configured or if the security policy
     explicitly requests it, a new pseudo-terminal ("pty") is allocated and
     fork(2) is used to create a second ssuuddoo process, referred to as the
     _m_o_n_i_t_o_r.  The _m_o_n_i_t_o_r creates a new terminal session with itself as the
     leader and the pty as its controlling terminal, calls fork(2), sets up
     the execution environment as described above, and then uses the execve(2)
     system call to run the command in the child process.  The _m_o_n_i_t_o_r exists
     to relay job control signals between the user's existing terminal and the
     pty the command is being run in.  This makes it possible to suspend and
     resume the command.  Without the monitor, the command would be in what
     POSIX terms an "orphaned process group" and it would not receive any job
     control signals from the kernel.  When the command exits or is terminated
     by a signal, the _m_o_n_i_t_o_r passes the command's exit status to the main
     ssuuddoo process and exits.  After receiving the command's exit status, the
     main ssuuddoo passes the command's exit status to the security policy's close
     function and exits.

     If no pty is used, ssuuddoo calls fork(2), sets up the execution environment
     as described above, and uses the execve(2) system call to run the command
     in the child process.  The main ssuuddoo process waits until the command has
     completed, then passes the command's exit status to the security policy's
     close function and exits.  As a special case, if the policy plugin does
     not define a close function, ssuuddoo will execute the command directly
     instead of calling fork(2) first.  The _s_u_d_o_e_r_s policy plugin will only
     define a close function when I/O logging is enabled, a pty is required,
     or the _p_a_m___s_e_s_s_i_o_n or _p_a_m___s_e_t_c_r_e_d options are enabled.  Note that
     _p_a_m___s_e_s_s_i_o_n and _p_a_m___s_e_t_c_r_e_d are enabled by default on systems using PAM.

   SSiiggnnaall hhaannddlliinngg
     When the command is run as a child of the ssuuddoo process, ssuuddoo will relay
     signals it receives to the command.  The SIGINT and SIGQUIT signals are
     only relayed when the command is being run in a new pty or when the
     signal was sent by a user process, not the kernel.  This prevents the
     command from receiving SIGINT twice each time the user enters control-C.
     Some signals, such as SIGSTOP and SIGKILL, cannot be caught and thus will
     not be relayed to the command.  As a general rule, SIGTSTP should be used
     instead of SIGSTOP when you wish to suspend a command being run by ssuuddoo.

     As a special case, ssuuddoo will not relay signals that were sent by the
     command it is running.  This prevents the command from accidentally
     killing itself.  On some systems, the reboot(1m) command sends SIGTERM to
     all non-system processes other than itself before rebooting the system.
     This prevents ssuuddoo from relaying the SIGTERM signal it received back to
     reboot(1m), which might then exit before the system was actually rebooted,
     leaving it in a half-dead state similar to single user mode.  Note,
     however, that this check only applies to the command run by ssuuddoo and not
     any other processes that the command may create.  As a result, running a
     script that calls reboot(1m) or shutdown(1m) via ssuuddoo may cause the system
     to end up in this undefined state unless the reboot(1m) or shutdown(1m) are
     run using the eexxeecc() family of functions instead of ssyysstteemm() (which
     interposes a shell between the command and the calling process).

     If no I/O logging plugins are loaded and the policy plugin has not
     defined a cclloossee() function, set a command timeout or required that the
     command be run in a new pty, ssuuddoo may execute the command directly
     instead of running it as a child process.

   PPlluuggiinnss
     Plugins may be specified via Plugin directives in the sudo.conf(4) file.
     They may be loaded as dynamic shared objects (on systems that support
     them), or compiled directly into the ssuuddoo binary.  If no sudo.conf(4)
     file is present, or it contains no Plugin lines, ssuuddoo will use the
     traditional _s_u_d_o_e_r_s security policy and I/O logging.  See the
     sudo.conf(4) manual for details of the _/_e_t_c_/_s_u_d_o_._c_o_n_f file and the
     sudo_plugin(4) manual for more information about the ssuuddoo plugin
     architecture.

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

     If the --ll option was specified without a command, ssuuddoo will exit with a
     value of 0 if the user is allowed to run ssuuddoo and they authenticated
     successfully (as required by the security policy).  If a command is
     specified with the --ll option, the exit value will only be 0 if the
     command is permitted by the security policy, otherwise it will be 1.

     If there is an authentication failure, a configuration/permission problem
     or if the given command cannot be executed, ssuuddoo exits with a value of 1.
     In the latter case, the error string is printed to the standard error.
     If ssuuddoo cannot stat(2) one or more entries in the user's PATH, an error
     is printed to the standard error.  (If the directory does not exist or if
     it is not really a directory, the entry is ignored and no error is
     printed.)  This should not happen under normal circumstances.  The most
     common reason for stat(2) to return "permission denied" is if you are
     running an automounter and one of the directories in your PATH is on a
     machine that is currently unreachable.

SSEECCUURRIITTYY NNOOTTEESS
     ssuuddoo tries to be safe when executing external commands.

     To prevent command spoofing, ssuuddoo checks "." and "" (both denoting
     current directory) last when searching for a command in the user's PATH
     (if one or both are in the PATH).  Note, however, that the actual PATH
     environment variable is _n_o_t modified and is passed unchanged to the
     program that ssuuddoo executes.

     Users should _n_e_v_e_r be granted ssuuddoo privileges to execute files that are
     writable by the user or that reside in a directory that is writable by
     the user.  If the user can modify or replace the command there is no way
     to limit what additional commands they can run.

     Please note that ssuuddoo will normally only log the command it explicitly
     runs.  If a user runs a command such as sudo su or sudo sh, subsequent
     commands run from that shell are not subject to ssuuddoo's security policy.
     The same is true for commands that offer shell escapes (including most
     editors).  If I/O logging is enabled, subsequent commands will have their
     input and/or output logged, but there will not be traditional logs for
     those commands.  Because of this, care must be taken when giving users
     access to commands via ssuuddoo to verify that the command does not
     inadvertently give the user an effective root shell.  For more
     information, please see the _P_r_e_v_e_n_t_i_n_g _s_h_e_l_l _e_s_c_a_p_e_s section in
     sudoers(4).

     To prevent the disclosure of potentially sensitive information, ssuuddoo
     disables core dumps by default while it is executing (they are re-enabled
     for the command that is run).  This historical practice dates from a time
     when most operating systems allowed setuid processes to dump core by
     default.  To aid in debugging ssuuddoo crashes, you may wish to re-enable
     core dumps by setting "disable_coredump" to false in the sudo.conf(4)
     file as follows:

           Set disable_coredump false

     See the sudo.conf(4) manual for more information.

EENNVVIIRROONNMMEENNTT
     ssuuddoo utilizes the following environment variables.  The security policy
     has control over the actual content of the command's environment.

     EDITOR           Default editor to use in --ee (sudoedit) mode if neither
                      SUDO_EDITOR nor VISUAL is set.

     MAIL             Set to the mail spool of the target user when the --ii
                      option is specified or when _e_n_v___r_e_s_e_t is enabled in
                      _s_u_d_o_e_r_s (unless MAIL is present in the _e_n_v___k_e_e_p list).

     HOME             Set to the home directory of the target user when the --ii
                      or --HH options are specified, when the --ss option is
                      specified and _s_e_t___h_o_m_e is set in _s_u_d_o_e_r_s, when
                      _a_l_w_a_y_s___s_e_t___h_o_m_e is enabled in _s_u_d_o_e_r_s, or when _e_n_v___r_e_s_e_t
                      is enabled in _s_u_d_o_e_r_s and _H_O_M_E is not present in the
                      _e_n_v___k_e_e_p list.

     LOGNAME          Set to the login name of the target user when the --ii
                      option is specified, when the _s_e_t___l_o_g_n_a_m_e option is
                      enabled in _s_u_d_o_e_r_s or when the _e_n_v___r_e_s_e_t option is
                      enabled in _s_u_d_o_e_r_s (unless LOGNAME is present in the
                      _e_n_v___k_e_e_p list).

     PATH             May be overridden by the security policy.

     SHELL            Used to determine shell to run with --ss option.

     SUDO_ASKPASS     Specifies the path to a helper program used to read the
                      password if no terminal is available or if the --AA option
                      is specified.

     SUDO_COMMAND     Set to the command run by sudo.

     SUDO_EDITOR      Default editor to use in --ee (sudoedit) mode.

     SUDO_GID         Set to the group ID of the user who invoked sudo.

     SUDO_PROMPT      Used as the default password prompt unless the --pp option
                      was specified.

     SUDO_PS1         If set, PS1 will be set to its value for the program
                      being run.

     SUDO_UID         Set to the user ID of the user who invoked sudo.

     SUDO_USER        Set to the login name of the user who invoked sudo.

     USER             Set to the same value as LOGNAME, described above.

     VISUAL           Default editor to use in --ee (sudoedit) mode if
                      SUDO_EDITOR is not set.

FFIILLEESS
     _/_e_t_c_/_s_u_d_o_._c_o_n_f            ssuuddoo front end configuration

EEXXAAMMPPLLEESS
     Note: the following examples assume a properly configured security
     policy.

     To get a file listing of an unreadable directory:

           $ sudo ls /usr/local/protected

     To list the home directory of user yaz on a machine where the file system
     holding ~yaz is not exported as root:

           $ sudo -u yaz ls ~yaz

     To edit the _i_n_d_e_x_._h_t_m_l file as user www:

           $ sudoedit -u www ~www/htdocs/index.html

     To view system logs only accessible to root and users in the adm group:

           $ sudo -g adm more /var/log/syslog

     To run an editor as jim with a different primary group:

           $ sudoedit -u jim -g audio ~jim/sound.txt

     To shut down a machine:

           $ sudo shutdown -r +15 "quick reboot"

     To make a usage listing of the directories in the /home partition.  Note
     that this runs the commands in a sub-shell to make the cd and file
     redirection work.

           $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"

DDIIAAGGNNOOSSTTIICCSS
     Error messages produced by ssuuddoo include:

     editing files in a writable directory is not permitted
           By default, ssuuddooeeddiitt does not permit editing a file when any of the
           parent directories are writable by the invoking user.  This avoids
           a race condition that could allow the user to overwrite an
           arbitrary file.  See the _s_u_d_o_e_d_i_t___c_h_e_c_k_d_i_r option in sudoers(4) for
           more information.

     editing symbolic links is not permitted
           By default, ssuuddooeeddiitt does not follow symbolic links when opening
           files.  See the _s_u_d_o_e_d_i_t___f_o_l_l_o_w option in sudoers(4) for more
           information.

     effective uid is not 0, is sudo installed setuid root?
           ssuuddoo was not run with root privileges.  The ssuuddoo binary must be
           owned by the root user and have the Set-user-ID bit set.  Also, it
           must not be located on a file system mounted with the `nosuid'
           option or on an NFS file system that maps uid 0 to an unprivileged
           uid.

     effective uid is not 0, is sudo on a file system with the 'nosuid' option
           set or an NFS file system without root privileges?
           ssuuddoo was not run with root privileges.  The ssuuddoo binary has the
           proper owner and permissions but it still did not run with root
           privileges.  The most common reason for this is that the file
           system the ssuuddoo binary is located on is mounted with the `nosuid'
           option or it is an NFS file system that maps uid 0 to an
           unprivileged uid.

     fatal error, unable to load plugins
           An error occurred while loading or initializing the plugins
           specified in sudo.conf(4).

     invalid environment variable name
           One or more environment variable names specified via the --EE option
           contained an equal sign (`=').  The arguments to the --EE option
           should be environment variable names without an associated value.

     no password was provided
           When ssuuddoo tried to read the password, it did not receive any
           characters.  This may happen if no terminal is available (or the --SS
           option is specified) and the standard input has been redirected
           from _/_d_e_v_/_n_u_l_l.

     no tty present and no askpass program specified
           ssuuddoo needs to read the password but there is no mechanism available
           to do so.  A terminal is not present to read the password from,
           ssuuddoo has not been configured to read from the standard input, and
           no askpass program has been specified either via the --AA option or
           the SUDO_ASKPASS environment variable.

     no writable temporary directory found
           ssuuddooeeddiitt was unable to find a usable temporary directory in which
           to store its intermediate files.

     sudo must be owned by uid 0 and have the setuid bit set
           ssuuddoo was not run with root privileges.  The ssuuddoo binary does not
           have the correct owner or permissions.  It must be owned by the
           root user and have the Set-user-ID bit set.

     sudoedit is not supported on this platform
           It is only possible to run ssuuddooeeddiitt on systems that support setting
           the effective user-ID.

     timed out reading password
           The user did not enter a password before the password timeout (5
           minutes by default) expired.

     you do not exist in the passwd database
           Your user ID does not appear in the system passwd database.

     you may not specify environment variables in edit mode
           It is only possible to specify environment variables when running a
           command.  When editing a file, the editor is run with the user's
           environment unmodified.

SSEEEE AALLSSOO
     su(1), stat(2), login_cap(3), passwd(4), sudo.conf(4), sudo_plugin(4),
     sudoers(4), sudoreplay(1m), visudo(1m)

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

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

           Todd C. Miller

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

CCAAVVEEAATTSS
     There is no easy way to prevent a user from gaining a root shell if that
     user is allowed to run arbitrary commands via ssuuddoo.  Also, many programs
     (such as editors) allow the user to run commands via shell escapes, thus
     avoiding ssuuddoo's checks.  However, on most systems it is possible to
     prevent shell escapes with the sudoers(4) plugin's _n_o_e_x_e_c functionality.

     It is not meaningful to run the cd command directly via sudo, e.g.,

           $ sudo cd /usr/local/protected

     since when the command exits the parent process (your shell) will still
     be the same.  Please see the _E_X_A_M_P_L_E_S section for more information.

     Running shell scripts via ssuuddoo can expose the same kernel bugs that make
     setuid shell scripts unsafe on some operating systems (if your OS has a
     /dev/fd/ directory, setuid shell scripts are generally safe).

BBUUGGSS
     If you feel you have found a bug in ssuuddoo, please submit a bug report at
     https://bugzilla.sudo.ws/

SSUUPPPPOORRTT
     Limited free support is available via the sudo-users mailing list, see
     https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
     the archives.

DDIISSCCLLAAIIMMEERR
     ssuuddoo is provided "AS IS" and any express or implied warranties,
     including, but not limited to, the implied warranties of merchantability
     and fitness for a particular purpose are disclaimed.  See the LICENSE
     file distributed with ssuuddoo or https://www.sudo.ws/license.html for
     complete details.

Sudo 1.8.26                    November 25, 2018                   Sudo 1.8.26