Annotation of embedaddon/sudo/doc/sudo.cat, revision 1.1.1.4

1.1.1.3   misho       1: SUDO(1m)                     System Manager's Manual                    SUDO(1m)
1.1       misho       2: 
                      3: NNAAMMEE
1.1.1.3   misho       4:      ssuuddoo, ssuuddooeeddiitt - execute a command as another user
1.1       misho       5: 
                      6: SSYYNNOOPPSSIISS
1.1.1.3   misho       7:      ssuuddoo --hh | --KK | --kk | --VV
                      8:      ssuuddoo --vv [--AAkknnSS] [--aa _a_u_t_h___t_y_p_e] [--gg _g_r_o_u_p _n_a_m_e | _#_g_i_d] [--pp _p_r_o_m_p_t]
                      9:           [--uu _u_s_e_r _n_a_m_e | _#_u_i_d]
                     10:      ssuuddoo --ll[_l] [--AAkknnSS] [--aa _a_u_t_h___t_y_p_e] [--gg _g_r_o_u_p _n_a_m_e | _#_g_i_d] [--pp _p_r_o_m_p_t]
                     11:           [--UU _u_s_e_r _n_a_m_e] [--uu _u_s_e_r _n_a_m_e | _#_u_i_d] [_c_o_m_m_a_n_d]
                     12:      ssuuddoo [--AAbbEEHHnnPPSS] [--aa _a_u_t_h___t_y_p_e] [--CC _f_d] [--cc _c_l_a_s_s | _-]
                     13:           [--gg _g_r_o_u_p _n_a_m_e | _#_g_i_d] [--pp _p_r_o_m_p_t] [--rr _r_o_l_e] [--tt _t_y_p_e]
                     14:           [--uu _u_s_e_r _n_a_m_e | _#_u_i_d] [VVAARR=_v_a_l_u_e] --ii | --ss [_c_o_m_m_a_n_d]
                     15:      ssuuddooeeddiitt [--AAnnSS] [--aa _a_u_t_h___t_y_p_e] [--CC _f_d] [--cc _c_l_a_s_s | _-]
                     16:               [--gg _g_r_o_u_p _n_a_m_e | _#_g_i_d] [--pp _p_r_o_m_p_t] [--uu _u_s_e_r _n_a_m_e | _#_u_i_d] file
                     17:               ...
1.1       misho      18: 
                     19: DDEESSCCRRIIPPTTIIOONN
1.1.1.3   misho      20:      ssuuddoo allows a permitted user to execute a _c_o_m_m_a_n_d as the superuser or
                     21:      another user, as specified by the security policy.
                     22: 
                     23:      ssuuddoo supports a plugin architecture for security policies and
                     24:      input/output logging.  Third parties can develop and distribute their own
                     25:      policy and I/O logging plugins to work seamlessly with the ssuuddoo front
                     26:      end.  The default security policy is _s_u_d_o_e_r_s, which is configured via the
1.1.1.4 ! misho      27:      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
1.1.1.3   misho      28:      information.
                     29: 
                     30:      The security policy determines what privileges, if any, a user has to run
                     31:      ssuuddoo.  The policy may require that users authenticate themselves with a
                     32:      password or another authentication mechanism.  If authentication is
                     33:      required, ssuuddoo will exit if the user's password is not entered within a
                     34:      configurable time limit.  This limit is policy-specific; the default
                     35:      password prompt timeout for the _s_u_d_o_e_r_s security policy is 5 minutes.
                     36: 
                     37:      Security policies may support credential caching to allow the user to run
                     38:      ssuuddoo again for a period of time without requiring authentication.  The
                     39:      _s_u_d_o_e_r_s policy caches credentials for 5 minutes, unless overridden in
                     40:      sudoers(4).  By running ssuuddoo with the --vv option, a user can update the
                     41:      cached credentials without running a _c_o_m_m_a_n_d.
                     42: 
                     43:      When invoked as ssuuddooeeddiitt, the --ee option (described below), is implied.
                     44: 
                     45:      Security policies may log successful and failed attempts to use ssuuddoo.  If
                     46:      an I/O plugin is configured, the running command's input and output may
                     47:      be logged as well.
                     48: 
                     49:      The options are as follows:
                     50: 
                     51:      --AA          Normally, if ssuuddoo requires a password, it will read it from
                     52:                  the user's terminal.  If the --AA (_a_s_k_p_a_s_s) option is
                     53:                  specified, a (possibly graphical) helper program is executed
                     54:                  to read the user's password and output the password to the
                     55:                  standard output.  If the SUDO_ASKPASS environment variable is
                     56:                  set, it specifies the path to the helper program.  Otherwise,
1.1.1.4 ! misho      57:                  if sudo.conf(4) contains a line specifying the askpass
1.1.1.3   misho      58:                  program, that value will be used.  For example:
                     59: 
                     60:                      # Path to askpass helper program
                     61:                      Path askpass /usr/X11R6/bin/ssh-askpass
                     62: 
                     63:                  If no askpass program is available, ssuuddoo will exit with an
                     64:                  error.
                     65: 
                     66:      --aa _t_y_p_e     The --aa (_a_u_t_h_e_n_t_i_c_a_t_i_o_n _t_y_p_e) option causes ssuuddoo to use the
                     67:                  specified authentication type when validating the user, as
                     68:                  allowed by _/_e_t_c_/_l_o_g_i_n_._c_o_n_f.  The system administrator may
                     69:                  specify a list of sudo-specific authentication methods by
                     70:                  adding an ``auth-sudo'' entry in _/_e_t_c_/_l_o_g_i_n_._c_o_n_f.  This
                     71:                  option is only available on systems that support BSD
                     72:                  authentication.
                     73: 
                     74:      --bb          The --bb (_b_a_c_k_g_r_o_u_n_d) option tells ssuuddoo to run the given
                     75:                  command in the background.  Note that if you use the --bb
                     76:                  option you cannot use shell job control to manipulate the
                     77:                  process.  Most interactive commands will fail to work
                     78:                  properly in background mode.
                     79: 
                     80:      --CC _f_d       Normally, ssuuddoo will close all open file descriptors other
                     81:                  than standard input, standard output and standard error.  The
                     82:                  --CC (_c_l_o_s_e _f_r_o_m) option allows the user to specify a starting
                     83:                  point above the standard error (file descriptor three).
                     84:                  Values less than three are not permitted.  The security
                     85:                  policy may restrict the user's ability to use the --CC option.
                     86:                  The _s_u_d_o_e_r_s policy only permits use of the --CC option when the
                     87:                  administrator has enabled the _c_l_o_s_e_f_r_o_m___o_v_e_r_r_i_d_e option.
                     88: 
                     89:      --cc _c_l_a_s_s    The --cc (_c_l_a_s_s) option causes ssuuddoo to run the specified
                     90:                  command with resources limited by the specified login class.
                     91:                  The _c_l_a_s_s argument can be either a class name as defined in
                     92:                  _/_e_t_c_/_l_o_g_i_n_._c_o_n_f, or a single `-' character.  Specifying a
                     93:                  _c_l_a_s_s of - indicates that the command should be run
                     94:                  restricted by the default login capabilities for the user the
                     95:                  command is run as.  If the _c_l_a_s_s argument specifies an
                     96:                  existing user class, the command must be run as root, or the
                     97:                  ssuuddoo command must be run from a shell that is already root.
                     98:                  This option is only available on systems with BSD login
                     99:                  classes.
                    100: 
                    101:      --EE          The --EE (_p_r_e_s_e_r_v_e _e_n_v_i_r_o_n_m_e_n_t) option indicates to the
                    102:                  security policy that the user wishes to preserve their
                    103:                  existing environment variables.  The security policy may
                    104:                  return an error if the --EE option is specified and the user
                    105:                  does not have permission to preserve the environment.
                    106: 
                    107:      --ee          The --ee (_e_d_i_t) option indicates that, instead of running a
                    108:                  command, the user wishes to edit one or more files.  In lieu
                    109:                  of a command, the string "sudoedit" is used when consulting
                    110:                  the security policy.  If the user is authorized by the
                    111:                  policy, the following steps are taken:
1.1       misho     112: 
1.1.1.3   misho     113:                   1.   Temporary copies are made of the files to be edited
1.1       misho     114:                        with the owner set to the invoking user.
                    115: 
1.1.1.3   misho     116:                   2.   The editor specified by the policy is run to edit the
1.1       misho     117:                        temporary files.  The _s_u_d_o_e_r_s policy uses the
                    118:                        SUDO_EDITOR, VISUAL and EDITOR environment variables
                    119:                        (in that order).  If none of SUDO_EDITOR, VISUAL or
                    120:                        EDITOR are set, the first program listed in the _e_d_i_t_o_r
1.1.1.3   misho     121:                        sudoers(4) option is used.
1.1       misho     122: 
1.1.1.3   misho     123:                   3.   If they have been modified, the temporary files are
1.1       misho     124:                        copied back to their original location and the
                    125:                        temporary versions are removed.
                    126: 
1.1.1.3   misho     127:                  If the specified file does not exist, it will be created.
                    128:                  Note that unlike most commands run by _s_u_d_o, the editor is run
                    129:                  with the invoking user's environment unmodified.  If, for
                    130:                  some reason, ssuuddoo is unable to update a file with its edited
                    131:                  version, the user will receive a warning and the edited copy
                    132:                  will remain in a temporary file.
                    133: 
                    134:      --gg _g_r_o_u_p    Normally, ssuuddoo runs a command with the primary group set to
                    135:                  the one specified by the password database for the user the
                    136:                  command is being run as (by default, root).  The --gg (_g_r_o_u_p)
                    137:                  option causes ssuuddoo to run the command with the primary group
                    138:                  set to _g_r_o_u_p instead.  To specify a _g_i_d instead of a _g_r_o_u_p
                    139:                  _n_a_m_e, use _#_g_i_d.  When running commands as a _g_i_d, many shells
                    140:                  require that the `#' be escaped with a backslash (`\').  If
                    141:                  no --uu option is specified, the command will be run as the
                    142:                  invoking user (not root).  In either case, the primary group
                    143:                  will be set to _g_r_o_u_p.
                    144: 
                    145:      --HH          The --HH (_H_O_M_E) option requests that the security policy set
                    146:                  the HOME environment variable to the home directory of the
                    147:                  target user (root by default) as specified by the password
                    148:                  database.  Depending on the policy, this may be the default
                    149:                  behavior.
                    150: 
                    151:      --hh          The --hh (_h_e_l_p) option causes ssuuddoo to print a short help
                    152:                  message to the standard output and exit.
                    153: 
                    154:      --ii [_c_o_m_m_a_n_d]
                    155:                  The --ii (_s_i_m_u_l_a_t_e _i_n_i_t_i_a_l _l_o_g_i_n) option runs the shell
                    156:                  specified by the password database entry of the target user
                    157:                  as a login shell.  This means that login-specific resource
                    158:                  files such as _._p_r_o_f_i_l_e or _._l_o_g_i_n will be read by the shell.
                    159:                  If a command is specified, it is passed to the shell for
                    160:                  execution via the shell's --cc option.  If no command is
                    161:                  specified, an interactive shell is executed.  ssuuddoo attempts
                    162:                  to change to that user's home directory before running the
                    163:                  shell.  The security policy shall initialize the environment
                    164:                  to a minimal set of variables, similar to what is present
                    165:                  when a user logs in.  The _C_o_m_m_a_n_d _E_n_v_i_r_o_n_m_e_n_t section in the
                    166:                  sudoers(4) manual documents how the --ii option affects the
                    167:                  environment in which a command is run when the _s_u_d_o_e_r_s policy
                    168:                  is in use.
                    169: 
                    170:      --KK          The --KK (sure _k_i_l_l) option is like --kk except that it removes
                    171:                  the user's cached credentials entirely and may not be used in
                    172:                  conjunction with a command or other option.  This option does
                    173:                  not require a password.  Not all security policies support
                    174:                  credential caching.
                    175: 
                    176:      --kk [_c_o_m_m_a_n_d]
                    177:                  When used alone, the --kk (_k_i_l_l) option to ssuuddoo invalidates the
                    178:                  user's cached credentials.  The next time ssuuddoo is run a
                    179:                  password will be required.  This option does not require a
                    180:                  password and was added to allow a user to revoke ssuuddoo
                    181:                  permissions from a _._l_o_g_o_u_t file.  Not all security policies
                    182:                  support credential caching.
                    183: 
                    184:                  When used in conjunction with a command or an option that may
                    185:                  require a password, the --kk option will cause ssuuddoo to ignore
                    186:                  the user's cached credentials.  As a result, ssuuddoo will prompt
                    187:                  for a password (if one is required by the security policy)
                    188:                  and will not update the user's cached credentials.
                    189: 
                    190:      --ll[ll] [_c_o_m_m_a_n_d]
                    191:                  If no _c_o_m_m_a_n_d is specified, the --ll (_l_i_s_t) option will list
                    192:                  the allowed (and forbidden) commands for the invoking user
                    193:                  (or the user specified by the --UU option) on the current host.
                    194:                  If a _c_o_m_m_a_n_d is specified and is permitted by the security
                    195:                  policy, the fully-qualified path to the command is displayed
                    196:                  along with any command line arguments.  If _c_o_m_m_a_n_d is
                    197:                  specified but not allowed, ssuuddoo will exit with a status value
                    198:                  of 1.  If the --ll option is specified with an _l argument (i.e.
                    199:                  --llll), or if --ll is specified multiple times, a longer list
                    200:                  format is used.
                    201: 
                    202:      --nn          The --nn (_n_o_n_-_i_n_t_e_r_a_c_t_i_v_e) option prevents ssuuddoo from prompting
                    203:                  the user for a password.  If a password is required for the
                    204:                  command to run, ssuuddoo will display an error message and exit.
                    205: 
                    206:      --PP          The --PP (_p_r_e_s_e_r_v_e _g_r_o_u_p _v_e_c_t_o_r) option causes ssuuddoo to preserve
                    207:                  the invoking user's group vector unaltered.  By default, the
                    208:                  _s_u_d_o_e_r_s policy will initialize the group vector to the list
                    209:                  of groups the target user is in.  The real and effective
                    210:                  group IDs, however, are still set to match the target user.
                    211: 
                    212:      --pp _p_r_o_m_p_t   The --pp (_p_r_o_m_p_t) option allows you to override the default
                    213:                  password prompt and use a custom one.  The following percent
                    214:                  (`%') escapes are supported by the _s_u_d_o_e_r_s policy:
                    215: 
                    216:                  %H  expanded to the host name including the domain name (on
                    217:                      if the machine's host name is fully qualified or the _f_q_d_n
                    218:                      option is set in sudoers(4))
                    219: 
                    220:                  %h  expanded to the local host name without the domain name
                    221: 
                    222:                  %p  expanded to the name of the user whose password is being
                    223:                      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
                    224:                      flags in sudoers(4))
                    225: 
                    226:                  %U  expanded to the login name of the user the command will
                    227:                      be run as (defaults to root unless the --uu option is also
                    228:                      specified)
                    229: 
                    230:                  %u  expanded to the invoking user's login name
                    231: 
                    232:                  %%  two consecutive `%' characters are collapsed into a
                    233:                      single `%' character
                    234: 
                    235:                  The prompt specified by the --pp option will override the
                    236:                  system password prompt on systems that support PAM unless the
                    237:                  _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.
                    238: 
                    239:      --rr _r_o_l_e     The --rr (_r_o_l_e) option causes the new (SELinux) security
                    240:                  context to have the role specified by _r_o_l_e.
                    241: 
                    242:      --SS          The --SS (_s_t_d_i_n) option causes ssuuddoo to read the password from
                    243:                  the standard input instead of the terminal device.  The
                    244:                  password must be followed by a newline character.
                    245: 
                    246:      --ss [_c_o_m_m_a_n_d]
                    247:                  The --ss (_s_h_e_l_l) option runs the shell specified by the SHELL
                    248:                  environment variable if it is set or the shell as specified
                    249:                  in the password database.  If a command is specified, it is
                    250:                  passed to the shell for execution via the shell's --cc option.
                    251:                  If no command is specified, an interactive shell is executed.
                    252: 
                    253:      --tt _t_y_p_e     The --tt (_t_y_p_e) option causes the new (SELinux) security
                    254:                  context to have the type specified by _t_y_p_e.  If no type is
                    255:                  specified, the default type is derived from the specified
                    256:                  role.
                    257: 
                    258:      --UU _u_s_e_r     The --UU (_o_t_h_e_r _u_s_e_r) option is used in conjunction with the --ll
                    259:                  option to specify the user whose privileges should be listed.
                    260:                  The security policy may restrict listing other users'
                    261:                  privileges.  The _s_u_d_o_e_r_s policy only allows root or a user
                    262:                  with the ALL privilege on the current host to use this
                    263:                  option.
                    264: 
                    265:      --uu _u_s_e_r     The --uu (_u_s_e_r) option causes ssuuddoo to run the specified command
                    266:                  as a user other than _r_o_o_t.  To specify a _u_i_d instead of a
                    267:                  _u_s_e_r _n_a_m_e, _#_u_i_d.  When running commands as a _u_i_d, many shells
                    268:                  require that the `#' be escaped with a backslash (`\').
                    269:                  Security policies may restrict _u_i_ds to those listed in the
                    270:                  password database.  The _s_u_d_o_e_r_s policy allows _u_i_ds that are
                    271:                  not in the password database as long as the _t_a_r_g_e_t_p_w option
                    272:                  is not set.  Other security policies may not support this.
                    273: 
                    274:      --VV          The --VV (_v_e_r_s_i_o_n) option causes ssuuddoo to print its version
                    275:                  string and the version string of the security policy plugin
                    276:                  and any I/O plugins.  If the invoking user is already root
                    277:                  the --VV option will display the arguments passed to configure
                    278:                  when ssuuddoo was built and plugins may display more verbose
                    279:                  information such as default options.
                    280: 
                    281:      --vv          When given the --vv (_v_a_l_i_d_a_t_e) option, ssuuddoo will update the
                    282:                  user's cached credentials, authenticating the user's password
                    283:                  if necessary.  For the _s_u_d_o_e_r_s plugin, this extends the ssuuddoo
                    284:                  timeout for another 5 minutes (or whatever the timeout is set
                    285:                  to by the security policy) but does not run a command.  Not
                    286:                  all security policies support cached credentials.
                    287: 
                    288:      ----          The ---- option indicates that ssuuddoo should stop processing
                    289:                  command line arguments.
                    290: 
                    291:      Environment variables to be set for the command may also be passed on the
                    292:      command line in the form of VVAARR=_v_a_l_u_e, e.g.
                    293:      LLDD__LLIIBBRRAARRYY__PPAATTHH=_/_u_s_r_/_l_o_c_a_l_/_p_k_g_/_l_i_b.  Variables passed on the command line
                    294:      are subject to the same restrictions as normal environment variables with
                    295:      one important exception.  If the _s_e_t_e_n_v option is set in _s_u_d_o_e_r_s, the
                    296:      command to be run has the SETENV tag set or the command matched is ALL,
                    297:      the user may set variables that would otherwise be forbidden.  See
                    298:      sudoers(4) for more information.
                    299: 
                    300: CCOOMMMMAANNDD EEXXEECCUUTTIIOONN
                    301:      When ssuuddoo executes a command, the security policy specifies the execution
1.1.1.4 ! misho     302:      environment for the command.  Typically, the real and effective uid and
1.1.1.3   misho     303:      gid are set to match those of the target user, as specified in the
                    304:      password database, and the group vector is initialized based on the group
                    305:      database (unless the --PP option was specified).
                    306: 
                    307:      The following parameters may be specified by security policy:
                    308: 
                    309:      oo   real and effective user ID
                    310: 
                    311:      oo   real and effective group ID
                    312: 
                    313:      oo   supplementary group IDs
                    314: 
                    315:      oo   the environment list
                    316: 
                    317:      oo   current working directory
                    318: 
                    319:      oo   file creation mode mask (umask)
                    320: 
                    321:      oo   SELinux role and type
                    322: 
                    323:      oo   Solaris project
                    324: 
                    325:      oo   Solaris privileges
                    326: 
                    327:      oo   BSD login class
                    328: 
                    329:      oo   scheduling priority (aka nice value)
                    330: 
                    331:    PPrroocceessss mmooddeell
                    332:      When ssuuddoo runs a command, it calls fork(2), sets up the execution
                    333:      environment as described above, and calls the execve system call in the
                    334:      child process.  The main ssuuddoo process waits until the command has
                    335:      completed, then passes the command's exit status to the security policy's
1.1.1.4 ! misho     336:      close function and exits.  If an I/O logging plugin is configured or if
        !           337:      the security policy explicitly requests it, a new  pseudo-terminal
        !           338:      (``pty'') is created and a second ssuuddoo process is used to relay job
        !           339:      control signals between the user's existing pty and the new pty the
        !           340:      command is being run in.  This extra process makes it possible to, for
        !           341:      example, suspend and resume the command.  Without it, the command would
        !           342:      be in what POSIX terms an ``orphaned process group'' and it would not
        !           343:      receive any job control signals.  As a special case, if the policy plugin
        !           344:      does not define a close function and no pty is required, ssuuddoo will
        !           345:      execute the command directly instead of calling fork(2) first.
1.1.1.3   misho     346: 
                    347:    SSiiggnnaall hhaannddlliinngg
                    348:      Because the command is run as a child of the ssuuddoo process, ssuuddoo will
                    349:      relay signals it receives to the command.  Unless the command is being
                    350:      run in a new pty, the SIGHUP, SIGINT and SIGQUIT signals are not relayed
                    351:      unless they are sent by a user process, not the kernel.  Otherwise, the
                    352:      command would receive SIGINT twice every time the user entered control-C.
                    353:      Some signals, such as SIGSTOP and SIGKILL, cannot be caught and thus will
                    354:      not be relayed to the command.  As a general rule, SIGTSTP should be used
                    355:      instead of SIGSTOP when you wish to suspend a command being run by ssuuddoo.
                    356: 
                    357:      As a special case, ssuuddoo will not relay signals that were sent by the
                    358:      command it is running.  This prevents the command from accidentally
                    359:      killing itself.  On some systems, the reboot(1m) command sends SIGTERM to
1.1.1.4 ! misho     360:      all non-system processes other than itself before rebooting the system.
1.1.1.3   misho     361:      This prevents ssuuddoo from relaying the SIGTERM signal it received back to
                    362:      reboot(1m), which might then exit before the system was actually rebooted,
                    363:      leaving it in a half-dead state similar to single user mode.  Note,
                    364:      however, that this check only applies to the command run by ssuuddoo and not
                    365:      any other processes that the command may create.  As a result, running a
                    366:      script that calls reboot(1m) or shutdown(1m) via ssuuddoo may cause the system
                    367:      to end up in this undefined state unless the reboot(1m) or shutdown(1m) are
                    368:      run using the eexxeecc() family of functions instead of ssyysstteemm() (which
                    369:      interposes a shell between the command and the calling process).
1.1       misho     370: 
1.1.1.4 ! misho     371:      If no I/O logging plugins are loaded and the policy plugin has not
        !           372:      defined a cclloossee() function, set a command timeout or required that the
        !           373:      command be run in a new pty, ssuuddoo may execute the command directly
        !           374:      instead of running it as a child process.
        !           375: 
        !           376:    PPlluuggiinnss
        !           377:      Plugins are dynamically loaded based on the contents of the sudo.conf(4)
        !           378:      file.  If no sudo.conf(4) file is present, or it contains no Plugin
        !           379:      lines, ssuuddoo will use the traditional _s_u_d_o_e_r_s security policy and I/O
        !           380:      logging.  See the sudo.conf(4) manual for details of the _/_e_t_c_/_s_u_d_o_._c_o_n_f
        !           381:      file and the sudo_plugin(1m) manual for more information about the ssuuddoo
        !           382:      plugin architecture.
1.1.1.2   misho     383: 
1.1.1.3   misho     384: EEXXIITT VVAALLUUEE
                    385:      Upon successful execution of a program, the exit status from _s_u_d_o will
                    386:      simply be the exit status of the program that was executed.
1.1       misho     387: 
1.1.1.3   misho     388:      Otherwise, ssuuddoo exits with a value of 1 if there is a
                    389:      configuration/permission problem or if ssuuddoo cannot execute the given
                    390:      command.  In the latter case the error string is printed to the standard
                    391:      error.  If ssuuddoo cannot stat(2) one or more entries in the user's PATH, an
                    392:      error is printed on stderr.  (If the directory does not exist or if it is
                    393:      not really a directory, the entry is ignored and no error is printed.)
                    394:      This should not happen under normal circumstances.  The most common
                    395:      reason for stat(2) to return ``permission denied'' is if you are running
                    396:      an automounter and one of the directories in your PATH is on a machine
                    397:      that is currently unreachable.
1.1       misho     398: 
                    399: SSEECCUURRIITTYY NNOOTTEESS
1.1.1.3   misho     400:      ssuuddoo tries to be safe when executing external commands.
1.1       misho     401: 
1.1.1.3   misho     402:      To prevent command spoofing, ssuuddoo checks "." and "" (both denoting
                    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 _n_o_t modified and is passed unchanged to the
                    406:      program that ssuuddoo executes.
                    407: 
                    408:      Please note that ssuuddoo will normally only log the command it explicitly
                    409:      runs.  If a user runs a command such as sudo su or sudo sh, subsequent
                    410:      commands run from that shell are not subject to ssuuddoo's security policy.
                    411:      The same is true for commands that offer shell escapes (including most
                    412:      editors).  If I/O logging is enabled, subsequent commands will have their
                    413:      input and/or output logged, but there will not be traditional logs for
                    414:      those commands.  Because of this, care must be taken when giving users
                    415:      access to commands via ssuuddoo to verify that the command does not
                    416:      inadvertently give the user an effective root shell.  For more
                    417:      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
                    418:      sudoers(4).
                    419: 
                    420:      To prevent the disclosure of potentially sensitive information, ssuuddoo
                    421:      disables core dumps by default while it is executing (they are re-enabled
                    422:      for the command that is run).  To aid in debugging ssuuddoo crashes, you may
                    423:      wish to re-enable core dumps by setting ``disable_coredump'' to false in
1.1.1.4 ! misho     424:      the sudo.conf(4) file as follows:
1.1.1.3   misho     425: 
                    426:            Set disable_coredump false
                    427: 
1.1.1.4 ! misho     428:      See the sudo.conf(4) manual for more information.
1.1.1.2   misho     429: 
1.1       misho     430: EENNVVIIRROONNMMEENNTT
1.1.1.3   misho     431:      ssuuddoo utilizes the following environment variables.  The security policy
                    432:      has control over the actual content of the command's environment.
1.1       misho     433: 
1.1.1.3   misho     434:      EDITOR           Default editor to use in --ee (sudoedit) mode if neither
                    435:                       SUDO_EDITOR nor VISUAL is set.
1.1       misho     436: 
1.1.1.3   misho     437:      MAIL             In --ii mode or when _e_n_v___r_e_s_e_t is enabled in _s_u_d_o_e_r_s, set
                    438:                       to the mail spool of the target user.
1.1       misho     439: 
1.1.1.3   misho     440:      HOME             Set to the home directory of the target user if --ii or --HH
                    441:                       are specified, _e_n_v___r_e_s_e_t or _a_l_w_a_y_s___s_e_t___h_o_m_e are set in
                    442:                       _s_u_d_o_e_r_s, or when the --ss option is specified and _s_e_t___h_o_m_e
                    443:                       is set in _s_u_d_o_e_r_s.
1.1       misho     444: 
1.1.1.3   misho     445:      PATH             May be overridden by the security policy.
1.1       misho     446: 
1.1.1.3   misho     447:      SHELL            Used to determine shell to run with --ss option.
1.1       misho     448: 
1.1.1.3   misho     449:      SUDO_ASKPASS     Specifies the path to a helper program used to read the
                    450:                       password if no terminal is available or if the --AA option
                    451:                       is specified.
1.1       misho     452: 
1.1.1.3   misho     453:      SUDO_COMMAND     Set to the command run by sudo.
1.1       misho     454: 
1.1.1.3   misho     455:      SUDO_EDITOR      Default editor to use in --ee (sudoedit) mode.
1.1       misho     456: 
1.1.1.3   misho     457:      SUDO_GID         Set to the group ID of the user who invoked sudo.
1.1       misho     458: 
1.1.1.3   misho     459:      SUDO_PROMPT      Used as the default password prompt.
1.1       misho     460: 
1.1.1.3   misho     461:      SUDO_PS1         If set, PS1 will be set to its value for the program
                    462:                       being run.
1.1       misho     463: 
1.1.1.3   misho     464:      SUDO_UID         Set to the user ID of the user who invoked sudo.
1.1       misho     465: 
1.1.1.3   misho     466:      SUDO_USER        Set to the login name of the user who invoked sudo.
1.1       misho     467: 
1.1.1.3   misho     468:      USER             Set to the target user (root unless the --uu option is
                    469:                       specified).
1.1       misho     470: 
1.1.1.3   misho     471:      VISUAL           Default editor to use in --ee (sudoedit) mode if
                    472:                       SUDO_EDITOR is not set.
1.1       misho     473: 
                    474: FFIILLEESS
1.1.1.3   misho     475:      _/_e_t_c_/_s_u_d_o_._c_o_n_f            ssuuddoo front end configuration
1.1       misho     476: 
                    477: EEXXAAMMPPLLEESS
1.1.1.3   misho     478:      Note: the following examples assume a properly configured security
                    479:      policy.
1.1       misho     480: 
1.1.1.3   misho     481:      To get a file listing of an unreadable directory:
1.1       misho     482: 
1.1.1.3   misho     483:            $ sudo ls /usr/local/protected
1.1       misho     484: 
1.1.1.3   misho     485:      To list the home directory of user yaz on a machine where the file system
                    486:      holding ~yaz is not exported as root:
1.1       misho     487: 
1.1.1.3   misho     488:            $ sudo -u yaz ls ~yaz
1.1       misho     489: 
1.1.1.3   misho     490:      To edit the _i_n_d_e_x_._h_t_m_l file as user www:
1.1       misho     491: 
1.1.1.3   misho     492:            $ sudo -u www vi ~www/htdocs/index.html
1.1       misho     493: 
1.1.1.3   misho     494:      To view system logs only accessible to root and users in the adm group:
1.1       misho     495: 
1.1.1.3   misho     496:            $ sudo -g adm view /var/log/syslog
1.1       misho     497: 
1.1.1.3   misho     498:      To run an editor as jim with a different primary group:
1.1       misho     499: 
1.1.1.3   misho     500:            $ sudo -u jim -g audio vi ~jim/sound.txt
1.1       misho     501: 
1.1.1.3   misho     502:      To shut down a machine:
1.1       misho     503: 
1.1.1.3   misho     504:            $ sudo shutdown -r +15 "quick reboot"
1.1       misho     505: 
1.1.1.3   misho     506:      To make a usage listing of the directories in the /home partition.  Note
                    507:      that this runs the commands in a sub-shell to make the cd and file
                    508:      redirection work.
1.1       misho     509: 
1.1.1.3   misho     510:            $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
1.1       misho     511: 
                    512: SSEEEE AALLSSOO
1.1.1.4 ! misho     513:      su(1), stat(2), login_cap(3), passwd(4), sudo.conf(4), sudoers(4),
1.1.1.3   misho     514:      sudo_plugin(1m), sudoreplay(1m), visudo(1m)
1.1       misho     515: 
1.1.1.3   misho     516: HHIISSTTOORRYY
                    517:      See the HISTORY file in the ssuuddoo distribution
                    518:      (http://www.sudo.ws/sudo/history.html) for a brief history of sudo.
1.1       misho     519: 
1.1.1.3   misho     520: AAUUTTHHOORRSS
                    521:      Many people have worked on ssuuddoo over the years; this version consists of
                    522:      code written primarily by:
1.1       misho     523: 
1.1.1.3   misho     524:            Todd C. Miller
1.1.1.2   misho     525: 
1.1.1.3   misho     526:      See the CONTRIBUTORS file in the ssuuddoo distribution
                    527:      (http://www.sudo.ws/sudo/contributors.html) for an exhaustive list of
                    528:      people who have contributed to ssuuddoo.
1.1       misho     529: 
                    530: CCAAVVEEAATTSS
1.1.1.3   misho     531:      There is no easy way to prevent a user from gaining a root shell if that
                    532:      user is allowed to run arbitrary commands via ssuuddoo.  Also, many programs
                    533:      (such as editors) allow the user to run commands via shell escapes, thus
                    534:      avoiding ssuuddoo's checks.  However, on most systems it is possible to
                    535:      prevent shell escapes with the sudoers(4) plugin's _n_o_e_x_e_c functionality.
                    536: 
                    537:      It is not meaningful to run the cd command directly via sudo, e.g.,
                    538: 
                    539:            $ sudo cd /usr/local/protected
                    540: 
                    541:      since when the command exits the parent process (your shell) will still
                    542:      be the same.  Please see the _E_X_A_M_P_L_E_S section for more information.
                    543: 
                    544:      Running shell scripts via ssuuddoo can expose the same kernel bugs that make
                    545:      setuid shell scripts unsafe on some operating systems (if your OS has a
                    546:      /dev/fd/ directory, setuid shell scripts are generally safe).
1.1       misho     547: 
                    548: BBUUGGSS
1.1.1.3   misho     549:      If you feel you have found a bug in ssuuddoo, please submit a bug report at
                    550:      http://www.sudo.ws/sudo/bugs/
1.1       misho     551: 
                    552: SSUUPPPPOORRTT
1.1.1.3   misho     553:      Limited free support is available via the sudo-users mailing list, see
                    554:      http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search the
                    555:      archives.
1.1       misho     556: 
                    557: DDIISSCCLLAAIIMMEERR
1.1.1.3   misho     558:      ssuuddoo is provided ``AS IS'' and any express or implied warranties,
                    559:      including, but not limited to, the implied warranties of merchantability
                    560:      and fitness for a particular purpose are disclaimed.  See the LICENSE
                    561:      file distributed with ssuuddoo or http://www.sudo.ws/sudo/license.html for
                    562:      complete details.
1.1       misho     563: 
1.1.1.4 ! misho     564: Sudo 1.8.7                      March 13, 2013                      Sudo 1.8.7

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