su(1M)                Maintenance Commands                 su(1M)



NAME
     su - become super-user or another user

SYNOPSIS
     su [ - ] [ username [ arg ... ] ]

AVAILABILITY
     SUNWcsr

DESCRIPTION
     su allows one to become another user  without  logging  off.
     The default user name is root (super-user).

     To use su, the appropriate password must be supplied (unless
     the  invoker  is already root).  If the password is correct,
     su creates a new shell process that has the real and  effec-
     tive user ID, group IDs, and supplementary group list set to
     those of the specified username.  The new shell will be  the
     shell  specified  in  the shell field of username's password
     file entry (see  passwd(4)).   If  no  shell  is  specified,
     /usr/bin/sh  is  used (see sh(1)).  To return to normal user
     ID privileges, type an EOF character (CTRL-D)  to  exit  the
     new shell.

     Any additional arguments  given  on  the  command  line  are
     passed to the new shell.  When using programs such as sh, an
     arg of the form -c string executes string  using  the  shell
     and an arg of -r gives the user a restricted shell.

     If the first argument to su is ` - ' (dash), the environment
     will  be changed to what would be expected if the user actu-
     ally logged in as the specified user.  This is  accomplished
     by invoking the program used as the shell with a first argu-
     ment value whose initial character is `  -  '  (dash),  thus
     simulating  a login.  If the first argument to su is not ` -
     ' (dash), the environment is passed  along  unchanged,  with
     the  exception  of  $PATH,  which  is controlled by PATH and
     SUPATH in /etc/default/su.

     All attempts to become another user using su are  logged  in
     the log file /var/adm/sulog.

EXAMPLES
     To become user bin while retaining your previously  exported
     environment, execute:
          example% su bin

     To become user bin but change the environment to what  would
     be expected if bin had originally logged in, execute:
          example% su - bin

     To execute command with the temporary environment  and  per-
     missions of user bin, type:
         example% su - bin -c "command args"

ENVIRONMENT
     If any  of  the  LC_*  variables  (  LC_CTYPE,  LC_MESSAGES,
     LC_TIME,  LC_COLLATE,  LC_NUMERIC,  and  LC_MONETARY  ) (see
     environ(5)) are not set in the environment, the  operational
     behavior  of  su  for  each corresponding locale category is
     determined by the value of the  LANG  environment  variable.
     If LC_ALL is set, its contents are used to override both the
     LANG and the other LC_* variables.  If  none  of  the  above
     variables  are set in the environment, the "C"  (U.S. style)
     locale determines how su behaves.

     LC_CTYPE
          Determines how su handles characters. When LC_CTYPE  is
          set  to  a  valid value, su can display and handle text
          and filenames  containing  valid  characters  for  that
          locale.  su  can  display and handle Extended Unix Code
          (EUC) characters where any individual character can  be
          1,  2,  or 3 bytes wide. su can also handle EUC charac-
          ters of 1, 2, or more column widths. In the "C" locale,
          only characters from ISO 8859-1 are valid.

     LC_MESSAGES
          Determines how diagnostic and informative messages  are
          presented.  This includes the language and style of the
          messages, and the correct form of affirmative and nega-
          tive  responses.   In  the "C" locale, the messages are
          presented in the default  form  found  in  the  program
          itself (in most cases, U.S. English).

FILES
     $HOME/.profile      user's login commands for sh and ksh
     /etc/passwd         system's password file
     /etc/profile        system-wide sh and ksh login commands
     /var/adm/sulog      log file
     /etc/default/su     the default parameters that reside  here
                         are:

          SULOG:              If defined, all attempts to  su  to
                              another  user  are  logged  in  the
                              indicated file.
          CONSOLE:            If defined, all attempts to  su  to
                              root are logged on the console.
          PATH:               Default path. (/usr/bin:)
          SUPATH:             Default path for a user invoking su
                              to root.  (/usr/sbin:/usr/bin)
          SYSLOG:             Determines  whether  the  syslog(3)
                              LOG_AUTH facility should be used to
                              log  all  su  attempts.  LOG_NOTICE
                              messages  are generated for su's to
                              root, LOG_INFO  messages  are  gen-
                              erated for su's to other users, and
                              LOG_CRIT messages are generated for
                              failed su attempts.

SEE ALSO
     csh(1), env(1), ksh(1), login(1), sh(1),  syslogd(1M),  sys-
     log(3), passwd(4), profile(4), environ(5)

SunOS 5.4           Last change: 14 Sep 1992