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su(1M)			System Administration Commands			su(1M)

NAME
       su - become superuser or	another	user

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

DESCRIPTION
       The su command allows one to become another user	without	logging	off or
       to assume a role. The default user name is root (superuser).

       To use su, the appropriate password must	be supplied  (unless  the  in-
       voker  is  already  root). If the password is correct, su creates a new
       shell process that has the real and effective user ID, group  IDs,  and
       supplementary  group list set to	those of the specified username. Addi-
       tionally, the new shell's project ID is set to the default  project  ID
       of   the	  specified   user.   See   getdefaultproj(3PROJECT),  setpro-
       ject(3PROJECT).	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)).  If superuser privilege  is
       requested  and  the  shell  for	the  superuser cannot be invoked using
       exec(2),	/sbin/sh is used as a fallback.	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 re-
       stricted	shell.

       To create a login environment, the command "su -" does the following:

	 o  In addition	to what	is already propagated, the LC* and LANG	 envi-
	    ronment  variables	from the specified user's environment are also
	    propagated.

	 o  Propagate TZ from the user's environment. If TZ is	not  found  in
	    the	user's environment, su uses the	TZ value from the TIMEZONE pa-
	    rameter found in /etc/default/login.

	 o  Set	MAIL to	/var/mail/new_user.

       If the first argument to	su is a	dash  (-),  the	 environment  will  be
       changed to what would be	expected if the	user actually logged in	as the
       specified user. Otherwise, the environment is passed  along,  with  the
       exception of $PATH,  which is controlled	by PATH	and SUPATH in /etc/de-
       fault/su.

       All attempts to become another user using su are	logged in the log file
       /var/adm/sulog (see sulog(4)).

SECURITY
       su  uses	pam(3PAM) with the service name	su for authentication, account
       management, and credential establishment.

EXAMPLES
       Example 1: Becoming User	bin While Retaining Your  Previously  Exported
       Environment

       To  become  user	 bin while retaining your previously exported environ-
       ment, execute:

       example%	su bin

       Example 2: Becoming User	bin and	Changing to bin's Login	Environment

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

       example%	su - bin

       Example	3:  Executing  command with user bin's Environment and Permis-
       sions

       To execute command with the temporary environment  and  permissions  of
       user bin, type:

       example%	su - bin -c "command args"

ENVIRONMENT VARIABLES
       Variables  with	LD_  prefix are	removed	for security reasons. Thus, su
       bin will	not retain previously exported variables with LD_ prefix while
       becoming	user bin.

       If  any of the LC_* variables ( LC_CTYPE, LC_MESSAGES, LC_TIME, LC_COL-
       LATE, LC_NUMERIC, and LC_MONETARY) (see environ(5)) are not set in  the
       environment,  the operational behavior of su for	each corresponding lo-
       cale category is	determined by the value	of the LANG environment	 vari-
       able. 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 lo-
		       cale. 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  it-
		       self (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 in this file 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  con-
					       sole.

			       PATH	       Default path. (/usr/bin:)

			       SUPATH	       Default	path for a user	invok-
					       ing	su	to	 root.
					       (/usr/sbin:/usr/bin)

			       SYSLOG	       Determines   whether  the  sys-
					       log(3C)	  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 generated
					       for  su's  to  other users, and
					       LOG_CRIT	messages are generated
					       for failed su attempts.

       /etc/default/login      the default parameters in this file are:

			       TIMEZONE	       Sets  the  TZ environment vari-
					       able of the shell.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       csh(1),	env(1),	 ksh(1),  login(1),  roles(1),	 sh(1),	  syslogd(1M),
       exec(2),	  getdefaultproj(3PROJECT),  setproject(3PROJECT),  pam(3PAM),
       pam_authenticate(3PAM),	   pam_acct_mgmt(3PAM),	    pam_setcred(3PAM),
       pam.conf(4),   passwd(4),   profile(4),	 sulog(4),   syslog(3C),   at-
       tributes(5), environ(5)

SunOS 5.10			  26 Feb 2004				su(1M)

NAME | SYNOPSIS | DESCRIPTION | SECURITY | EXAMPLES | ENVIRONMENT VARIABLES | FILES | ATTRIBUTES | SEE ALSO

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