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 invoker 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.
       Additionally,  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 restricted shell.

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

	   o	  In addition to what is already propagated, the LC* and LANG environment 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
		  parameter 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/default/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 environment, 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 Permissions

       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_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 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 locale. su can display and handle Extended Unix Code (EUC) characters where	any  indi-
		      vidual  character can be 1, 2, or 3 bytes wide. su can also handle EUC characters 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 negative 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 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 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(3C) LOG_AUTH facility should be used to log all su attempts. LOG_NOTICE mes-
					sages  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 variable 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), attributes(5),
       environ(5)

SunOS 5.11							    26 Feb 2004 							    su(1M)