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 prop-
	    agated.

	 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 parame-
	    ter 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 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 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 5.10							    26 Feb 2004 							    su(1M)