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.blank 2
.c;Eye Research Institute Submissions 
.blank 2
.c;coordinated by: 
.c; Bob Goldstein, Daniel P.B. Smith, Rivkah Stabiner
.blank 2
.c;Bob Goldstein, Daniel P.B. Smith, Rivkah Stabiner
.c;Eye Research Institute of Retina Foundation
.c;20 Staniford Street
.c;Boston, MA 02114
.c;(617) 742-3140
.s 1
DUPUSE.FOR is a FORTRAN program which prevents multiple
logins of the same username on the system.  There are several reasons
for wanting to do this:
.list 1
.le;It prevents a user from logging into one terminal, forgetting that
he or she has done so, and then logging into a second terminal.
.le;It discourages users from giving out their usernames and passwords
to other people if the two of them can't log in simultaneously.
.le;If a potential intruder has illegally obtained the username and
password of  legitimate user, he or she cannot log in when the legitimate
user is already logged in.
.end list
^&INSTALLATION of the system\&
.LIST 1
.le;Right now the program excludes users who have process names of
SYSTEM, CROISETU, and OPA0:.  If you wish, you may edit the DUPUSE.FOR
program so that it excludes the users you want to exclude.
.le;Compile and link the fortran program by executing the FORTLINK.COM
command procedure:
.literal

	$ @FORTLINK.COM
.end literal
.le;Copy the DUPUSE.EXE file over to the SYS$MANAGER directory and set 
protection so that the world can read and execute it.
.literal

	$ COPY DUPUSE.EXE SYS$SYSROOT:[SYSMGR]DUPUSE.EXE
	$ SET FILE/PRO=W:RE SYS$SYSROOT:[SYSMGR]DUPUSE.EXE
.end literal
.le;Install the program with WORLD privilege:
.literal

	$ INSTALL :== $sys$system:install/command_mode
	$ INSTALL
	ADD/PRIV=WORLD SYS$MANAGER:DUPUSE
	EXIT

.end literal
You should also edit SYSTARTUP.COM so it automatically re-installs the 
program each time the system comes up.
.le;Edit SYLOGIN.COM to include the following line, so that the program
is run whenever users log in:
.literal

	$ RUN SYS$MANAGER:DUPUSE
.end literal
.end list