This is the README file for lock version 1.1
It has several improvements over the version 1.0, but some of the things
I wanted to add do not work. If I can I will try to add these in the next
version.

IF YOU ARE USING VERSION 1.0 OF THIS PROGRAM, I STRONGLY SUGGEST THAT YOU
UPGRADE TO THIS VERSION. VERSION 1.0 DID NOT ENCRYPT PASSWORDS WHILE THEY WERE
IN MEMORY. THIS IS POTENTIALLY A SECURITY HOLE. THIS HAS BEEN FIXED IN 1.1.

I am releasing the program under GNU General Public License.
The purpose of the program is to lock up a terminal while you are away.
You either specify the password on the command line or the program asks
you when it starts. You can also use the same password as you use to
login with the -p option. You need to enter the password to unlock. If you
don't remember the password, the only way to unlock is to kill the program
with SIGKILL. Use kill -9 program_id

The program syntax is simple:

	lock [password] [-p]

I do not recommend specifying the actual password on the command line. Other
users might be able to see it from a different terminal using the ps command.

If your system uses shadow passwords, you will need to make lock suid root
to use the -p option. If you don't have shadow passwords you might want to
comment out one line in the Makefile.

I have compiled and run this version of the program on a Sun Sparc running
SunOS 5.5.1 and on an SGI Indy running IRIX 6.2. I could not test the -p
option on the Sparc since it uses shadow passwords and I don't have root
privilidges there. The SGI does not use shadow passwords. Otherwise, the
program works on these platforms even though I get some warnings during
compilation. I didn't have any warnings while compiling on Linux.

I am told that the program also compiled and worked on an alpha-dec-osf4.0a
that doesn't use shadow passwords.

If anyone is able to run lock on these or other OS's, please tell me at
the e-mail address below.

Just in case, I am running Linux 2.0.33 with libc 5.4.33. I was using
gcc 2.7.2.3 to compile.

If you have any comments, questions or improvements for the program,
please contact me. I am currently working on the next version of the
program which will have more functionality.

Eugene Rabinovich
y-rabinovich@uchicago.edu