Restriction for more than one user

Shell Programming and Scripting
1

How do l restrict more than one users on a multiple programming environment using the c shell profile. That is if a user is log-on on one terminal the system should be able to prompt a message if the users attempt to log on on another terminal. I user openserver 5.0.4 with dummy terminals, and also intelligent workstation using telnet.

Thanks

Kayode

2

Here's one you could try:

Restrict number of logins allowed for a user

To restrict multiple logins, place the following lines in the users .profile 

# Limit number of logins allowed
Times_allowed=2
Time_in=`who | grep $LOGNAME | wc -l`
if [ $Time_in -gt "$Times_allowed" ]
then
  echo "$LOGNAME is already logged in $Times_allowed times!"
  exit
  exec /bin/login
fi

Then chmod 444 and chown root .profile
3

Just an FYI on the script above - you will never get the chance to "exec /bin/login" if you exit right before.
It shouldn't matter though - when you logout, another should be spawned.

4

I didn't write that program, so I don't know for sure, but isn't it just forcing the user to logoff (exit command) and then providing another prompt so that some different user could potentially log on?

5

Hello! Mr oombera

Thanks for the script. However, l made a mistaken of the type of shell script l have on my system. It is Bourne Shell and not C shell.
I tried running the above script on my system but l am prompt with the following errors:

-rsh : who : not found
-rsh : grep : not found
-rsh : wc : not found
-rsh : test : argument expected

Does it mean that C Shell script can't run on Bourne Shell script?

Thanks

Kayode

6

oombera, inittab and getty takes care of respawning the login prompt after a user exits, so you dont have to worry about providing another login prompt.

7

norsk hedensk, I understand what you're saying... maybe the script was written for an older system? maybe the programmer has a habit of including unneeded code? :slight_smile:

kayode, I'm not sure why it's giving you those errors.. try including #!/bin/sh at the top of the script.. other than that, those commands are pretty common on all unices.. unless they weren't installed on your system somehow..

Can you go to a command prompt and type any of them? For example:
who | grep <your_user_name>
wc <some_file>

8

Hi oombera

Thanks the script really work l mean perfectly.

Thanks

kayode