telnet

[Wang Xueyan]

In our system, users have to telnet to the server to use our application. Many of them never exit when they left. That affect the server's performance. Is there any way to kill these idle telnetd or shell automatically?

[T G Manikandan · Accepted solution]

if the user default shell is ksh and sh you can use the /etc/profile
TMOUT=600(value in sec)



If their shell is csh
then

make entries in /etc/csh.login

set autologout=60(value in min)



Thanks

[Michael Tully]

The most used method is to set up either via the users .profile file a 'TMOUT=3600' or some or other time variant. The value is in seconds. Here is a snipet from the 'ksh' man page

TMOUT If set to a value greater than zero, the read built-in command terminates after TMOUTseconds when input is from a terminal. Otherwise, the shell will terminate if a line is not entered within the prescribed number of seconds while reading from a terminal. (Note that the shell can be compiled with a maximum bound for this value which cannot be exceeded.)

[Ravi_8]

Hi,

since those ppid will be set to 1, killing those processes wouldn't help. they vanish after a reboot. To avoid these follow the making entries as posted by Manikandan

[Michael Tully]

Beware of setting the TMOUT variable in /etc/profile. Doing this sets a basically a system wide variable for all users. The best way is to utilise the TMOUT function is via skeleton .profile with the variable instead.
You can create a skeleton .csh.login file for 'csh' users as well if required.

[Steven E. Protter]

TMEOUT won't work in some telnet applicatoins.

We use software AG natural and even if the user has timed out of the database natural doesn't time them out.

So I've had to write a custom program that does the following:

It reads the telnet user and checks a database utility for a login. If there is a match, it leaves them alone. If there is no match it nukes the pid of the natural session.

Sometimes you have to write your own tool to do the job.

P

[Wang Xueyan]

I got it. Thank you.