Programming

I am writing a C app on a FreeBSD 6.0 box which acts as a multi-threaded proxy server. It accepts a number of connections from remote PC's and moves text data from those connection out thru a single port to another server (destination) so that it appears as if only one machine is connected to the destination server. I have a requirement that the proxy servers' connection to the destination sometimes be a telnet connection.

I thought that this would work:

<snip>
...
FILE * fp = popen("telnet destination", "w");
...
</snip>

and then each thread when it needed access would attempt a lock,yada yada yada...

My problem is I cannot find a way to send the username/password in the telnet command and it appears that I might have wait for a prompt, send the username then wait for another prompt and send the password. This could get complicated as different destination servers might have different prompts!

Maybe I've been looking at this too long and can't see a simple solution.

Any comments?

There is no simple solution, unless occaisional failure is ok. In that case, put in sleep(3) or whatever after the popen(), then send the username. Then another sleep. This works a lot of the time. I have used this technique in shell scripts.