Re: telnet with keypress and errmsg problem

Notes on timeout:

do run the code scrap you provide: Lack of providing $cmd, lack of information of service to connect to, lack of providing module use statements, use of != instead ne for string comparison, lack of closing quote (both in final print). Just a quick edit-down for posting will bite you and those you ask. Reliably. Every time.
I've used the mail daemon as example service for my test. http / port 80 is also quite telnet-friendly.
the key to your problem is to remember that modules can create errors and choose to die or carp. Use eval{} to avoid that. That way the script continues beyond the timeouting waitfor. So of course the die and prints didn't trigger.
Note that there's a second $?, this time in the shell/invoking process (i.e. outside of your perl script): print $? or echo $? showing a value other than 0 would have alerted you to the fact that your script didn't exit as expected (fall-of-the-end-of-the-world aka implied exit(0)).
This holds at least for Unix and should also hold for cygwin. No bets on windows cmd. On Unix/Cygwin do consider including $? in your $PS1 shell prompt.

#start input of commands in telnet
#----------------------------------
$|=1;
use Net::Telnet;
$telnet=new Net::Telnet;
$telnet->port(25);
$telnet->open("localhost");
#$telnet->waitfor('/\# $/i');
warn "W220 follows\n";
$telnet->waitfor('/220/i');
$cmd="\n";
$telnet->print($cmd); 
#@output=$telnet->waitfor('/Press any key to continue \(Q to quit\)/')
+; 
warn "W500 follows\n";
# @output is actually the chars from the mailserver following
# code 220 excl. until code 500 incl.
@output=$telnet->waitfor('/500/'); 
warn "Pc - (a 502 SMTP code, I'd assume)\n";
$telnet->print('c'); #virtually press c key 
#@output2=$telnet->waitfor('/\# $/i');
#push(@output,@output2); 
warn "O==".join("\n",@output,"")."==\n";
warn "Wtimeout follows\n";
# create a deliberate error for error logging
# PJ waitfor will ALWAYS DIE ANYWAY -> USE e.g. eval{}
# PJ a failed waitfor dies w/o something of interest in $fault, $? or 
+$!
eval{
   warn "1", $fault=$telnet->waitfor('/dfs=l,gdmgll<>ifdgoij$/i');
}; 
warn "2$?\n"; # unused by waitfor
warn "3$!\n"; # unused by waitfor
warn "4", do{$fault=$telnet->errmsg},"\n"; # pattern match timed-out
$telnet->close;
if ($fault ne "") {
   print "you got an error $fault\n";
}
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The output for me annoying a postfix mailer daemon is:

W220 follows
W500 follows
Pc - (a 502 SMTP code, I'd assume)
O== anuurn.compact ESMTP Postfix (Ubuntu)

500
==
Wtimeout follows
20
3
4pattern match timed-out
you got an error pattern match timed-out
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