Net::Telnet hangs after initiating reboot command

[iamsiju]

Hi,

I am facing a problem with the Perl Telnet Object. My Telnet Object hangs just after issueing reboot command on the remote host.

Please help me who faced this problem !!!

Thanks in advance

Siju Maliakkal

[miller]

Well, of course it will hang, as the telnet session will be dropped immediately after you tell the remote server to reboot. I don't know the best method to solve this, but one alternative would be to setup an alarm.

http://perldoc.perl.org/functions/alarm.html

I would also enclose that particular telnet command in an eval statement to trap the alarm call as well. Then do the appropriate cleanup associated with the fact that the telnet session is defunct. Something like this:

eval {
alarm 5;
$t->cmd("reboot");
alarm 0;
};
# Proceed with cleanup
 

[turbokat]

## I have tested this code on all Unix platforms (AIX, HP, Linux - All, Solaris)
## This is absolutely flawless
## Abhishek A. Kulkarni
 
use Net::Telnet;
use Net::Ping;
 
sub Reboot
{
        my ($hostname, $username, $password) = @_;
 
        print "\n Telnet for Reboot\n";
        my $telnetHandle = getTelnetHandle($hostname, $username, $password);
 
        print "\n Rebooting the machine \n";
 
        @output = remoteCommand("which reboot", $hostname, $username, $password);
 
        $command = $output[0];
        chomp($command);
        print "\n$command\n";
 
        $telnetHandle->cmd("$command");
        $telnetHandle->close;
 
        print "\n telnet handle closed \n";
 
        ## Verify if host is pinging for some time even after reboot command
        for($count=1;$count<=300;$count++)
        {
                if($ping->ping($hostname))
                {
                        print "\n host is still pinging \n";
                        sleep(1);
                }
                else
                {
                        print "\n Host went DOWN \n";
                        last;
                }
        }
        ## Verify if host has come up after reboot
        $Reboot = 0;
        for($count=1;$count<=180;$count++)
        {
                if($ping->ping($hostname))
                {
                        print "\n Host came UP\n";
                        $Reboot = 1;
                        last;
                }
                else
                {
                        print "#";
                        sleep(5);
                }
        }
 
        if($Reboot == 0)
        {
                print "\n Host did not come UP even after waiting for 15 mins \n";
        }
        ## Get telnet handle after reboot and return it to the calling subroutine
        $telnetHandle = getTelnetHandle($hostname,$username,$password);
        return $telnetHandle;
}
 
sub remoteCommand
{
        my ($command, $hostname, $username, $password) = @_;
        my $telnetHandle = getTelnetHandle($hostname, $username, $password);
 
        @output = $telnetHandle->cmd(String => $command,Timeout => 4000,Prompt => ' /[#] $/');
 
        return @output;
}
 
sub getTelnetHandle
{
        my ($hostname, $username, $password) = @_;
        my $prompt = '/#|$ $/';
        my $timeout = 10;
        my $errmode = "return";
        my $port = 23;
 
        $ping = Net::Ping->new();
 
        if ($ping->ping($hostname))
        {
                print "INFO: Host is reachable\n";
 
                $telnetHandle = new Net::Telnet (Errmode=>$errmode,Host=>$hostname,Prompt=>$prompt,Port=>$port,Timeout=>$timeout);
 
                $telnetHandle->open("$hostname");
 
                print "\n Telnet Handle Created \n";
 
                $telnetHandle->login(Name=>$username,Password=>$password,Errmode => $errmode,Timeout =>$timeout);
 
                $STDError = $telnetHandle->errmsg();
 
                if ($STDError)
                {
                        print "ERROR : $STDError";
                }
        }
        else
        {
                print "ERROR: Host is not reachable";
        }
        return $telnetHandle;
}

[numberwhun]

You need to please keep in mind the age of the question(s) that you are reading. This post is about 2 years old and I doubt the user is even monitoring it.

To that end, I am closing this thread.

Regards,

Jeff