Telnet Script exits if any of the machine is un-accessible

kumarnaveen has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I have a list of around 150 servers to access. I need to write a telnet script to get the information from the nodes. I wrote a script which gets the IP address and tries to telnet to machine and gets the information. This script exits if suppose any of the server is un-accessible. Please have a look into this script and let me know how can I solve this.

use Net::Telnet();

    print "count is $i\n";

    open (OUT,">D:/PERL/TELNET_OUTPUT.txt") or die "could not open new
+.txt\n";
    open(FILE, "D:/PERL/ip.txt") || die "Failed\n";

foreach $x (<FILE>)
{
    $telnet = Net::Telnet-> new(Host =>"$x",timeout =>13)or $telnet_er
+r=1 ;

        if ($telnet_err){                
            print "Unable to telnet to $host machine\n";}

        $telnet -> login(root,siemens) or $login_err=1;
        
    if ($telnet->cmd("uname") == "Linux")
    {
        print OUT "\n<===========================>\n";
        print OUT "\nWELCOME. You have Logged in to $x\n";
        print OUT "\n----------------\n";        
        print OUT "Current Date:  ";
        print OUT $telnet->cmd("date| tail -1"); 
        print OUT "\n----------------\n";        
        print OUT "Serial Number of the Machine is: ";
        print OUT $telnet->cmd("dmidecode -t system | grep Serial");
        print OUT "\n----------------\n";        
        print OUT "Operating System of the Machine is: ";
            print OUT $telnet->cmd("uname | tail -1");
        print OUT "\n----------------\n";         
        print OUT "Host Name of the Machine is";
            print OUT $telnet->cmd("hostname| tail -1");
        print OUT "\n----------------\n";        
        print OUT " Disk Information of the Machine is";
            print OUT $telnet->cmd("df -kh");
        print OUT "\n-----------\n";
        print OUT "IP Address of the Interfaces are : \n";
        print OUT $telnet->cmd("/sbin/ifconfig -a | grep inet| cut -d\
+" \" -f2");
        print OUT "\n-----------\n";
        print OUT "MAC Address of the INterfaces are:\n";
        print OUT $telnet->cmd("/sbin/ifconfig -a | grep ether"); 
    }
[download]

Comment on Telnet Script exits if any of the machine is un-accessible Download Code

Replies are listed 'Best First'.
Re: Telnet Script exits if any of the machine is un-accessible by dasgar (Priest) on Jul 18, 2011 at 16:01 UTC
I think you'll want to change the errmode to be `return`. By default, the errmode is set to `die`. Basically, change you connection line to be something like: `$telnet = Net::Telnet->new(Host =>"$x",timeout=>13,errmode=>return);` [download] Then you'll need to check `$telnet` to determine if it was able to successfully connect or not. Check the documentation of Net::Telnet for more details on this.	[reply] [d/l] [select]
Re^2: Telnet Script exits if any of the machine is un-accessible by Anonymous Monk on May 30, 2012 at 13:31 UTC
You can user nmap instead of all these things.It would be better for you. nmap -p9090 172.16.177.103 \| grep 9090 \| awk '{print $2}' .This is an Example for that	[reply]
Re: Telnet Script exits if any of the machine is un-accessible by kennethk (Abbot) on Jul 18, 2011 at 15:54 UTC
Does your script give you any debugging information when is exits? I suspect it is as simple as you are not handling the error conditions properly, as described in Net::Telnet (look for `errmode`). You could probably fix this simply with a next: `if ($telnet_err){ print "Unable to telnet to $host machine\n"; next; }` [download]	[reply] [d/l] [select]
Re: Telnet Script exits if any of the machine is un-accessible by flexvault (Monsignor) on Jul 18, 2011 at 15:55 UTC
$telnet -> login($account,$password) or $login_err=1; I hope your login is not a real account and password. Please change it to something else immediately! You're in a windows environment, so others on this list are better prepared to answer your real problem. But from a security perspective, just the hint that this account/password is real, will start a run on servers around the world! Good Luck! "Well done is better than well said." - Benjamin Franklin	[reply]