Unexpected Output

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

Hi Monks

I want to validate a port number in UNIX box. The program gets input from the user until the value is free port.
I expect the program finally give one free port number at variable '$free_port'.

But the program returns the correct free port value at first time. And returns '$freeport = 1' in number of times prompt from the user.
Please have a look in to the below output's, program, Note and give your suggestions.
Thanks

Program Output :

Please Enter the Port Number ( Default 10001 ) :
Port 10001 is currently used by another application
Please try again

Please Enter the Port Number ( Default 10001 ) : 99
Port 99 is currently used by another application
Please try again

Please Enter the Port Number ( Default 10001 ) : 111

Port 111 connected successfully

Free port is : 111
Free port is : 1
Free port is : 1

Expected Output:

Program :

use strict;
use warnings;
use IO::Socket;

## Some Main Stuffs Here

## Get port numbers
&get_input();

## Few Remaing stuffs Here

sub get_input
{
        my $default_port = "10001";
        print "\nPlease Enter the Port Number  [ Default $default_port
+ ] : ";
        chomp(my $get_port_no=<>);
        $get_port_no=($get_port_no)?$get_port_no : $default_port;
        my $free_port = check_port($get_port_no);
        print "\nFree port is : $free_port\n";
}

## Validate the prompted port number
sub check_port
{
        my ($port)=@_;
        my $host='127.0.0.1';

        my $socket = new IO::Socket::INET(PeerAddr => $host.":".$port,
+ Timeout => 5);

        if ($socket) {
                print "\nPort $port connected successully\n";
                return $port;
        }
        else {
                print "Port $port is currently used by another applica
+tion\nPlease try again\n";
                &get_input();
        }
}
[download]

Note :
'netstat -an | grep LISTEN' command gives the free port number list in UNIX box.

Comment on Unexpected Output - 2 Download Code

Replies are listed 'Best First'.
Re: Unexpected Output - 2 by kcott (Archbishop) on Nov 08, 2010 at 07:11 UTC
Your code is recursive. Perhaps you want something like this sort of pseudo-code: `while (not $connected) { get_input(); check_port(); if ($good_port) { $connected = 1; } }` [download] -- Ken	[reply] [d/l]
Re^2: Unexpected Output - 2 by k_manimuthu (Monk) on Nov 08, 2010 at 12:34 UTC
Thanks kcott. Based on your pseudo - code. I modify the code's. Now it working fine, what i expect Thanks a lot	[reply]


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Unexpected Output - 2