in reply to Automatic IP address Generation

The dotted form of IP addresses is just a representation of a 32-bit number. You'll have better luck working with an IP address as a number. 
use Socket qw( inet_aton inet_ntoa );

sub fr_dotted { unpack 'N', inet_aton @_ ? $_[0] : $_ }
sub to_dotted { inet_ntoa pack 'N', @_ ? $_[0] : $_ }

my $next = fr_dotted('100.1.3.41');
my $max  = fr_dotted('100.1.3.50');

die if $next > $max;
my $new = $next++;

print(to_dotted($new), "\n");

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Update: Had inet_aton where inet_ntoa should have been used.

Replies are listed 'Best First'.
Re^2: Automatic IP address Generation
by ajd335 (Novice) on Jul 30, 2008 at 15:59 UTC
    Hi Ikegami, Thanks for your help. My result.txt file contains data like 
    host1-001 10.22.33.22
host2-001 10.33.68.254

    [download]
    something like above , And as i told you before I want to have update that with 
    host1-001 10.1.3.41
host2-001 10.1.3.42

    [download]
    so in your above code , where should i give the result.txt( which contains old IP as argument)...I really dont have idea. Thanks,
[reply]
[d/l]
[select]
Re^2: Automatic IP address Generation
by ajd335 (Novice) on Jul 30, 2008 at 19:42 UTC
    Hi Ikegami , I have tried out the below. 
     #!/usr/bin/perl
open(HANDLE , "result3.txt") || die("Could not open file!");
while(<HANDLE>)
{
chomp;
use Socket qw( inet_aton inet_ntoa );

sub fr_dotted { unpack  'N', inet_aton @_ ? $_[0] : $_ }
sub to_dotted { inet_aton  pack  'N', @_ ? $_[0] : $_ }

my $next = fr_dotted('100.1.3.41');
my $max  = fr_dotted('100.1.3.50');

die if $next > $max;
my $new = $next++;
$new1 = to_dotted($new);
print $new1;
}
close(HANDLE);

    [download]
    But that does not give me the desired results. Am I doing it correct ?
[reply]
[d/l]
      #!/usr/bin/perl

use strict;
use warnings;

use Socket qw( inet_aton inet_ntoa );

sub fr_dotted { unpack 'N', inet_aton @_ ? $_[0] : $_ }
sub to_dotted { inet_ntoa pack 'N', @_ ? $_[0] : $_ }


my $next = fr_dotted('100.1.3.41');
my $max  = fr_dotted('100.1.3.50');

while (<>) {
   chomp;
   my ($host) = split(' ');
   
   die("Exceed max\n") if $next > $max;
   my $addr = $next++;

   print($host, ' ', to_dotted($addr), "\n");
}

      [download]
      renum.pl infile > outfile

  -or-

perl -i.bak renum.pl file

      [download]

      Untested.

[reply]
[d/l]
[select]
        Hi ikegami, I have removed the blank space part. But , One more thing , I also need to check if the IP is already assigned someone or not..If it is assigned to some workstation , then that IP add should be skipped and the next available IP address should be taken. Thanks,
[reply]
        Hi Ikegami , Yes it gives me answer . But the thing is it is also taking the white spaces and also assign them the IP address. i mean it also take the blank lines into consideration
[reply]

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