my file contains multiple ipconfig outputs.

Ah, that changes things a bit. Is there a distinct and consistent string pattern that separates one ipconfig output from another, such as a blank line, or a line of dashes?

If so, you can assign that string to "$/" (rather than leaving it with the default value of CRLF, or setting it to undef, as suggested by BrowserUK). This way, you read one whole ipconfig output set in a single iteration of while (<>). For example, if the successive records are separated by a single blank line (and blank lines never occur within a single ipconfig output record), then you could do like this (untested): 

my %hostdata;
{
   $/ = "\x0d\x0a\x0d\x0a";  # record separator is now a blank line

   while (<>) {   # $_ now contains one whole ipconfig output
      next unless ( /Host Name.*?:\s*(.*)/ );
      my $host = $1;
      @{$hostdata{$host}{dns}} = ( /\s(\d+\.\d+\.\d+\.\d+)\s/g );
      ( $hostdata{$host}{typ} ) = ( /Node Type.*?:\s*(.*)/ );
   }
}

# Now, keys %hostdata gives the list of host names from
# all the ipconfig runs, and $hostdata{"hostname"} contains 
# the dns and node type info for each host.

for ( sort keys %hostdata ) {
   print join "\n", $_, @{$hostdata{$_}{dns}}, $hostdata{$_}{typ}, "\n
+";
}

[download]
(update: removed a spurious line of code)

If the separation between ipconfig runs is not distinct or consistent, then you'll want to fall back on BrowserUK's less-favored method that reads one line at a time and uses a status flag to keep track of what it's supposed to look for (and what it's supposed to do) as it works through each multi-line record.

In reply to Re: Re: Re: Re: Re: reading lines by graff
in thread reading lines by spill

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