Re^3: Parsing multiple lines based on a given String

There are a number of ways to implement this code.
One is shown below.
Basically, keep track of the last hostname found. When you find a valid ip, and that ip is the one that you are looking for, then that goes with the most previous hostname.

#!usr/bin/perl
use warnings;
use strict;


my $file =<<END;
object-group network HOSTNAME_1ST
 network-object host 10.1.1.1
 
object-group network HOSTNAME_2nd
 network-object host 10.3.1.1
 
object-group service WEB_TCP tcp
 port-object eq 80
END

my $hostname;

open my $fh, '<', \$file or die "unable to open read file $!";
while (my $line = <$fh>)
{
  if (my ($name) = $line =~ /^object-group network (\w+)/)
  {
     $hostname = $name; # "last seen hostname"
  }
  
  my ($ip) = $line =~ /(\d+\.\d+\.\d+\.\d+)/;
  
  if (defined ($ip) and $ip eq '10.3.1.1')
  {
     print "ip $ip goes with host name $hostname\n";  
  }
}
__END__
ip 10.3.1.1 goes with host name HOSTNAME_2nd
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Comment on Re^3: Parsing multiple lines based on a given String Download Code

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Re^4: Parsing multiple lines based on a given String by ArifS (Beadle) on Jun 27, 2016 at 15:23 UTC
I tried to replace the following line- `open my $fh, '<', \$file or die "unable to open read file $!";` [download] with - `my $filename = 'file.txt'; open(my $fh, '<:encoding(UTF-8)', $filename) or die "Could not open file '$filename' $!";` [download] and it doesn't give an output or any error. Any clue? --------------------------------------------------------------- oh, never mind... had to use chomp. chomp($line);	[reply] [d/l] [select]

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Re^4: Parsing multiple lines based on a given String
by ArifS (Beadle) on Jun 27, 2016 at 15:23 UTC

open my $fh, '<', \$file or die "unable to open read file $!";
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my $filename = 'file.txt';
open(my $fh, '<:encoding(UTF-8)', $filename)
  or die "Could not open file '$filename' $!";
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[reply]
[d/l]
[select]