my %routes;
while (my $line = <>) {
  # Grab the route
  my ($key) = ($line =~ /^(\S+)\s/);
  # Make sure we have an array ref for this key
  $route{$key} ||= [];
  # And add this line
  push @{$route{$key}}, $line;
}

foreach my $value (values %routes) {
  if (@$values > 1) {
    print @$values;
    print "\n"; 
  }
}
[download]

You don't have to make sure of having an array ref. for a particular key, your code $route{$key} ||= [];, as doing the push @{$route{$key}}, $line; will push onto an auto-vivified array ref. if one doesn't exist or push onto the existing ref. otherwise.

Cheers,

JohnGG

Thanks very much. I didn't know that push would auto-vivify in that way. That's going to reduce my line count a bit more in the future.

How are you populating $line from the file? I have tried opening the file then going into the while loop, but it doesnt seem to be reading the lines into the while loop.

We used <>, which reads from the files named on the command line, or STDIN if none were specified on the command line. You could read from any other file handles instead just by specifying it.

open(my $data_fh, '<', $data_file_name)
   or die("Unable to open data file \"$data_file_name\": $!\n");

while (my $line = <$data_fh>) {
.
.
.
[download]

You should replace the word "data" with something more descriptive, at least in the error message.

my %data;
while (<>) {
   my $net = (split ' ')[0];
   push @{$data{$net}}, $_;
}

foreach my $group (values %data) {
   if (@$group > 1) {
      print @$group;
   }
}
[download]

Update: Tested. Added missing if.

perl -ne '/^(\S+)/;if($s{$1}){print$s{$1}unless$S{$s{$1}}++;print}$s{$
+1}=$_' file
[download]

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

Just printing each line 2x

I'll answer both your posts in one:

Please show a sample.
Please show a sample.


Your sample data doesn't contain duplicates. This does:

10.35.15.64/29     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.15.96/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.2.128/25     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.24.192/26    10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.24.48/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.128/25    10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.32/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.48/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.64/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.80/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.26.0/28      10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.32/28     10.133.3.11     OSPF-EXT1     3        if-illnevera
+nswerquestionsagain-10.133.3.11
10.35.26.16/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.26.192/26    10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.26.32/27     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.26.64/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.26.96/27     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.8.128/27     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.8.192/27     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.9.128/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
[download]

If I run my snippet unaltered, I get

10.35.25.32/28     10.133.3.11     OSPF-EXT1     3        if-servermgm
+t.cntx03-servermgmt-10.133.3.11
10.35.25.32/28     10.133.3.11     OSPF-EXT1     3        if-illnevera
+nswerquestionsagain-10.133.3.11
[download]

It outputs pairs: the previous and the current match. So if you have 3 lines starting with the same CIDR notated IP address, you'll get 4 lines back for that match. With 4 lines matching, you get 6 lines: 3 pairs.

<update>

perl -ne '/^(\S+)/;if($S{$1}){print$S{$1}unless$s{$1}++;print}$S{$1}=$
+_' file
[download]

outputs just 4 lines for 4 matches.

</update>

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

That is just spitting out each line 2x.

In addition to the suggetions above, I would also probably try to use Net::Netmask to make sure none of the networks overlap either.

Oddly enough, its ok if the netmasks overlap, we do some of that for failover reasons...for instance, 2 /23's and 1 /24 for the same group of addresses...the "router" this comes from will follow the most specific prefix.