Maybe you want to split up the file into several files, then compare the differences between the several files? Along the way, you might find a way how to avoid the "split into several files" part and compare the differences from the same file. I'm not sure where you are having problems, so maybe if you show some code we can help you further.

One possible approach would be to use "paragraph mode" to read in the sections of your file, then split those sections into lines, then find the differences between the sections. Maybe you could use Algorithm::Diff to give you a human readable overview of what changed.

The only reason I would prefer not to split it up into different files is because there would then be 196 files * the 6 different logs that I have.

I have uploaded my code to my scratchpad, but obviously it doesn't work, that's why I'm here. I'm a complete beginner with Perl (and coding in general, I only started in the last week), so please don't laugh at my effort, haha. Also I hope the formatting is OK since I'm new to that too!

Why don't you post your code here instead?

Instead of manually splitting up your source file, you could write a program to split up your source file and then compare the split up parts. You could also skip the part where you write out your input file into separate files and compare the split up parts in memory instead of writing them out to files and reading them back in.

So far, I get the impression that you have not really put much thought into possible approaches. Maybe you shouldn't attack the problem as a whole, but instead simplify the problem first:

• If you have two files, how do you determine their differences?
• If you have one file with two sets of routes, how can you read that file into two memory structures?
• If you have one file with more than two sets of routes, how will you determine the differences?

I have uploaded my code to my scratchpad, but obviously it doesn't work, that's why I'm here.

You mean this code?:

#!/usr/bin/perl -w

use strict;

my $infile = 'JPStream.csv';
my $outfile = 'new1.csv';

open IN, "< $infile" or die "Can't open $infile : $!";
open OUT, "> $outfile" or die "Can't open $outfile : $!";

my %seen;
my %seen2;
 
while (<IN>) {
     next if /^$/;
     chomp;
       if ( ! $seen2{$_} ) {
       print OUT "$_ Not in the last Traceroute ^\n";
       }
     last if /^$/;
     $seen{$_}++;
     %seen2 = ();
}

while (<IN>) {
     next if /^$/;
     chomp;
       if ( ! $seen{$_} ) {
       print OUT "$_ Not in the last Traceroute^^\n";
       }
     last if /^$/;
     $seen2{$_}++;
     %seen = ();
}
}
[download]

Why not post your code in the same node as your question? It certainly isn't due to length.

Please make it easier for us to help you help yourself.

HTH,

planetscape

I understand, that you need a hop- and section-wise comparison, so the following might get you started. However, the naive - text based - approach below will fail when the order of hops/IP's changes - e.g. by means of topology changes or selection of an alternative route having more/less intermediate hops. IF that is also of concern to you, a real network model (nodes and edges (graphs)) would be better suited than a plain text comparison. HTH

                          IP#1    IP#2/2b   IP#3     IP#4   Section  D
+iff
                          ============================================
+==================
OK   (alternate route):   HOP1 --- HOP2  ----------- HOP3   (#1)
                          HOP1 --- HOP2b ----------- HOP3   (#2)  --> 
+@hop2: IP#2-->IP#2b

EEK! (non-equidistant):   HOP1 --- HOP2  ----------- HOP3   (#1)
     a) shorter route     HOP1 --------------------- HOP2   (#2a) --> 
+@hop2: IP#2-->IP#4 (err?)
     b) longer  route     HOP1 --- HOP2 --- HOP3 --- HOP4   (#2b) --> 
+@hop3: IP#4-->IP#3 (err?)
[download]

use strict;
use warnings;

sub prettyip {
  my $ip = shift;
  $ip =~ s/ (\d+) / sprintf("%03d",$1) /smgex;
  return $ip;
}

my %last_seen_ip_from_hop;   # last IP seen for key=HOP
my $section      = 1;        # section within the file
my $previous_hop = 0;        # previous HOP / new section event

while (my $line = <DATA>) {
  if ($line =~ /^(\d+),(\S+)/) { # extract HOP and IP
    my ($hop, $ip)    = ($1, $2);
    my $last_ip_seen  = $last_seen_ip_from_hop{$hop};
    my ($changemark_pre, $changemark_pos)  = ("", "");

    # detect a new section (A/B/C)
    $section++, print "\n" if $previous_hop > $hop; # new file/section
    $previous_hop = $hop;

    # notify if a change occured for a given hop since last seen
    if (defined $last_ip_seen and $ip ne $last_ip_seen) {
      $changemark_pre = 'changed to';
      $changemark_pos = '(was: ' . prettyip($last_ip_seen) . ')';
    }
    $last_seen_ip_from_hop{$hop} = $ip; # init or update current HOP/I
+P

    printf "sect.%2d / hop %2d: %15s %15s %s\n",
      $section, $hop, $changemark_pre, prettyip($ip), $changemark_pos;
  }
}


__DATA__
13,4.69.137.70
14,4.69.134.70
15,4.69.134.113
16,4.69.135.185
17,4.69.134.246
18,4.68.18.75
19,4.59.0.10
20,124.211.34.129
21,203.181.100.61
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11

13,4.69.137.74
14,4.69.134.70
15,4.69.134.113
16,4.69.135.185
17,4.69.134.246
18,4.68.18.11
19,4.59.0.10
20,124.211.34.121
21,203.181.100.61
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11

13,4.69.137.70
14,4.69.134.78
15,4.69.134.125
16,4.69.135.185
17,4.69.134.250
18,4.68.18.139
19,4.59.0.10
20,124.211.34.121
21,203.181.100.189
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11
[download]

sect. 1 / hop 13:                 004.069.137.070
sect. 1 / hop 14:                 004.069.134.070
sect. 1 / hop 15:                 004.069.134.113
sect. 1 / hop 16:                 004.069.135.185
sect. 1 / hop 17:                 004.069.134.246
sect. 1 / hop 18:                 004.068.018.075
sect. 1 / hop 19:                 004.059.000.010
sect. 1 / hop 20:                 124.211.034.129
sect. 1 / hop 21:                 203.181.100.061
sect. 1 / hop 22:                 118.155.197.140
sect. 1 / hop 23:                 124.211.010.066
sect. 1 / hop 24:                 163.139.130.138
sect. 1 / hop 25:                 163.139.124.057
sect. 1 / hop 26:                 202.215.179.001
sect. 1 / hop 27:                 202.215.179.011

sect. 2 / hop 13:      changed to 004.069.137.074 (was: 004.069.137.07
+0)
sect. 2 / hop 14:                 004.069.134.070
sect. 2 / hop 15:                 004.069.134.113
sect. 2 / hop 16:                 004.069.135.185
sect. 2 / hop 17:                 004.069.134.246
sect. 2 / hop 18:      changed to 004.068.018.011 (was: 004.068.018.07
+5)
sect. 2 / hop 19:                 004.059.000.010
sect. 2 / hop 20:      changed to 124.211.034.121 (was: 124.211.034.12
+9)
sect. 2 / hop 21:                 203.181.100.061
sect. 2 / hop 22:                 118.155.197.140
sect. 2 / hop 23:                 124.211.010.066
sect. 2 / hop 24:                 163.139.130.138
sect. 2 / hop 25:                 163.139.124.057
sect. 2 / hop 26:                 202.215.179.001
sect. 2 / hop 27:                 202.215.179.011

sect. 3 / hop 13:      changed to 004.069.137.070 (was: 004.069.137.07
+4)
sect. 3 / hop 14:      changed to 004.069.134.078 (was: 004.069.134.07
+0)
sect. 3 / hop 15:      changed to 004.069.134.125 (was: 004.069.134.11
+3)
sect. 3 / hop 16:                 004.069.135.185
sect. 3 / hop 17:      changed to 004.069.134.250 (was: 004.069.134.24
+6)
sect. 3 / hop 18:      changed to 004.068.018.139 (was: 004.068.018.01
+1)
sect. 3 / hop 19:                 004.059.000.010
sect. 3 / hop 20:                 124.211.034.121
sect. 3 / hop 21:      changed to 203.181.100.189 (was: 203.181.100.06
+1)
sect. 3 / hop 22:                 118.155.197.140
sect. 3 / hop 23:                 124.211.010.066
sect. 3 / hop 24:                 163.139.130.138
sect. 3 / hop 25:                 163.139.124.057
sect. 3 / hop 26:                 202.215.179.001
sect. 3 / hop 27:                 202.215.179.011
[download]

Parse the file into individual route blocks so that you end up with an array (routes) of arrays (nodes in a route). Then use Algorithm::Diff to compare pairs of routes to pull out the difference information you require.

If you'd have shown us your code I'd have shown you mine.

Sorry, I read in the FAQ that it was best to post code in the scratchpad so it was easier for other users to see!

Most of these suggestions are going way over my head, like I said I'm not that well versed with Perl at all!

Scratchpads are transitory. Code is best placed in its relevant thread for the benefit of those who come days, weeks, months after the scratchpad has been altered or cleared.

I think if you carefully re-read the FAQ, it actually suggests posting code on your scratchpad if you have asked (or are about to ask) a longish question in the Chatterbox.

HTH,

planetscape

The following uses Algorithm::Diff to do the heavy lifting:

use strict;
use warnings;
use Algorithm::Diff;

my @routes;

local $/ = "\n\n";

push @routes, $_ while $_ = <DATA>;
chomp @routes;

@routes = map {[split "\n"]} @routes;

my @reference = @{shift @routes};
my $lenChanges = 0;
my $hopChanges = 0;

for my $route (@routes) {
    my @diffs = Algorithm::Diff::diff(\@reference, \@$route);

    next if !@diffs;
    @reference != @$route ? ++$lenChanges : ++$hopChanges;
}

print "Length changes: $lenChanges\n";
print "Hop changes:    $hopChanges\n";

__DATA__
13,4.69.137.70
14,4.69.134.70
15,4.69.134.113
16,4.69.135.185
17,4.69.134.246
18,4.68.18.75
19,4.59.0.10
20,124.211.34.129
21,203.181.100.61
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11

13,4.69.137.74
14,4.69.134.70
15,4.69.134.113
16,4.69.135.185
17,4.69.134.246
18,4.68.18.11
19,4.59.0.10
20,124.211.34.121
21,203.181.100.61
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11

13,4.69.137.70
14,4.69.134.78
15,4.69.134.125
16,4.69.135.185
17,4.69.134.250
18,4.68.18.139
19,4.59.0.10
20,124.211.34.121
21,203.181.100.189
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11

13,4.69.137.74
14,4.69.134.70
15,4.69.134.113
16,4.69.135.185
17,4.69.134.246
18,4.68.18.11
19,4.59.0.10
20,124.211.10.120
20,124.211.26.120
21,203.181.100.61
22,118.155.197.140
23,124.211.10.66
24,163.139.130.138
25,163.139.124.57
26,202.215.179.1
27,202.215.179.11
[download]

Prints:

Length changes: 1
Hop changes:    2
[download]

Note too the use of the $/ record separator special variable to ease the parsing of the file into records.

Just wanted to say that I very much appreciate all of the help that has been given to me in this thread.

The reason I haven't replied is that I don't have the time to look at this project at the moment as I have more urgent work to look at in the mean time! So thanks again!