Amend perl script so that words are matched on a word for word basis - text-processing

Question

I have been using this perl script (thanks to Jeff Schaller) to match 3 or more words in the title fields of two separate csv files.
Original question here:
https://unix.stackexchange.com/questions/283942/matching-3-or-more-words-from-fields-in-separate-csv-files?noredirect=1#comment494461_283942
I have also added some exception functionality following advice from meuh:
#!/bin/perl
my #csv2 = ();
open CSV2, "<csv2" or die;
#csv2=<CSV2>;
close CSV2;
my %csv2hash = ();
for (#csv2) {
chomp;
my ($title) = $_ =~ /^.+?,\s*([^,]+?),/; #/ match the title
$csv2hash{$_} = $title;
}
open CSV1, "<csv1" or die;
while (<CSV1>) {
chomp;
my ($title) = $_ =~ /^.+?,\s*([^,]+?),/; #/ match the title
my #titlewords = split /\s+/, $title; #/ get words
my #new; #add exception words which shouldn't be matched
foreach my $t (#titlewords){
push(#new, $t) if $t !~ /^(and|if|where)$/i;
}
#titlewords = #new;
my $desired = 3;
my $matched = 0;
foreach my $csv2 (keys %csv2hash) {
my $count = 0;
my $value = $csv2hash{$csv2};
foreach my $word (#titlewords) {
++$count if $value =~ /\b$word\b/i;
last if $count >= $desired;
}
if ($count >= $desired) {
print "$csv2\n";
++$matched;
}
}
print "$_\n" if $matched;
}
close CSV1;
During my testing, one issue I've found that I would like to tweak is that if csv2 contains a single common word such as the, if this is replicated in csv1 three or more times then three positive matches is found. To clarify:
If csv1 contains:
1216454,the important people feel the same way as the others, 15445454, 45445645
^ i.e. there are three insatnces of the in the above line
If csv2 contains:
14564564,the tallest man on earth,546456,47878787
^ i.e. there is one instance of the in this line
Then I would like only one word to be classed as matching, and there be no output (based on my desired number of matching words- 3 ) because there is only one instance of the matching word in one of the files.
However if:
csv1 contained:
1216454,the important people feel the same way as the others,15445454, 45445645
and csv2 contained:
15456456,the only way the man can sing the blues,444545,454545
Then, as there are three matching words in each (i.e. 3 instances of the word the in each title, then I would like this to be classed as a matching title based on my desired number of matching words being 3 or more, thus generating the output:
1216454,the important people feel the same way as the others,15445454, 45445645
15456456,the only way the man can sing the blues,444545,454545
I would like to amend the script so that if there is one instance of a word in a csv, and multiple instances of the same word in the other csv then that is classed as only one match. However, if there were say 3 instance of the word the in both files, then it should still be classed as three matches. Basically I would like matches to be on a word for word basis.
Everything about the script other than this is perfect so I would rather not go back to the drawing board completely as I am happy with everything other than this.
I hope I've explained it ok, if anyone need any clarification let me know.

Answer 1

If you just wan to count unique matches, you can use a hash instead of a list to collect the words from csv1, just like you do for csv2, and then also count the occurrences of each word separately:
#!/usr/bin/env perl
my #csv2 = ();
open CSV2, "<csv2" or die;
#csv2=<CSV2>;
close CSV2;
my %csv2hash = ();
for (#csv2) {
chomp;
my ($title) = $_ =~ /^.+?,\s*([^,]+?),/; #/ match the title
$csv2hash{$_} = $title;
}
open CSV1, "<csv1" or die;
while (<CSV1>) {
chomp;
my ($title) = $_ =~ /^.+?,\s*([^,]+?),/; #/ match the title
my %words;
$words{$_}++ for split /\s+/, $title; #/ get words
## Collect unique words
my #titlewords = keys(%words);
my #new; #add exception words which shouldn't be matched
foreach my $t (#titlewords){
push(#new, $t) if $t !~ /^(and|if|where)$/i;
}
#titlewords = #new;
my $desired = 3;
my $matched = 0;
foreach my $csv2 (keys %csv2hash) {
my $count = 0;
my $value = $csv2hash{$csv2};
foreach my $word (#titlewords) {
my #matches = ( $value=~/\b$word\b/ig );
my $numIncsv2 = scalar(#matches);
#matches = ( $title=~/\b$word\b/ig );
my $numIncsv1 = scalar(#matches);
++$count if $value =~ /\b$word\b/i;
if ($count >= $desired || ($numIncsv1 >= $desired && $numIncsv2 >= $desired)) {
$count = $desired+1;
last;
}
}
if ($count >= $desired) {
print "$csv2\n";
++$matched;
}
}
print "$_\n" if $matched;
}
close CSV1;