Match column in 2 CSV files and display output in third file - perl

Question

I have 2 CSV files, file1.csv and file2.csv . I have to pick each row of column 3 in file1 and iterate through column 3 of file2 to find a match and if the match occurs then display the complete matched rows(from column 1,2 and 3)only from file2.csv in a third csv file.My code till now only fetches the column 3 from both the csv files. How can I match column 3 of both the files and display the matched rows ? Please help.
File1:
Comp_Name,Date,Files
Component1,2013/04/01,/Com/src/folder1/folder2/newfile.txt;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile24;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile25;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile26;
Component1,2013/04/25,/Com/src2;
File2:
Comp_name,Date,Files
Component1,2013/04/07,/Com/src/folder1/folder2/newfile.txt;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile24;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile25;
Component2,2013/04/23,/Com/src/folder1/folder2/newfile.txt;
Component3,2013/04/27,/Com/src/folder1/folder2/testfile24;
Component1,2013/04/25,/Com/src2;
Output format:
Comp_Name,Date,Files
Component1,2013/04/07,/Com/src/folder1/folder2/newfile.txt;
Component2,2013/04/23,/Com/src/folder1/folder2/newfile.txt;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile24;
Component3,2013/04/27,/Com/src/folder1/folder2/testfile24;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile25;
Component1,2013/04/25,/Com/src2;
Code:
use strict;
use warnings;
my $file1 = "C:\\pick\\file1.csv";
my $file2 = "C:\\pick\\file2.csv";
my $file3 = "C:\\pick\\file3.csv";
my $type;
my $type1;
my #fields;
my #fields2;
open(my $fh, '<:encoding(UTF-8)', $file1) or die "Could not open file '$file1' $!"; #Throw error if file doesn't open
while (my $row = <$fh>) # reading each row till end of file
{
chomp $row;
#fields = split ",",$row;
$type = $fields[2];
print"\n$type";
}
open(my $fh2, '<:encoding(UTF-8)', $file2) or die "Could not open file '$file2' $!"; #Throw error if file doesn't open
while (my $row2 = <$fh2>) # reading each row till end of file
{
chomp $row2;
#fields2 = split ",",$row2;
$type1 = $fields2[2];
print"\n$type1";
foreach($type)
{
if ($type eq $type1)
{
print $row2;
}
}
}

Answer 1

This is not a matter to over complicate.. I would personally use a module Text::CSV_XS or as mentioned already Tie::Array::CSV to perform here.
If you're having trouble using a module, I suppose this would be an alternative. You can modify to your desired wants and needs, I used the data you supplied and got the results you want.
use strict;
use warnings;
open my $fh1, '<', 'file1.csv' or die "failed open: $!";
open my $fh2, '<', 'file2.csv' or die "failed open: $!";
open my $out, '>', 'file3.csv' or die "failed open: $!";
my %hash1 = map { $_ => 1 } <$fh1>;
my %hash2 = map { $_ => 1 } <$fh2>;
close $fh1;
close $fh2;
my #result =
map { join ',', $hash1{$_->[2]} ? () : $_->[0], $_->[1], $_->[2] }
sort { $a->[1] <=> $b->[1] || $a->[2] cmp $b->[2] || $a->[0] cmp $b->[0] }
map { s/\s*$//; [split /,/] } keys %hash2;
print $out "$_\n" for #result;
close $out;
__OUTPUT__
Comp_name,Date,Files
Component1,2013/04/07,/Com/src/folder1/folder2/newfile.txt;
Component2,2013/04/23,/Com/src/folder1/folder2/newfile.txt;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile24;
Component3,2013/04/27,/Com/src/folder1/folder2/testfile24;
Component1,2013/04/24,/Com/src/folder1/folder2/testfile25;
Component1,2013/04/25,/Com/src2;

Answer 2

This is a job for a hash ( my %file1)
so instead of continually opening the files you can read the contents into hashes
#fields = split ",",$row;
$type = $fields[2];
$hash1{$type} = $row;
I see you have duplicates too so the hash entry will be replaced upon duplication
so you can store an array of values in the hash
$hash1{$type} = [] unless $hash1{$type};
push #{$hash1{$type}}, $row;
Your next problem is how to traverse the arrays inside hashes

Answer 3

Here is an example using my Tie::Array::CSV module. It uses some clever Perl tricks to represent each CSV file as a Perl array of arrayrefs. I use it to make an index of the first file, then to loop over the second file and finally to output to the third.
#!/usr/bin/env perl
use strict;
use warnings;
use Tie::Array::CSV;
tie my #file1, 'Tie::Array::CSV', 'file1' or die 'Cannot tie file1';
tie my #file2, 'Tie::Array::CSV', 'file2' or die 'Cannot tie file2';
tie my #output, 'Tie::Array::CSV', 'output' or die 'Cannot tie output';
# setup a match table from file2
my %match = map { ( $_->[-1] => 1 ) } #file1[1..$#file1];
#header
push #output, $file2[0];
# iterate over file2
for my $row ( #file2[1..$#file2] ) {
next unless $match{$row->[-1]}; # check for match
push #output, $row; # print to output if match
}
The output I get is different from yours, but I cannot figure out why your output does not include testfile25 and src2.