Please consider adding some code tags in your post, so your data looks more like data.

Note that your first example uses DBD::CSV, which uses Text::CSV_XS underneath to parse the CSV data. Example 2 uses <FINAL> plus invalid split. Examples 3 uses the same reading mechanism as example 2, but with a split that is still unsafe and example 4 uses two endless loops.

If you want to do the "work" yourself and not rely on DBD::CSV, switch to using one of the two proved CSV parsers: Text::CSV (as ig already suggested) or Text::CSV_XS (the fast one).

In what you describe, getline_hr might be very helpful, maybe even getline_hr_all.

use text::CSV_XS;

my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, allow_whit
+espace => 1 });

open my $fh, "<", "final2.csv" or die "final2.csv: $!";
$csv->column_names ($csv->getline ($fh)); # Read the header line
while (my $r = $csv->getline_hr ($fh)) {
    $File1Map{$r->{username}} = $r->{date_modified};
    }

:
:
$csv->eol ("\n"); # Now use it for output

# inside the for/while loop
    $csv->print ($fh, [ $usename, $oldvalue, $newvalue ]);

[download]

Enjoy, Have FUN! H.Merijn

In reply to Re: Merging Two CSV files Based on Two Columns by Tux
in thread Merging Two CSV files Based on Two Columns by TheCanadian

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