use strict;
use warnings;

use Text::CSV_XS;
my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, eol => "\n" });

open my $fh, "<:encoding(utf-8)", "file.csv" or die "file.csv: $!";
while (my $row = $csv->getline ($fh)) {
    s/,/~z~/g for @$row;
    $csv->print (*STDOUT, $row);
    }