use strict;
use warnings;
use Text::CSV_XS;

my $csv = Text::CSV_XS->new();      # create a new object
while (<DATA>) {
    my $status  = $csv->parse($_);  # parse a CSV string into fields
    my @columns = $csv->fields();   # get the parsed fields
    my $str = join '|', @columns;
    print "$str\n";
} 

__DATA__
a,b,c
d,e,"f|g"