Please help me understand this code...

[NOTSomebody]

I am new to Perl and I have these codes but I am not quite understand the regular expression here. Can any1 please explain to me?

$csv = "test.csv";
open(DAT, $csv) || die("Cannot Open File");

while (<DAT>) {
    my @new  = ();

    push(@new, $+) while $_ =~ m{          #what does these means
        "([^\"\\]*(?:\\.[^\"\\]*)*)",?
           |  ([^,]+),?
           | ,
		}gx;

    push(@new, undef) if substr($_, -1,1) eq ',';
	   
	my $string = format_string(@new);
	my $query = qq{Insert into person_info VALUES ($string)};
    print $query, "\n"; 
}  

 sub format_string {  
		my $string; 
        foreach (@_) {
            if  (/[^\d]/) {          #what does these mean
                $string .= qq{"$_",};
			} else {
				$string .= qq{$_,};
			}
		}
		return substr($string, 0, -1); 
	}

[KevinADC]

See your thread on Devshed.