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.