Hi, I am trying to access the serial port through perl script, for that i am using the SerialPort.pm and ComPort.pm module. In serialPort.pm module there is a subroutine called "new". I would like to understand the exact working of the new subroutine. Some portion of the new subroutine is as follows 
sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $device = shift;
    my $alias = $device;
    if ($device =~ /^COM\d+$/io) {
    $device = '\\\\.\\' . $device;
    # required COM10 and beyond, done for all to facilitate testing
    }
    my @new_cmd = ($device);
    my $quiet = shift;
    if ($quiet) {
        push @new_cmd, 1;
    }
    my $self  = $class->SUPER::new(@new_cmd);

    unless ($self) {
        return 0 if ($quiet);
        return;
    }

[download]

In reply to Working of new subroutine by vrushali

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.