This question deals with what subs get loaded into my namespace and when are they loaded (startup or runtime). Lets use the CPAN module CGI in the example. Look at the two cases below: 
# Case 1
use CGI qw(:cgi);
my $value = param("Name");

[download]
As opposed to doing the following: 
# Case 2
use CGI;
my $q = CGI->new;
my $value = $q->param("Name");

[download]
It is my understanding that Case 1 will load a whole bunch of subs because of the EXPORT tag :cgi. What happens in Case 2? Are only the subs loaded that the handle $q references? When do they get loaded? Is there any documentation that addresses this area? I think this has to do with Autloader and SelfLoader but I am fuzzy on the things I have read about these topics.

In reply to What gets loaded by SoccerRocks

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.