One idea would be to make a snapshot of %INC when compile time ends. If an entry is in the snapshot, the module was use()d, otherwise it was require()d.

For instance: 

CHECK {
    my %snap = %INC;

    sub report {
        for ( keys %INC ) {
            my $ans = $snap{ $_} ? 'use()d' : 'require()d';
            print "$_ was $ans\n";
        }
    }
}

[download]
Here, report() simply prints a list with each module's status. A more elaborate version could return the status of a module that is passed in.

Of course, %INC can be manipulated in every which way, so the method isn't fool-proof. It makes up for that with simplicity.

Update:
Another possible drawback of this approach is that the module that implements it must itself be use()d and can't be loaded at run time. (It would be too late to run the CHECK block.) That may be true for other solutions also.

Anno

In reply to Re: Was a module use'd or require'd? by Anno
in thread Was a module use'd or require'd? by Ovid

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.