The diamond always works on the files in @ARGV. It also provides another level of magic, if @ARGV is empty, it reads STDIN. This is a very common idiom for writing filter programs.

Another useful trick is to realize that @ARGV starts out with the command line parameters, but it is just a variable. You can change it. (For example, remove some flags or commands and then process the rest, or use the parameters to construct a list of filenames that replaces @ARGV before processing.

The last trick is not one to be used lightly, because it's likely to confuse some people. But, sometimes it is exactly the tool you need.

G. Wade

In reply to Re^3: A Tribute To The Monks Of Wisdom by gwadej
in thread A Tribute To The Monks Of Wisdom by koolgirl

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.