If you don't know anything about the file, you can only be hopeful, at best. In Unix-land, you can run file against the unknown file to get some info:
$ file EDK

[download]

But since you're most likely in Win32-land, with Perl, you can try to Encode::Guess which character encoding was used for the unknown file. And then (fingers crossed), Encode::Repair the file if things were not quite right.

Sure, you can open (as in read its contents) a file without an extension name. The filename just doesn't have an extension to it.

If, by "open", you mean have Windows figure out a program to open C:\EDK, then it'll probably fail. Windows associates programs based on the target filename's extension (and doesn't provide a default for no-extension).

In reply to Re: How to Determine a File's Character Code by repellent
in thread How to Determine a File's Character Code by spickles

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.