I don't understand the point that you are trying to make. You open a file handle to a Perl var. That's fine. You set binmode before you read from that file handle and that's fine too.

Find some .jpg file you have somewhere and try the code that I posted. Use of the DATA file handle is "special".

Your initial premise that you could read binary data from the DATA file handle is wrong. That data will be in a character format.

Update: Here is a Perl program that reads and prints itself. DATA is an already read and opened file handle. 

use warnings;
use strict;

print "testing seek of DATA handle\n";
print "this will print this program\n";
seek (DATA,0,0); 
my $text = do{ local $/ = undef; <DATA>; };
print $text;


__DATA__
asdfasdf asdfasdf

[download]

In reply to Re^5: Error binmode() on unopened filehandle by Marshall
in thread Error binmode() on unopened filehandle by RedJeep

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.