perldoc -f open has examples. Basically you duplicate STDOUT and STDERR to other filehandles before closing them. Then you duplicate the saved filehandles back to STDOUT and STDERR. 
        print "STDOUT #1\n";warn "STDERR #1\n";
open my $savestdout, '>&', \*STDOUT;
        print "STDOUT #2\n";warn "STDERR #2\n";
open my $savestderr, '>&', \*STDERR;
        print "STDOUT #3\n";warn "STDERR #3\n";
close STDOUT;
        print "STDOUT #4\n";warn "STDERR #4\n";
close STDERR;
        print "STDOUT #5\n";warn "STDERR #5\n";
open STDOUT, '>&', $savestdout;
        print "STDOUT #6\n";warn "STDERR #6\n";
open STDERR, '>&', $savestderr;
        print "STDOUT #7\n";warn "STDERR #7\n";
close $savestdout;
        print "STDOUT #8\n";warn "STDERR #8\n";
close $savestderr;
        print "STDOUT #9\n";warn "STDERR #9\n";

[download]
OK, this is bizarre. When I re-open STDOUT, I get output from warn even though STDERR is still closed. perldoc -f warn doesn't describe this behavior.

In reply to Re^3: J.A.P.H. with intentional eval failure by jdalbec
in thread J.A.P.H. with intentional eval failure by ktross

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.