The first three arguments of open3 are outputs. open3 creates pipes and assigns them to the provided variables (causing the handle they previously held to be closed).

That is unless they hold a string that starts with "<&" (1st arg) or ">&" (2nd and 3rd args). When these are used, open3 use the specified handle instead of creating a pipe. Like in the example that worked, you need to use "<&" to tell open3 to use an existing handle. 

open3( '<&'.fileno($new_sock), ... )

[download]

There is also a special meaning for the third arg when it's undef, but it's unrelated to the issue at hand.

Update: Added explanation.

In reply to Re: IPC::Open3 not connecting network socket handle by ikegami
in thread IPC::Open3 not connecting network socket handle by Anonymous Monk

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.