Hello dracos

ok, I am having issues with the following code STDERR seems to be ending up in the STDOUT handle on the open3

In the first paragraph of the Documentation for IPC::open3 http://perldoc.perl.org/IPC/Open3.html the behaviour you are describing as a problem is outlined.

DESCRIPTION

Extremely similar to open2(), open3() spawns the given $cmd and connects CHLD_OUT for reading from the child, CHLD_IN for writing to the child, and CHLD_ERR for errors. If CHLD_ERR is false, or the same file descriptor as CHLD_OUT, then STDOUT and STDERR of the child are on the same filehandle (this means that an autovivified lexical cannot be used for the STDERR filehandle, see SYNOPSIS). The CHLD_IN will have autoflush turned on.

Your $err is uninitialised, so returns false of undef, and the module behaves accordingly.

The SYNOPSIS of how to set the $err variable shows the use of the Symbol module and setting a literal, due to the autovivified lexical rule. You will need to look that up. The Documentation does mention that IPC::Run has better error handling so there is another option.

Hth

In reply to Re: Issues with IPC::Open3 on win32 by Don Coyote
in thread Issues with IPC::Open3 on win32 by dracos

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.