Unfortunately too much of your example is either commented out or are variables which we cannot tell how you have set. An SSCCE would be preferable. Here's one showing how it works:

#!/usr/bin/env perl 
use strict;
use warnings;

my $command = 'echo foo';
my $stdout = `$command`;
print "STDOUT: $stdout";

$command = 'ls some-missing-file';
my $stderr = `$command 2>&1 >/dev/null`;
print "STDERR: $stderr";

print "\nNow display stdout while command runs:\n";
$command = 'echo bar;sleep 3; echo baz';
open my $pipe, "($command) |";
while (<$pipe>) { print; }
close $pipe

[download]

Caveat: only tested on Linux. Differences on Win32 are O/S related and not something I can help you with.

In reply to Re: Caturing 7zip output with Perl by hippo
in thread Caturing 7zip output with Perl 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.