The "←[0J" you are seeing is actually, as ikegami said, a mis-renderend escape sequence.  The "←" is what happens when the command window tries to directly print an escape (\e).

It's probably unnecessary to install 'Win32::CONSOLE::ANSI', though, as it's already part of the ActiveState Perl core (at least in the latest 5.8.7 version).  Here's an experiment you can try.  I've changed the escape sequence to the one for clearing the screen, "\e[H\e[J", which is very easy to see when it occurs.  (It also works in Linux and other places where the ANSI escape sequences are honored): 

use strict;
use warnings;

$|++;

print "\e[H\e[J";

print "\nPress <RETURN> to clear the screen: "; <STDIN>;
require Win32::CONSOLE::ANSI;
print "\e[H\e[J";

[download]

The first time time it prints "\e[H\e[J", it doesn't handle it gracefully, and you'll see escape rendered as "←" again:  "←[H←[J".  The second time, though, since you are now using "Win32::CONSOLE::ANSI", the screen will be cleared.

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

In reply to Re: Weird screen output in my AceShell module by liverpole
in thread Weird screen output in my AceShell module by Ace128

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