Something weird is happening when I'm starting a Perl script under powershell and redirecting STDOUT to a logfile

PS D:\tmp> perl -E"$|=1;print $]" >.\tmp.log                    # writ
+es log immediately 
PS D:\tmp> cat .\tmp.log
5.032001
PS D:\tmp> perl -E"$|=1;print $];sleep 100" >.\tmp.log          # does
+n't write log 
Terminating on signal SIGINT(2)
PS D:\tmp> cat .\tmp.log                                        # empt
+y
PS D:\tmp> exit

d:\tmp>perl -E"$|=1;print $];sleep 100" >.\tmp.log              # writ
+es log immediately
Terminating on signal SIGINT(2)

d:\tmp> type .\tmp.log
5.032001
[download]

What am I missing? Is this a bug in Perl or Powershell?

update

Couldn't reproduce the even after finishing sleep part anymore

update

OK to make sure that it's not a side effect from -E I created a (very) short script.pl

PS D:\tmp> echo '$|=1;print $];sleep 10' > tst.pl
PS D:\tmp> cat .\tst.pl
$|=1;print $];sleep 10
PS D:\tmp> perl tst.pl                 # prints immediately
5.032001
PS D:\tmp> perl tst.pl >tmp.log
Terminating on signal SIGINT(2)
PS D:\tmp> cat .\tmp.log
PS D:\tmp>
PS D:\tmp> perl tst.pl >tmp.log        # don't CTRL-c, just wait
PS D:\tmp> cat .\tmp.log
5.032001
[download]

again,

if I run the script without redirection I see the output immediately

if I redirect, the log isn't written while sleeping

if I terminate with CTRL c the log isn't written either

only if I wait 10 sec I'll see the log written

---

In reply to (WIN) Autoflush, Perl, Sleep and Powershell by LanX

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.