pru-mike

I get realy strange behavior of POE::Wheel::FollowTail on Windows.
I need tailing some files on Windows and POE::Wheel::FollowTail is great for that.
It works fine, but if file reduced or recreated my script hanged to infinity loop.
I could not find anything about this problem in web and here is it.

The reason in how perl built-in stat function worked on Windows

Code:

my $filename = $ARGV[0];

open my $filehandle, "<", $filename;

say "handle: ". join ' ', stat $filehandle;

say "   name: ". join ' ', stat $filename;

Result:

c:\>perl stat_test.pl anyfile.txt

handle: 0 0 33206 1 0 0 0 9 1369992444 1369992444 1369992444

  name: 2 0 33206 1 0 0 2 9 1369992444 1369992444 1369992444

I have test it with various version of ActivePerl and Strawberry perl on Windows XP/7, result always same.
Stat function on Windows show different result with filehande and filename in dev and rdev fields (result same on linux!)
(0 for file filehandle and positive number(2 in example) for file by name)

POE::Wheel::FollowTail use stat (with filehandle and filename) to check if file modified or not.
Because result always different POE::Wheel::FollowTail think that file always new and read it again and again.

And workaround is:

BEGIN{

    *CORE::GLOBAL::stat = sub {

        my @s = CORE::stat($_[0]);

        return (1,@s[1..5],1,@s[7..$#s]);

    };

}