That's because $| affects only the currently select()ed output filehandle. IO::Pipe appears to subclass IO::Handle so you can just change 
    $pipe->writer();

[download]
to 
    $pipe->writer();
    $pipe->autoflush();

[download]

In reply to Re^2: Problem with passing my script's STDIN to child by jdalbec
in thread Problem with passing my script's STDIN to child by suaveant

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