Testing(some data) at D:\test.pl line 5, <DATA> line 1.
Testing at D:\test.pl line 13.
Testing(some data) at D:\test.pl line 5, <DATA> line 1.
Can't save DATA: Bad file descriptor
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sub Tye
{    
  my $pos= tell(DATA);
  chomp( my $x= <DATA> );
  warn "Testing($x)";
  {
    my $fh= do { local(*FH); \*FH };
    open $fh, "<&DATA"  or  die "Can't save DATA: $!\n";
    close DATA  or  warn "Can't close DATA: $!\n";
    open DATA, "<&=".fileno($fh)  or  die "Can't restore DATA: $!\n";
    seek DATA, $pos, 0  or  die "Can't reposition DATA: $!\n";
  }
  warn "Testing";
}

Tye();
Tye();
__END__
some data
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My mistake. I know this doesn't matter since you found a better solution but this bugged me and I found my mistake.

I was thinking that the "=" in "<&=" was required when using a numeric file descriptor. But the "=" requests an fdopen() instead of a dup(), that is, the new file handle ends up sharing the same file descriptor with the old file handle. So when $fh is closed (triggered when it goes out of scope and gets destroyed), the file descriptor that DATA is using also gets closed out from under it.

So just drop the "=" and my code works.

        - tye (but my friends call me "Tye")