Thanks to both crenz and runrig.

I followed up on the leads crenz presented here. He is right. In the get() of Net::FTP, it calls syswrite to write to the local file, and that's the whole problem.

Now it is clear that syswrite obviously does not work with in-mem.

I changed the syswrite to a print. As I don't want that impact the normal get(), I added one function called get_in_mem() to Net::FTP on my PC.

I simply replicated get(), changed that syswrite to print, and striped some code that is obviously not neccessary for opened handlers (as the original get() also deals with filenames).

Here is the code (obviously I didn't fully test it, but for my case, I tested it and it worked): 
sub get_in_mem {
    my($ftp,$remote,$local,$where) = @_;

    my($loc,$len,$buf,$resp,$data);
    local *FD;

    my $localfd = 1;

    croak("Bad remote filename '$remote'\n") if $remote =~ /[\r\n]/s;

    ${*$ftp}{'net_ftp_rest'} = $where if ($where);

    delete ${*$ftp}{'net_ftp_port'};
    delete ${*$ftp}{'net_ftp_pasv'};

    $data = $ftp->retr($remote) or return undef;

    $loc = $local;
    
    if($ftp->type eq 'I' && !binmode($loc)) {
        carp "Cannot binmode Local file $local: $!\n";
        $data->abort;
        return undef;
    }

    $buf = '';
    my($count,$hashh,$hashb,$ref) = (0);

    ($hashh,$hashb) = @$ref if($ref = ${*$ftp}{'net_ftp_hash'});

    my $blksize = ${*$ftp}{'net_ftp_blksize'};

    while(1) {
        last unless $len = $data->read($buf,$blksize);

        if (trEBCDIC && $ftp->type ne 'I')
        {
            $buf = $ftp->toebcdic($buf);
            $len = length($buf);
        }

        if($hashh) {
            $count += $len;
            print $hashh "#" x (int($count / $hashb));
            $count %= $hashb;
        }
        print $loc $buf;
=document
        my $written = syswrite($loc,$buf,$len);
        unless(defined($written) && $written == $len)
        {
            carp "Cannot write to Local file $local: $!\n";
            $data->abort;
            close($loc)
            unless $localfd;
            return undef;
        }
=cut
    }

    print $hashh "\n" if $hashh;

    unless ($data->close()) # implied $ftp->response
    {
        carp "Unable to close datastream";
        return undef;
    }

    return $local;
}

[download]

In reply to Re: Re: question about Net::FTP + in memory file handler by pg
in thread question about Net::FTP + in memory file handler by pg

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! —
  • 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:
    & &amp;
    < &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.