<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">##
## Generic data connection package
##

package Net::FTP::dataconn;

use 5.008001;

use strict;
use warnings;

use Carp;
use Errno;
use Net::Cmd;

our $VERSION = '3.14';

$Net::FTP::IOCLASS or die "please load Net::FTP before Net::FTP::dataconn";
our @ISA = $Net::FTP::IOCLASS;

sub reading {
  my $data = shift;
  ${*$data}{'net_ftp_bytesread'} = 0;
}


sub abort {
  my $data = shift;
  my $ftp  = ${*$data}{'net_ftp_cmd'};

  # no need to abort if we have finished the xfer
  return $data-&gt;close
    if ${*$data}{'net_ftp_eof'};

  # for some reason if we continuously open RETR connections and not
  # read a single byte, then abort them after a while the server will
  # close our connection, this prevents the unexpected EOF on the
  # command channel -- GMB
  if (exists ${*$data}{'net_ftp_bytesread'}
    &amp;&amp; (${*$data}{'net_ftp_bytesread'} == 0))
  {
    my $buf     = "";
    my $timeout = $data-&gt;timeout;
    $data-&gt;can_read($timeout) &amp;&amp; sysread($data, $buf, 1);
  }

  ${*$data}{'net_ftp_eof'} = 1;    # fake

  $ftp-&gt;abort;                     # this will close me
}


sub _close {
  my $data = shift;
  my $ftp  = ${*$data}{'net_ftp_cmd'};

  $data-&gt;SUPER::close();

  delete ${*$ftp}{'net_ftp_dataconn'}
    if defined $ftp
    &amp;&amp; exists ${*$ftp}{'net_ftp_dataconn'}
    &amp;&amp; $data == ${*$ftp}{'net_ftp_dataconn'};
}


sub close {
  my $data = shift;
  my $ftp  = ${*$data}{'net_ftp_cmd'};

  if (exists ${*$data}{'net_ftp_bytesread'} &amp;&amp; !${*$data}{'net_ftp_eof'}) {
    my $junk;
    eval { local($SIG{__DIE__}); $data-&gt;read($junk, 1, 0) };
    return $data-&gt;abort unless ${*$data}{'net_ftp_eof'};
  }

  $data-&gt;_close;

  return unless defined $ftp;

  $ftp-&gt;response() == CMD_OK
    &amp;&amp; $ftp-&gt;message =~ /unique file name:\s*(\S*)\s*\)/
    &amp;&amp; (${*$ftp}{'net_ftp_unique'} = $1);

  $ftp-&gt;status == CMD_OK;
}


sub _select {
  my ($data, $timeout, $do_read) = @_;
  my ($rin, $rout, $win, $wout, $tout, $nfound);

  vec($rin = '', fileno($data), 1) = 1;

  ($win, $rin) = ($rin, $win) unless $do_read;

  while (1) {
    $nfound = select($rout = $rin, $wout = $win, undef, $tout = $timeout);

    last if $nfound &gt;= 0;

    croak "select: $!"
      unless $!{EINTR};
  }

  $nfound;
}


sub can_read {
  _select(@_[0, 1], 1);
}


sub can_write {
  _select(@_[0, 1], 0);
}


sub cmd {
  my $ftp = shift;

  ${*$ftp}{'net_ftp_cmd'};
}


sub bytes_read {
  my $ftp = shift;

  ${*$ftp}{'net_ftp_bytesread'} || 0;
}

1;

__END__

=head1 NAME

Net::FTP::dataconn - FTP Client data connection class

=head1 SYNOPSIS

    # Perform IO operations on an FTP client data connection object:

    $num_bytes_read = $obj-&gt;read($buffer, $size);
    $num_bytes_read = $obj-&gt;read($buffer, $size, $timeout);

    $num_bytes_written = $obj-&gt;write($buffer, $size);
    $num_bytes_written = $obj-&gt;write($buffer, $size, $timeout);

    $num_bytes_read_so_far = $obj-&gt;bytes_read();

    $obj-&gt;abort();

    $closed_successfully = $obj-&gt;close();

=head1 DESCRIPTION

Some of the methods defined in C&lt;Net::FTP&gt; return an object which will
be derived from this class. The dataconn class itself is derived from
the C&lt;IO::Socket::INET&gt; class, so any normal IO operations can be performed.
However the following methods are defined in the dataconn class and IO should
be performed using these.

=over 4

=item C&lt;read($buffer, $size[, $timeout])&gt;

Read C&lt;$size&gt; bytes of data from the server and place it into C&lt;$buffer&gt;, also
performing any &lt;CRLF&gt; translation necessary. C&lt;$timeout&gt; is optional, if not
given, the timeout value from the command connection will be used.

Returns the number of bytes read before any &lt;CRLF&gt; translation.

=item C&lt;write($buffer, $size[, $timeout])&gt;

Write C&lt;$size&gt; bytes of data from C&lt;$buffer&gt; to the server, also
performing any &lt;CRLF&gt; translation necessary. C&lt;$timeout&gt; is optional, if not
given, the timeout value from the command connection will be used.

Returns the number of bytes written before any &lt;CRLF&gt; translation.

=item C&lt;bytes_read()&gt;

Returns the number of bytes read so far.

=item C&lt;abort()&gt;

Abort the current data transfer.

=item C&lt;close()&gt;

Close the data connection and get a response from the FTP server. Returns
I&lt;true&gt; if the connection was closed successfully and the first digit of
the response from the server was a '2'.

=back

=head1 EXPORTS

I&lt;None&gt;.

=head1 KNOWN BUGS

I&lt;None&gt;.

=head1 AUTHOR

Graham Barr E&lt;lt&gt;L&lt;gbarr@pobox.com|mailto:gbarr@pobox.com&gt;E&lt;gt&gt;.

Steve Hay E&lt;lt&gt;L&lt;shay@cpan.org|mailto:shay@cpan.org&gt;E&lt;gt&gt; is now maintaining
libnet as of version 1.22_02.

=head1 COPYRIGHT

Copyright (C) 1997-2010 Graham Barr.  All rights reserved.

Copyright (C) 2013-2014, 2020 Steve Hay.  All rights reserved.

=head1 LICENCE

This module is free software; you can redistribute it and/or modify it under the
same terms as Perl itself, i.e. under the terms of either the GNU General Public
License or the Artistic License, as specified in the F&lt;LICENCE&gt; file.

=head1 VERSION

Version 3.14

=head1 DATE

23 Dec 2020

=head1 HISTORY

See the F&lt;Changes&gt; file.

=cut
</pre></body></html>