File: //usr/share/perl/5.34/Net/FTP/I.pm
## 
## Package to read/write on BINARY data connections
##
package Net::FTP::I;
use 5.008001;
use strict;
use warnings;
use Carp;
use Net::FTP::dataconn;
our @ISA     = qw(Net::FTP::dataconn);
our $VERSION = "3.13";
our $buf;
sub read {
  my $data = shift;
  local *buf = \$_[0];
  shift;
  my $size = shift || croak 'read($buf,$size,[$timeout])';
  my $timeout = @_ ? shift: $data->timeout;
  my $n;
  if ($size > length ${*$data} and !${*$data}{'net_ftp_eof'}) {
    $data->can_read($timeout)
      or croak "Timeout";
    my $blksize = ${*$data}{'net_ftp_blksize'};
    $blksize = $size if $size > $blksize;
    unless ($n = sysread($data, ${*$data}, $blksize, length ${*$data})) {
      return unless defined $n;
      ${*$data}{'net_ftp_eof'} = 1;
    }
  }
  $buf = substr(${*$data}, 0, $size);
  $n = length($buf);
  substr(${*$data}, 0, $n) = '';
  ${*$data}{'net_ftp_bytesread'} += $n;
  $n;
}
sub write {
  my $data = shift;
  local *buf = \$_[0];
  shift;
  my $size = shift || croak 'write($buf,$size,[$timeout])';
  my $timeout = @_ ? shift: $data->timeout;
  # If the remote server has closed the connection we will be signal'd
  # when we write. This can happen if the disk on the remote server fills up
  local $SIG{PIPE} = 'IGNORE'
    unless ($SIG{PIPE} || '') eq 'IGNORE'
    or $^O eq 'MacOS';
  my $sent = $size;
  my $off  = 0;
  my $blksize = ${*$data}{'net_ftp_blksize'};
  while ($sent > 0) {
    $data->can_write($timeout)
      or croak "Timeout";
    my $n = syswrite($data, $buf, $sent > $blksize ? $blksize : $sent, $off);
    return unless defined($n);
    $sent -= $n;
    $off += $n;
  }
  $size;
}
1;