i.pm

来自「source of perl for linux application,」· PM 代码 · 共 81 行

## 
## Package to read/write on BINARY data connections
##

package Net::FTP::I;

use vars qw(@ISA $buf $VERSION);
use Carp;

require Net::FTP::dataconn;

@ISA     = qw(Net::FTP::dataconn);
$VERSION = "1.12";


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 undef 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, $off);
    return undef unless defined($n);
    $sent -= $n;
    $off += $n;
  }

  $size;
}

1;