PHP編程
<?php
function mask2bin($n)
{
  $n = intval($n);
  if($n<0||$n>32) 
  die('error submask');
  return str_repeat("1", $n).str_repeat("0",32-$n);
}
function revBin($s)
{
  $p=array('0','1','2');
  $r=array('2','0','1');
 
  return str_replace($p,$r,$s);
}
function startIp($str,$bSub)
{
  $bIp = decbin($str);
  $bIp = str_pad($bIp,8,"0",STR_PAD_LEFT);
  $sIp = bindec($bIp & $bSub);
  return $sIp;
}
function endIp($str,$bSub)
{
  $bIp = decbin($str);
  $bIp = str_pad($bIp,8,"0",STR_PAD_LEFT);
  $eIp = bindec($bIp | revBin($bSub));
  return $eIp;
}
$ip = array('192','168','1','5');//設定IP地址,可以從表單獲取,這里只作演示
$mask = '24';          //設置掩碼
$bSub = mask2bin($mask);     //將子網掩碼轉換二進制
$mask = array();
$mask[] = substr($bSub,"0",8);  //將子網掩碼每8位分一段
$mask[] = substr($bSub,"8",8);
$mask[] = substr($bSub,"16",8);
$mask[] = substr($bSub,"24",8);
echo '<table summary="result" border="1" cellspacing="1" cellpadding="0" >
 <tbody>
  <td align="right" ><font size="2">掩碼:</font></td>
  <td>
  <font size="2">';
for ($i=0;$i<4;$i++)
{
  echo bindec($mask[$i]);
  if($i!=3)
  echo ".";
}
echo '</font>
  </td>
  </tr>
 <tr>
  <td align="right"><font size="2">網絡地址:</font></td>
  <td>
  <font size="2">';
  for ($i=0;$i<4;$i++)
  {
   echo startIp($ip[$i],$mask[$i]);
   if($i!=3)
   echo ".";
  }
echo '</font> 
  </td>
  </tr>
    </td>
  </tr>
 <tr>
  <td align="right"><font size="2">第一個可用:</font></td>
  <td>
  <font size="2">';
  for ($i=0;$i<3;$i++)
  {   
   echo startIp($ip[$i],$mask[$i]);  
   echo ".";
  }
  $ip_4 = startIp($ip[3],$mask[3]);
  echo ++$ip_4;
  echo '</font> 
  </td>
  </tr>
 <tr>
  <td align="right"><font size="2">最后可用:</font></td>
  <td>
  <font size="2">';
  for ($i=0;$i<3;$i++)
  {
   echo endIp($ip[$i],$mask[$i]);
   echo ".";
  }
  $ip_4 = endIp($ip[3],$mask[3]);
  echo --$ip_4;
echo '
  </font>
  </td>
  </tr>
 <tr>
  <td align="right"><font size="2">廣播地址:</font></td>
  <td>
  <font size="2">';
  for ($i=0;$i<4;$i++)
  {
   echo endIp($ip[$i],$mask[$i]);
   if($i!=3)
   echo ".";
  }
?>