本文实例讲述了php读取torrent种子文件内容的方法。分享给大家供大家参考，具体如下：

/**

* Class xBEncoder

* Author: Angus.Fenying

* Version: 0.1

* Date: 2014-06-03

*

* This class helps stringify or parse BENC

* codes.

*

* All Copyrights 2007 - 2014 Fenying Studio Reserved.

*/

class xBEncoder

{

const READY = 0;

const READ_STR = 1;

const READ_DICT = 2;

const READ_LIST = 3;

const READ_INT = 4;

const READ_KEY = 5;

public $y;

protected $z, $m, $n;

protected $stat;

protected $stack;

/**

* This method saves the status of current

* encode/decode work.

*/

protected function push($newY, $newStat)

{

array_push($this->stack, array($this->y, $this->z, $this->m, $this->n, $this->stat));

list($this->y, $this->z, $this->m, $this->n, $this->stat) = array($newY, 0, 0, 0, $newStat);

}

/**

* This method restore the saved status of current

* encode/decode work.

*/

protected function pop()

{

$t = array_pop($this->stack);

if ($t) {

if ($t[4] == self::READ_DICT) {

$t[0]->{$t[1]} = $this->y;

$t[1] = 0;

} elseif ($t[4] == self::READ_LIST)

$t[0][] = $this->y;

list($this->y, $this->z, $this->m, $this->n, $this->stat) = $t;

}

}

/**

* This method initializes the status of work.

* YOU SHOULD CALL THIS METHOD BEFORE EVERYTHING.

*/

public function init()

{

$this->stat = self::READY;

$this->stack = array();

$this->z = $this->m = $this->n = 0;

}

/**

* This method decode $s($l as length).

* You can get $obj->y as the result.

*/

public function decode($s, $l)

{

$this->y = 0;

for ($i = 0; $i < $l; ++$i) {

switch ($this->stat) {

case self::READY:

if ($s[$i] == 'd') {

$this->y = new xBDict();

$this->stat = self::READ_DICT;

} elseif ($s[$i] == 'l') {

$this->y = array();

$this->stat = self::READ_LIST;

}

break;

case self::READ_INT:

if ($s[$i] == 'e') {

$this->y->val = substr($s, $this->m, $i - $this->m);

$this->pop();

}

break;

case self::READ_STR:

if (xBInt::isNum($s[$i]))

continue;

if ($s[$i] = ':') {

$this->z = substr($s, $this->m, $i - $this->m);

$this->y = substr($s, $i + 1, $this->z + 0);

$i += $this->z;

$this->pop();

}

break;

case self::READ_KEY:

if (xBInt::isNum($s[$i]))

continue;

if ($s[$i] = ':') {

$this->n = substr($s, $this->m, $i - $this->m);

$this->z = substr($s, $i + 1, $this->n + 0);

$i += $this->n;

$this->stat = self::READ_DICT;

}

break;

case self::READ_DICT:

if ($s[$i] == 'e') {

$this->pop();

break;

} elseif (!$this->z) {

$this->m = $i;

$this->stat = self::READ_KEY;

break;

}

case self::READ_LIST:

switch ($s[$i]) {

case 'e':

$this->pop();

break;

case 'd':

$this->push(new xBDict(), self::READ_DICT);

break;

case 'i':

$this->push(new xBInt(), self::READ_INT);

$this->m = $i + 1;

break;

case 'l':

$this->push(array(), self::READ_LIST);

break;

default:

if (xBInt::isNum($s[$i])) {

$this->push('', self::READ_STR);

$this->m = $i;

}

}

break;

}

}

$rtn = empty($this->stack);

$this->init();

return $rtn;

}

/**

* This method encode $obj->y into BEncode.

*/

public function encode()

{

return $this->_encDo($this->y);

}

protected function _encStr($str)

{

return strlen($str) . ':' . $str;

}

protected function _encDo($o)

{

if (is_string($o))

return $this->_encStr($o);

if ($o instanceof xBInt)

return 'i' . $o->val . 'e';

if ($o instanceof xBDict) {

$r = 'd';

foreach ($o as $k => $c)

$r .= $this->_encStr($k) . $this->_encDo($c);

return $r . 'e';

}

if (is_array($o)) {

$r = 'l';

foreach ($o as $c)

$r .= $this->_encDo($c);

return $r . 'e';

}

}

}

class xBDict

{

}

class xBInt

{

public $val;

public function __construct($val = 0)

{

$this->val = $val;

}

public static function isNum($chr)

{

$chr = ord($chr);

if ($chr <= 57 && $chr >= 48)

return true;

return false;

}

}

//使用实例

$s = file_get_contents("test.torrent");

$bc = new xBEncoder();

$bc->init();

$bc->decode($s, strlen($s));

var_dump($bc->y);

希望本文所述对大家PHP程序设计有所帮助。