이 에러 좀 봐주세요.

[Fri May 19 19:52:34.957972 2017] [:error] [pid 17786] [client 172.30.1.254:56178] PHP Notice:  Only variables should be passed by reference in /home/html/plugin/torrent/bencode.php on line 145 [Fri May 19 19:52:34.958075 2017] [:error] [pid 17786] [client 172.30.1.254:56178] PHP Notice:  Only variables should be passed by reference in /home/html/plugin/torrent/bencode.php on line 160 [Fri May 19 19:52:34.958094 2017] [:error] [pid 17786] [client 172.30.1.254:56178] PHP Notice:  Only variable references should be returned by reference in /home/html/plugin/torrent/bencode.php on line 65

에러 내용입니다. 65줄 145줄 160줄에 에러가 있다고 나옵니다.

아래는 bencode.php 코드입니다. 

http://torrenteditor.com">http://torrenteditor.com IRC: #torrenteditor.com on efnet.org     This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.   This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.   You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/">http://www.gnu.org/licenses/>. */   class BEncode {     public static function &decode( &$raw, &$offset=0 )     {            if ( $offset >= strlen( $raw ) )         {             return new BEncode_Error( "Decoder exceeded max length." ) ;         }                  $char = $raw[$offset];         switch ( $char )         {             case 'i':                 $int = new BEncode_Int();                 $int->decode( $raw, $offset );                 return $int;                              case 'd':                 $dict = new BEncode_Dictionary();                   if ( $check = $dict->decode( $raw, $offset ) )                 {                     return $check;                 }                 return $dict;                              case 'l':                 $list = new BEncode_List();                 $list->decode( $raw, $offset );                 return $list;                              case 'e':                 $ret = new BEncode_End();                      return $ret;                               case '0':             case is_numeric( $char ):                 $str = new BEncode_String();                 $str->decode( $raw, $offset );                 return $str;               default:                 return new BEncode_Error( "Decoder encountered unknown char '$char' at offset $offset." );         }     } }   class BEncode_End {     public function get_type()     {         return 'end';     } }   class BEncode_Error {     private $error;          public function BEncode_Error( $error )     {         $this->error = $error;     }          public function get_plain()     {         return $this->error;     }          public function get_type()     {         return 'error';     } }   class BEncode_Int {     private $value;          public function BEncode_Int( $value = null )     {         $this->value = $value;     }       public function decode( &$raw, &$offset )     {             $end = strpos( $raw, 'e', $offset );             $this->value = substr( $raw, ++$offset, $end - $offset );             $offset += ( $end - $offset );     }       public function get_plain()     {         return $this->value;     }       public function get_type()     {         return 'int';     }          public function encode()     {         return "i{$this->value}e";     }          public function set( $value )     {         $this->value = $value;     } }   class BEncode_Dictionary {     public $value = array();          public function decode( &$raw, &$offset )     {             $dictionary = array();               while ( true )             {                 $name = BEncode::decode( $raw, ++$offset );                   if ( $name->get_type() == 'end' )                 {                     break;                 }                 else if ( $name->get_type() == 'error' )                 {                     return $name;                 }                 else if ( $name->get_type() != 'string' )                 {                     return new BEncode_Error( "Key name in dictionary was not a string." );                 }                   $value = BEncode::decode( $raw, ++$offset );                   if ( $value->get_type() == 'error' )                 {                     return $value;                 }                   $dictionary[$name->get_plain()] = $value;             }               $this->value = $dictionary;     }          public function get_value( $key )     {         if ( isset( $this->value[$key] ) )         {             return $this->value[$key];         }         else         {             return null;         }     }          public function encode()     {         $this->sort();           $encoded = 'd';         while ( list( $key, $value ) = each( $this->value ) )         {             $bstr = new BEncode_String();             $bstr->set( $key );             $encoded .= $bstr->encode();             $encoded .= $value->encode();         }         $encoded .= 'e';         return $encoded;     }       public function get_type()     {         return 'dictionary';     }          public function remove( $key )     {         unset( $this->value[$key] );     }          public function set( $key, $value )     {         $this->value[$key] = $value;     }          private function sort()     {         ksort( $this->value );     }          public function count()     {         return count( $this->value );     } }   class BEncode_List {     private $value = array();          public function add( $bval )     {         array_push( $this->value, $bval );     }       public function decode( &$raw, &$offset )     {             $list = array();               while ( true )             {                 $value = BEncode::decode( $raw, ++$offset );                   if ( $value->get_type() == 'end' )                 {                     break;                 }                 else if ( $value->get_type() == 'error' )                 {                     return $value;                 }                 array_push( $list, $value );             }               $this->value = $list;     }          public function encode()     {         $encoded = 'l';                  for ( $i = 0; $i < count( $this->value ); ++$i )         {             $encoded .= $this->value[$i]->encode();         }         $encoded .= 'e';         return $encoded;     }          public function get_plain()     {         return $this->value;     }       public function get_type()     {         return 'list';     } }   class BEncode_String {     private $value;          public function BEncode_String( $value = null )     {         $this->value = $value;     }          public function decode( &$raw, &$offset )     {             $end = strpos( $raw, ':', $offset );             $len = substr( $raw, $offset, $end - $offset );             $offset += ($len + ($end - $offset));             $end++;             $this->value = substr( $raw, $end, $len );     }          public function get_plain()     {         return $this->value;     }          public function get_type()     {         return 'string';     }          public function encode()     {         $len = strlen( $this->value );         return  "$len:{$this->value}";     }          public function set( $value )     {         $this->value = $value;     } }   ?>

라인 65:                 return new BEncode_Error( "Decoder encountered unknown char '$char' at offset $offset." );

라인 145:                 $name = BEncode::decode( $raw, ++$offset );

라인 160:                $value = BEncode::decode( $raw, ++$offset );

이네요.

뭐가 잘못됐는지 모르겠어요. 도움 좀 부탁드립니다.