PHP matches the contents of the specified tag

PHP matches the specified div content, when using PHP to write a collection program, crawling to the Web page data sometimes we only need a small piece of the content of the tag, how can we extract the HTML code, here is a function example, to implement PHP matching any HTML tags in all the content:

/***  matches HTML tag contents of any ID * */function getwebtag ($tag _id, $tag = ' div ', $data =false) {               $charset _pos = stripos ($data, ' CharSet ');         if ($charset _pos)  {             if (Stripos ($data, ' utf-8 ', $charset _pos))  {                  $data  = iconv (' utf-8 ', ' utf-8 ', $data);             }else if (Stripos ($data, ' gb2312 ', $charset _pos))  {                  $data  = iconv (' gb2312 ', ' utf-8 ', $data);             }else if (Stripos ($data, ' GBK ', $charset _pos))  {                  $data  = iconv (' GBK ', ' utf-8 ', $data);             }        }                preg_match_all ('/< '. $ Tag. ' /I ', $data, $pre _matches,preg_offset_capture);     //get all div prefixes          preg_match_all ('/<\/'. $tag. ' /I ', $data, $suf _matches,preg_offset_capture);  //get all div suffixes         $ Hit = strpos ($data, $tag _id);         if ($hit  == -1)  return false;    //misses          $divs  = array ();     //merges all Div        foreach ( $pre _matches[0] as  $index = $pre _div) {             $divs [(int) $pre _div[1]] =  ' P ';              $divs [(int) $suf _matches[0][$index][1]] =  ' s ';            }                //to sort the div         $ Sort = array_keys ($divs);         asort ($sort);                 $count  = count ($pre _ Matches[0]);         foreach ($pre _matches[0] as  $index =>$ Pre_div) {            //<div  $hit  < div+1     when Div is hit             if ($pre _matches[0][$index][1] <  $hit)  &&  ($hit  <  $pre _matches[0][$index +1][1]) {                  $deeper  =  0;                // Pop-up hit Div before div                 while (Array_shift ($sort)  !=  $pre _matches[0][$index][1] &&  ($count-))   continue;                // The remaining div is matched, and if the next is prefixed, a layer down, $deeper plus 1,                 //Otherwise back one layer, $deeper minus 1, $deeper 0 hit match, calculate div length                  foreach ($sort  as  $key) {           &nbsP;         if ($divs [$key] ==  ' P ')   $deeper ++;                      else if ($deeper  == 0)  {                          $length  =  $key-$ pre_matches[0][$index][1];                         break;                     }else {                           $deeper--;                     }                 }                $ Hitdivstring = substr ($data, $pre _matches[0][$index][1], $length). ' </'. $tag. ' > ';                break;             }         }        return  $hitDivString;}

Invoke Example

$html =file_get_contents (' http://www.baidu.com ');

$divContent =getwebtag (' id= ' content ', ' div ', $html);

PHP matches the contents of the specified tag