php获取页面指定标签内容的实现代码分享
可以匹配任意可闭合带id标签
<?php
header ( "Content-type: text/html; charset=utf-8" );
/*
* 参数说明: $tag_id:所要获取的元素Tag Id $url:所要获取页面的Url $tag:所要获取的标签 $data
*/
function getWebTag($tag_id, $url = false, $tag = 'div', $data = false) {
if ($url !== false) {
$data = file_get_contents ( $url );
}
$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 ); // 获取所有div前缀
preg_match_all ( '/<\/' . $tag . '/i', $data, $suf_matches, PREG_OFFSET_CAPTURE ); // 获取所有div后缀
$hit = strpos ( $data, $tag_id );
if ($hit == - 1)
return false; // 未命中
$divs = array (); // 合并所有div
foreach ( $pre_matches [0] as $index => $pre_div ) {
$divs [( int ) $pre_div [1]] = 'p';
$divs [( int ) $suf_matches [0] [$index] [1]] = 's';
}
// 对div进行排序
$sort = array_keys ( $divs );
asort ( $sort );
$count = count ( $pre_matches [0] );
foreach ( $pre_matches [0] as $index => $pre_div ) {
// <div $hit <div+1 时div被命中
if (($pre_matches [0] [$index] [1] < $hit) && ($hit < $pre_matches [0] [$index + 1] [1])) {
$deeper = 0;
// 弹出被命中div前的div
while ( array_shift ( $sort ) != $pre_matches [0] [$index] [1] && ($count --) )
continue;
// 对剩余div进行匹配，若下一个为前缀，则向下一层，$deeper加1，
// 否则后退一层，$deeper减1，$deeper为0则命中匹配，计算div长度
foreach ( $sort as $key ) {
if ($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;
}
//test
echo getWebTag ( 'id="content"', 'http://www.cnblogs.com/suizhikuo/archive/2012/11/17/2774956.html', 'div' );
?>
