get_headers是获取http头信息，get_meta_tags是获取网页的description,abstract,keywords等信息
get_headers是获取http头信息，get_meta_tags是获取网页的description,abstract,keywords等信息
*/
$url='http://www.bKjia.c0m'; //定义url
print_r(get_headers($url)); //无格式获取
print_r(get_headers($url,1)); //带上格式获取
/*
array
(
[0] => http/1.1 200 ok
[1] => connection: close
[2] => date: sat, 11 dec 2010 05:43:46 gmt
[3] => content-length: 69617
[4] => content-type: text/html
[5] => content-location: http://www.bKjia.c0m/index.html
[6] => last-modified: sat, 11 dec 2010 05:19:51 gmt
[7] => accept-ranges: bytes
[8] => etag: "e8be4b9f398cb1:6c66"
[9] => server: microsoft-iis/6.0
[10] => x-powered-by: asp教程.net
)
array
(
[0] => http/1.1 200 ok
[connection] => close
[date] => sat, 11 dec 2010 05:43:47 gmt
[content-length] => 69617
[content-type] => text/html
[content-location] => http://www.bKjia.c0m/index.html
[last-modified] => sat, 11 dec 2010 05:19:51 gmt
[accept-ranges] => bytes
[etag] => "e8be4b9f398cb1:6c66"
[server] => microsoft-iis/6.0
[x-powered-by] => asp.net教程
)
get_meta_tags($url);
获取指定网页的description,abstract,keywords等信息
*/
$tags=get_meta_tags('http://www.bKjia.c0m/'); //提取meta标签
print_r($tags) //输出数组全部内容
/*
array
(
[description] => 网页制作教程网提供专业网页设计教程与网页制作教程包括有photoshop教程,flash,html,css教程,dreamweaver,fireworks,asp,php教程,jsp教程,asp.net,网站建设,网站开发,网页特效,平面设计,个人网站,网页素材
[abstract] => 提供最新的网页制作教程、网页设计教程、网页特效，为个人网站提供网页素材模板和网页视频学习。
[keywords] => 网页设计教程,网页制作教程,网页学习,photoshop,flash,html,css,dreamweaver,fireworks,asp,php,jsp,asp.net,网页特效,平面设计,网页素材
)
注意：使用该函数需要把 php.ini里面的allow_url_fopen = on，才能使用
