本文实例讲述了PHP自定义函数获取搜索引擎来源关键字的方法。分享给大家供大家参考，具体如下：

获取搜索引擎来源关键字的函数：

function getKeywords() {

// 搜索引擎关键字映射

static $host_keyword_map = array(

'www.baidu.com' => 'wd',

'v.baidu.com' => 'word',

'image.baidu.com' => 'word',

'news.baidu.com' => 'word',

'www.so.com' => 'q',

'video.so.com' => 'q',

'image.so.com' => 'q',

'news.so.com' => 'q',

'www.sogou.com' => 'query',

'pic.sogou.com' => 'query',

'v.sogou.com' => 'query',

);

// 检查来源是否搜索引擎

if (!isset($_SERVER['HTTP_REFERER'])) {

return '';

}

$urls = parse_url($_SERVER['HTTP_REFERER']);

if (!array_key_exists($urls['host'], $host_keyword_map)) {

return '';

}

$key = $host_keyword_map[$urls['host']];

// 检查关键字参数是否存在

if (!isset($urls['query'])) {

return '';

}

$params = array();

parse_str($urls['query'], $params);

if (!isset($params[$key])) {

return '';

}

$keywords = $params[$key];

// 检查编码

$encoding = mb_detect_encoding($keywords, 'utf-8,gbk');

if ($encoding != 'utf-8') {

$keywords = iconv($encoding, 'utf-8', $keywords);

}

return $keywords;

}

函数测试：

header("Content-Type: text/html; charset=utf-8");

$referers = array(

'http://www.baidu.com/s?cl=3&wd=%B9%E9%C0%B4&fr=vid1000',

'http://www.baidu.com/s?tn=92506501_hao_pg&rtt=1&bsst=1&wd=%B9%E9%C0%B4',

'http://www.baidu.com/link?url=ctBhF7AAau6LwE61pJOEH-ZhgUM7D3YHYMrm6xIXJlDQtMXCiea7gg49s90Q-Qh8wHD8Ano-dPNhUawBBNEEwEbtu8toMF5k1V7Xy850EtlpZyMcS0e_y-SCJp86iM6e&wd=%E5%BD%92%E6%9D%A5&tn=baidu&ie=utf-8&inputT=2980',

'http://www.baidu.com/link?url=TIn9NR6fwiy6IwwkCcVF8HhHoxVUpHQsyj1YdlQPy2roXKTnSQS_3UxwvyjZ2JPkpxF8-diSoRCSpODUM_jq2K&wd=%E5%BD%92%E6%9D%A5&tn=baidu&ie=utf-8&input',

'http://news.baidu.com/ns?cl=2&rn=20&tn=news&word=%E5%BD%92%E6%9D%A5&ie=utf-8',

'http://image.baidu.com/i?ct=503316480&z=&tn=baiduimagedetail&ipn=d&word=%E5%BD%92%E6%9D%A5&step_word=&ie=utf-8&in=17668&cl=2&lm=-1&st=&pn=6&rn=1&di=70447907090&ln=1994&fr=news&&fmq=1402285886106_R&ic=&s=&se=&sme=0&tab=&width=&height=&face=&is=&istype=&ist=&jit=&objurl=http%3A%2F%2Fpic31.nipic.com%2F20130713%2F1287761_225159187345_2.jpg',

'http://v.baidu.com/v?ct=301989888&s=25&ie=utf-8&word=%E5%BD%92%E6%9D%A5',

'http://www.so.com/s?ie=utf-8&shb=1&src=360sou_newhome&q=%E5%BD%92%E6%9D%A5',

'http://video.so.com/v?q=%E5%BD%92%E6%9D%A5&src=tab_www',

'http://image.so.com/v?q=%E5%BD%92%E6%9D%A5&src=tab_video&fromurl=http%3A%2F%2Fndent.oeeee.com%2Fhtml%2F201309%2F16%2F258899.html',

'http://news.so.com/ns?q=%E5%BD%92%E6%9D%A5&src=tab_video',

'http://www.sogou.com/web?query=%E5%BD%92%E6%9D%A5&_asf=www.sogou.com&_ast=1402284372&w=01019900&p=40040100&ie=utf8&sut=6558&sst0=1402284372272&lkt=0%2C0%2C0',

'http://www.sogou.com/web?query=%E5%BD%92%E6%9D%A5&_asf=www.sogou.com&_ast=1402284372&w=01019900&p=40040100&ie=utf8&sut=6558&sst0=1402284372272&lkt=0%2C0%2C0',

'http://pic.sogou.com/d?query=%B9%E9%C0%B4&mood=0&picformat=0&mode=1&di=0&w=03021800&dr=1&did=1',

'http://v.sogou.com/v?query=%B9%E9%C0%B4&p=&w=',

'http://www.baidu.com/s?aaa=bbb',

'http://www.baidu.com/',

'http://www.jb51.net/',

);

foreach ($referers as $r) {

$_SERVER['HTTP_REFERER'] = $r;

echo getKeywords(), "\n";

}

希望本文所述对大家PHP程序设计有所帮助。