1. Apach服务器下可以直接使用 PHP自带函数获取客户端HTTP请求头信息

1. /*
2. 作用：获取客户端HTTP请求所有头信息（header）
3. 参数：无。
4. 返回：HTTP请求所有头信息数组
5. */
6. getallheaders()

 实例：

1. <?php
2. var_dump(getallheaders());

==>输出

1. array(12) {
2. ["Content-Type"] => string(0) ""
3. ["Content-Length"] => string(1) "0"
4. ["X-Original-Url"] => string(21) "/Home/Other/getHeader"
5. ["Upgrade-Insecure-Requests"] => string(1) "1"
6. ["User-Agent"] => string(114) "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.119 Safari/537.36"
7. ["Host"] => string(17) "www.example.com"
8. ["Cookie"] => string(36) "PHPSESSID=7rjh2uomb8477dggmr85bg9067"
9. ["Accept-Language"] => string(14) "zh-CN,zh;q=0.9"
10. ["Accept-Encoding"] => string(13) "gzip, deflate"
11. ["Accept"] => string(85) "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8"
12. ["Connection"] => string(10) "keep-alive"
13. ["Cache-Control"] => string(9) "max-age=0"
14. }

2.  非apach环境下，可根据服务器$_SERVER信息获取HTTP请求的header信息，设计函数：

1. function getHeader() {
2. $headers = array();
3. foreach ($_SERVER as $key => $value) {
4. if ('HTTP_' == substr($key, 0, 5)) {
5. $headers[str_replace('_', '-', substr($key, 5))] = $value;
6. }
7. if (isset($_SERVER['PHP_AUTH_DIGEST'])) {
8. $header['AUTHORIZATION'] = $_SERVER['PHP_AUTH_DIGEST'];
9. } elseif (isset($_SERVER['PHP_AUTH_USER']) && isset($_SERVER['PHP_AUTH_PW'])) {
10. $header['AUTHORIZATION'] = base64_encode($_SERVER['PHP_AUTH_USER'] . ':' . $_SERVER['PHP_AUTH_PW']);
11. }
12. if (isset($_SERVER['CONTENT_LENGTH'])) {
13. $header['CONTENT-LENGTH'] = $_SERVER['CONTENT_LENGTH'];
14. }
15. if (isset($_SERVER['CONTENT_TYPE'])) {
16. $header['CONTENT-TYPE'] = $_SERVER['CONTENT_TYPE'];
17. }
18. }
19. return $headers;
20. }

实例：

1. <?php
2. var_dump(getHeader());

==>输出

1. array(11) {
2. ["X-ORIGINAL-URL"] => string(21) "/Home/Other/getHeader"
3. ["UPGRADE-INSECURE-REQUESTS"] => string(1) "1"
4. ["USER-AGENT"] => string(114) "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.119 Safari/537.36"
5. ["HOST"] => string(17) "www.example.com"
6. ["COOKIE"] => string(36) "PHPSESSID=7rjh2uomb8477dggmr85bg9067"
7. ["ACCEPT-LANGUAGE"] => string(14) "zh-CN,zh;q=0.9"
8. ["ACCEPT-ENCODING"] => string(13) "gzip, deflate"
9. ["ACCEPT"] => string(85) "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8"
10. ["CONTENT-LENGTH"] => string(1) "0"
11. ["CONNECTION"] => string(10) "keep-alive"
12. ["CACHE-CONTROL"] => string(9) "max-age=0"
13. }

三、获取服务器HTTP响应header信息

1. /*
2. 作用：获取服务器响应一个 HTTP 请求所发送的所有标头
3. 参数：
4. url：目标 URL；
5. format：如果将可选的 format 参数设为 1，则 get_headers() 会解析相应的信息并设定数组的键名。
6. 返回：返回包含有服务器响应一个 HTTP 请求所发送标头的索引或关联数组，如果失败则返回 FALSE。
7. */
8. get_headers ( string $url [,int $format = 0 ] )

实例：

1. <?php
2. $url = 'http://www.example.com';
3. print_r(get_headers($url));
4. print_r(get_headers($url, 1));
5. ?>

==>输出

1. Array
2. (
3. [0] => HTTP/1.1 200 OK
4. [1] => Date: Sat, 29 May 2004 12:28:13 GMT
5. [2] => Server: Apache/1.3.27 (Unix) (Red-Hat/Linux)
6. [3] => Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
7. [4] => ETag: "3f80f-1b6-3e1cb03b"
8. [5] => Accept-Ranges: bytes
9. [6] => Content-Length: 438
10. [7] => Connection: close
11. [8] => Content-Type: text/html
12. )
14. Array
15. (
16. [0] => HTTP/1.1 200 OK
17. [Date] => Sat, 29 May 2004 12:28:14 GMT
18. [Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux)
19. [Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT
20. [ETag] => "3f80f-1b6-3e1cb03b"
21. [Accept-Ranges] => bytes
22. [Content-Length] => 438
23. [Connection] => close
24. [Content-Type] => text/html
25. )

四，参考资料

1.  https://www.yiibai.com/manual/php/function.get-headers.html

2.  https://www.oschina.net/question/54100_38761

3.  https://blog.csdn.net/xuezhiwu001/article/details/61203045