PHP实现读取远程文件功能

在昨天做端口测试的基础上研究一下PHP上传与下载的代码，结果想起前段时间笔试题有一道题是在上传文件时显示文件内容，让我对PHP实现读取远程文件的功能很感兴趣，以下是代码：

01	function urlfopen($url, $limit = 0, $post = '', $cookie = '', $bysocket = FALSE , $ip = '', $timeout = 15, $block = TRUE, $encodetype = 'URLENCODE') {

02	$return = '';

03	$matches = parse_url($url);

04	$host = $matches['host'];

05	$path = $matches['path'] ? $matches['path'].(isset($matches['query']) ? '?'.$matches['query'] : '') : '/';

06	$port = !empty($matches['port']) ? $matches['port'] : 80;

07

08	if($post) {

09	$out = "POST $path HTTP/1.0\r\n";

10	$out .= "Accept: */*\r\n";

11	$out .= "Accept-Language: zh-cn\r\n";

12	$boundary = $encodetype == 'URLENCODE' ? '' : ';'.substr($post, 0, trim(strpos($post, "\n")));

13	$out .= $encodetype == 'URLENCODE' ? "Content-Type: application/x-www-form-urlencoded\r\n" : "Content-Type: multipart/form-data$boundary\r\n";

14	$out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";

15	$out .= "Host: $host\r\n";

16	$out .= 'Content-Length: '.strlen($post)."\r\n";

17	$out .= "Connection: Close\r\n";

18	$out .= "Cache-Control: no-cache\r\n";

19	$out .= "Cookie: $cookie\r\n\r\n";

20	$out .= $post;

21

} else {

22	$out = "GET $path HTTP/1.0\r\n";

23	$out .= "Accept: */*\r\n";

24	$out .= "Accept-Language: zh-cn\r\n";

25	$out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";

26	$out .= "Host: $host\r\n";

27	$out .= "Referer: \r\n";

28	$out .= "Connection: Close\r\n";

29	$out .= "Cookie: $cookie\r\n\r\n";

30

}

31	$fp = @fsockopen(($ip ? $ip : $host), $port, $errno, $errstr,$timeout);

32	if(!$fp) {

33	return '';

34

} else {

35	stream_set_blocking($fp, $block);

36	stream_set_timeout($fp, $timeout);

37	@fwrite($fp, $out);

38	$status = stream_get_meta_data($fp);

39	if(!$status['timed_out']) {

40	while (!feof($fp)) {

41	if(($header = @fgets($fp)) && ($header == "\r\n" $header =="\n")) {

42

break;

43

}

44

}

45

46	$stop = false;

47	while(!feof($fp) && !$stop) {

48	$data = fread($fp, ($limit == 0 $limit > 8192 ? 8192 :$limit));

49	$return .= $data;

50	if($limit) {

51	$limit -= strlen($data);

52	$stop = $limit

53

}

54

}

55

}

56	@fclose($fp);

57	return $return;

58

}

59

}