PHP stream_context_create()作用和用法分析

创建并返回一个文本数据流并应用各种选项，可用于fopen(),file_get_contents()等过程的超时设置、代理服务器、请求方式、头信息设置的特殊过程。

• 函数原型：resource stream_context_create ([ array $options [, array $params ]] )

用法

1. 例子一

   <?php
       $opts = [
           'http' => [
               'method'=>"GET",
               'header'=>"Accept-language: en\r\n" .
               "Cookie: foo=bar\r\n"
           ]
       ];
       $context = stream_context_create($opts);
       $fp = fopen('//www.jjxhp.com', 'r', false, $context);
       fpassthru($fp);
       fclose($fp);
   ?>

2. 案例二

   <?php
       $opts = [ 
           'http' => [
               'method'=>"GET",
               'header'=>"Accept-language: en\r\n" .
               "Cookie: foo=bar\r\n"
           ]
       ];
       $context = stream_context_create($opts);
   
       //You would setup the header this way:
   
       $opts = [ 
           'http' => [
               'method'=>"GET",
               'header'=> [
                   "Accept-language: en",
                   "Cookie: foo=bar",
                   "Custom-Header: value"
               ]
           ]
       ];
       $context = stream_context_create($opts);
   ?>

3. 案例三

   <?php
       $opts = [
           'http' => [
               'proxy' => 'tcp://127.0.0.1:8080', 
               'request_fulluri' => true
           ]
       ];
       $context = stream_context_create($opts);
       $data = file_get_contents('//www.www.jjxhp', false, $context);
       echo $data;
   ?>

4. 案例四

   <?php
       function do_post_request($url, $postdata, $files = null)
       {
           $data = "";
           $boundary = "---------------------".substr(md5(rand(0,32000)), 0, 10);
           //Collect Postdata
           foreach($postdata as $key => $val)
           {
               $data .= "--$boundary\n";
               $data .= "Content-Disposition: form-data; name=\"".$key."\"\n\n".$val."\n";
           }
           $data .= "--$boundary\n";
           //Collect Filedata
           foreach($files as $key => $file)
           {
               $fileContents = file_get_contents($file['tmp_name']);
               $data .= "Content-Disposition: form-data; name=\"{$key}\"; filename=\"{$file['name']}\"\n";
               $data .= "Content-Type: image/jpeg\n";
               $data .= "Content-Transfer-Encoding: binary\n\n";
               $data .= $fileContents."\n";
               $data .= "--$boundary--\n";
           }
           $params = [
               'http' => [
                   'method' => 'POST',
                   'header' => 'Content-Type: multipart/form-data; boundary='.$boundary,
                   'content' => $data
               ]
           ];
           $ctx = stream_context_create($params);
           $fp = fopen($url, 'rb', false, $ctx);
           if (!$fp) {
               throw new Exception("Problem with $url, $php_errormsg");
           }
           $response = @stream_get_contents($fp);
           if ($response === false) {
               throw new Exception("Problem reading data from $url, $php_errormsg");
           }
           return $response;
       }
       //set data (in this example from post)
       //sample data
       $postdata = [
           'name' => $_POST['name'],
           'age'  => $_POST['age'],
           'sex'  => $_POST['sex']
       ];
       //sample image
       $files['image'] = $_FILES['image'];
       do_post_request("//www.jjxhp.com", $postdata, $files);
   ?>