supporting curl_file_create`

README.md

@@ -71,10 +71,12 @@ To upload files in a multipart form representation simply place an `@` symbol be
 ```php
 $response = Unirest::post("http://httpbin.org/post", array( "Accept" => "application/json" ),
   array(
-    "file" => "@/tmp/file.txt"
+    "file" => Unirest::file("/tmp/file.txt")
   )
 );
  ```
+
+ Use the value of `Unirest::file($path)` to assign a file to a parameter.
  
 ### Custom Entity Body
 Sending a custom body such as a JSON Object rather than a string or form style parameters we utilize json_encode for the body:

lib/Unirest/Unirest.php

@@ -113,6 +113,18 @@
 						return Unirest::request(HttpMethod::PATCH, $url, $body, $headers, $username, $password);
 				}
 
+				/**
+				 * Prepares a file for upload. To be used inside the parameters declaration for a request.
+				 * @param string $path The file path
+				 */
+				public static function file($path) {
+						if (function_exists("curl_file_create")) {
+								return curl_file_create($path);
+						} else {
+								return "@" . $path;
+						}
+				}
+
 				/**
          * This function is useful for serializing multidimensional arrays, and avoid getting
          * the "Array to string conversion" notice

test/Unirest/UnirestTest.php

@@ -94,7 +94,7 @@ class UnirestTest extends UnitTestCase
     $response = Unirest::post("http://httpbin.org/post", array( "Accept" => "application/json" ),
       array(
  "name" => "Mark",
-        "file" => "@" . dirname(__FILE__) . "/test_upload.txt"
+        "file" => Unirest::file(dirname(__FILE__) . "/test_upload.txt")
       )
     );
     $this->assertEqual(200, $response->code);