multipart form data 的数据格式

<form action="/upload" enctype="multipart/form-data" method="post">
    Username: <input type="text" name="username">
    Password: <input type="password" name="password">
    File: <input type="file" name="file">
    <input type="submit">
</form>

Content-Type: multipart/form-data; boundary={boundary}\r\n

--{boundary}\r\n
Content-Disposition: form-data; name="username"\r\n
\r\n
Tom\r\n

--{boundary}\r\n
Content-Disposition: form-data; name="file"; filename="myfile.txt"\r\n
Content-Type: text/plain\r\n
Content-Transfer-Encoding: binary\r\n
\r\n
hello word\r\n

--{boundary}--\r\n

POST /upload HTTP/1.1
Host: 172.16.100.128:5000
Content-Length: 394 
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryLumpDpF3AwbRwRBn
Referer: http://172.16.100.128:5000/

------WebKitFormBoundaryUNZIuug9PIVmZWuw
Content-Disposition: form-data; name="username"

Tom
------WebKitFormBoundaryUNZIuug9PIVmZWuw
Content-Disposition: form-data; name="password"

passwd
------WebKitFormBoundaryUNZIuug9PIVmZWuw
Content-Disposition: form-data; name="file"; filename="myfile.txt"
Content-Type: text/plain

hello world
------WebKitFormBoundaryUNZIuug9PIVmZWuw--