writing data to a socket that is sent in 2 frames

Question

My appliactions sends through the wire using socket small messages. Each message is around 200 bytes of data. I would like to see my data sent in 2 frames instead of 1. My questions are

1. How to do that i.e. is there a way to cause TCP to automatically split the buffer in 2 frames?
2. Do I get the same if I send my buffer in 2 separate writes?

I am using Linux and C.

Answer 1

How to do that i.e. is there a way to cause TCP to automatically split the buffer in 2 frames?

TCP is a stream communication protocol, all data is continuous. You should split your data by delimiters.

For example, in HTTP protocol each separated request is splited by two \n.

Do I get the same if I send my buffer in 2 separate writes?

No, you will receive them as a one continuous data stream. Frames are meaningless.

Note: Before you receive any data TCP in your application, packets are separated but OS collect and reassemble them. This process is transparent from your application.