Transfer file over ssh

Question

In ssh protocol, is there a mechanism for file transfer?
Im working on a existing code base which already has ssh facilities code. Now i need to transfer files over ssh connection. If ssh protocol already support it, i don't have to integrate scp stuff into it.

Thanks.

Edit:
Im using C, ssh code based on openssh.
I have to transfer the file programmingly, not using a external program/command because of some constraints. The program supposed to transfer any size file on remote host chunk-by-chunk, and process the chunk on-the-fly. Then the chunk data is discarded.

Answer 1

echo "hello" | ssh user@SSHHost "cat - > /tmp/file"

I juste read the file, pipe it in SSH, and write on the SSHHost server in the /tmp/file.

Answer 2

sftp and scp are both existing "secure" file transfer methods, but your answers are going to depend on what technology stack you are using for your application. You don't mention whether you're using C#, PHP or another language, or what kind of machine your app runs on. These things will have a big bearing on the answers you will get.