That's a pretty vague set of requirements. We don't even know if what protocols are suitable (http, ftp, smb, etc.), or if the other user is local to your own network, or located on another networks over the internet. I'm not even sure why it needs to be a command line.
Ppl do not typically just accept some arbitrary file being dumped on their machine. Not unless it's just YOU trying to get a file moved from one machine to another. Do you have any more information that would help explain your intentions so we can narrow down exactly what is and isn't possible, practical, etc.? Are you trying to incorporate this into a batch file (which might explain the command line requirement)?