Why should I press enter twice to send HTTP request in ncap/nmap?

Question

I need to set up a manual connection with a domain and send an HTTP request. Like this : https://nmap.org/ncat/guide/ncat-usage.html As it mentions I should hit enter twice. But all commands on CMD I have ever worked with were fine with one enter. Does anybody know the reason? Thanks.

Answer 1

Not quite clear what exactly you are asking but that seems to deal with how a raw http request should be formed

https://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4

A message consists of zero or more headers and then an empty line. (And then a request body if any is needed)

So you get

Zero or more Request Header lines separated with a [newline = ENTER key]
[a line with only a newline = ENTER key]

So zero headers newline and a line containing only a newline and then an empty body ==> A a minimal http request that consists of only two ENTER key strokes.