[shanemhansen]

You don't do a HTTPS handshake by hand. That's what openssl s_client is for.

https://docs.openssl.org/1.0.2/man1/s_client/

Or maybe socat, I don't use it but I'm pretty sure I've seen people use it.

[charcircuit]

You are proving my point that telnet is not useful in modern times.

[abalashov]

Only if you're a web economy weenie and think HTTP[S] is the measure of utility of most TCP interactions. ;)

I can't remember the last time I used telnet to test whether a web server was live. I don't think web servers figure very prominently in the work I do, though not zero, for sure. However, I doubt I'm the only one in that boat.

[charcircuit]

Okay let's say you want to ping a Minecraft server and see how many users are online. That's not possible either with telnet.

The concept of protocols made up of printable characters delimited by new lines is antiquated.

[abalashov]

But that's not what I want to do. I just want to know if the listening socket is bound.

[LambdaComplex]

Alright, let's say you try doing that but it fails for some reason. Where did the failure occur? Were you able to open a TCP connection but you received garbage data that your minecraft-ping command didn't understand? Were you able to open a TCP connection but you received no reply to your ping? Did you fail to open a TCP connection (no SYNACK in response to your SYN)?

All of those problems have different root causes and therefore have different solutions. Telnet helps you figure out where in the stack the failure is occurring.