Comment by pilif | Hacker News Reader

Comment by pilif | Hacker News Reader

Parent Full thread

High Sierra has also removed telnet which is useful not for unencrypted access to remote shells, but for quick testing of TCP port availability at remote end. Yes. There’s nc to do the same thing, but then there is also muscle-memory built since the mid 90ies

On the other hand, I get where Apple is coming from: those two tools are decades old and pretty much unmaintained. By not shipping them by default, they can reduce the attack surface (code not shipped won’t have vulnerabilities)

If you need command line FTP and telnet access, you can of course use homebrew to get them back.

You technically don't even need any external commands to check if a remote port it open since bash itself can open raw tcp/udp connections.

    $ timeout 5 bash -c 'cat </dev/null >/dev/tcp/google.com/80' && echo "Open" || echo "Closed"

It does include netcat (nc) though, which can be used for testing ports, among other things.

ln -s /usr/bin/nc /yourpath/bin/telnet

The command-line options are the same.

Don't do this. Contrary to popular belief, telnet is a protocol beyond simply opening a bidirectional pipe over a socket. There are negotiation steps and the like.

Just install telnet if you need it. It's not like Apple actually wrote these apps anyway. Install them trivially with brew, telnet, ftp, whatever old garbage you need.

Funny thing is I just BARELY needed to install telnet. Well, "needed." I wanted to relive some old BBS memories.

You technically don't even need any external commands to check if a remote port it open since bash itself can open raw tcp/udp connections.

    $ timeout 5 bash -c 'cat </dev/null >/dev/tcp/google.com/80' && echo "Open" || echo "Closed"

Reply on news.ycombinator.com