ish2

Fast, lightweight CLI tool to check if a host supports HTTP/2 via ALPN.

Dependencies

Tested with OpenSSL 1.1.1d.
On Debian-based:
sudo apt install libssl-dev

Compiling

Use make. To skip certificate verification, compile with make noverify.

Usage

./ish2 host [port].
By default, port 443 is used.

For example:

$ ./ish2 www.google.com
www.google.com h2
$ ./ish2 www.github.com 443
www.github.com http/1.1

NOTE: this tool hangs when the server does not support HTTPS. The quickest workaround is to use timeout(1):

$ timeout 3 ./ish2 deaddomain.com