Knocker is a simple and easy to use TCP security port scanner written in C to analyze hosts and all of the different services started on them. It is available for Linux, FreeBSD, HP-UX, and Windows9x/2000/NT and it is licensed under the GNU General Public License GPL
0.8.031 Dec 2020 00:17
It fixes a huge bug that was causing the program to crash after the first launch. A nonblocking timeout of 1 second has been added for a port connection.