tcping does a TCP connect to the given ip/port combination.
The user can specify a timeout in seconds.
This is useful in shell scripts running in firewalled environments.
Often SYNs are just being dropped by firewalls,
thus connection establishment will be retried several times
(for minutes) until a TCP timeout is reached.
With tcping it is possible to check first if the desired port
is reachable and then start connection establishment.
Author: Marc Kirchner <mail(at)marc(dash)kirchner(dot)de>
WWW: http://stud.fh-heilbronn.de/~kirchner/tcping/tcping.html
PR: 60301
Submitted by: Dryice Liu
d11936114f