Check TCP connectivity for many servers at once.
Usage: ./check_tcp [<options>...] <servers>...
-a=false: show all servers, including OK status
-q=false: quietly exit when no servers in cmdline
-t=1: timeout waiting for response
Download precompiled binary for amd64 from here: http://redin.info/files/prj/go/check_tcp/amd64/check_tcp