Connector would connect to the socket if SERVER is specified as localhost on Linux

On linux, if SERVER is set to 'localhost'(and not to 127.0.0.1 or anything else) C/C will default to socket connection even if the port is set, which is confusing and far not always the socket is where C/C has default value for it.
As a matter of fact, it maybe makes sense to force tcp/ip connection if port is specified, and socket is not. Looking at current documentation, this can be a better solution. TCPIP is said to be Windows only, and if socket is not specified, that's said it has to be tcp/ip connection