Tcpdump/ngrep sniff packet network command lines
 

Hello everyone,
I would like to know the command lines for;
-detecting the wifi in my house without being connected to it
-getting ips/macaddress from the people connected to the wifi

You can't, that's not what the tools are for. libpcap based programs watch actual network traffic, not wireless radio data. You can't detect wifi with them. In terms of getting macs and the likes then if you have a system on the same network then you can just watch the netwrok traffic and see the mac addresses of any traffic addressed to you but on wifi, like a switch (as opposed to a hub) you will only see the traffic addressed to you / from you, not other users doing other things.

If I read the question the way it's written, the answer is:

Seriously, though, I know what you mean. Look into Kismet.