How can I find the name of my Network Interface

I have a project that requires me to scan the local network.

I found a program on the internet that allows the local network scanner condition, but I brought the gold @ IP argument in my network program must be turned the machine alone after two minutes.

So I determined a program from my PC IP and mask can give me the class CIDR (192.168.1.123/24), but to find this result I have to give the name of the network interface that my pc is connected (ie: wlan0, eth0 or eth1) to.

Q: Is there a method to find the name of the interface without the whole list as ifconfig does?