I am using ubuntu 17.10. After installing driver for USB wifi adapter. I still cannot see the usb wifi adapter.
$ lsusb
Bus 001 Device 004: ID 04f2:b52b Chicony Electronics Co., Ltd
Bus 001 Device 003: ID 13d3:3496 IMC Networks
Bus 001 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 006: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812AU
802.11a/b/g/n/ac WLAN Adapter
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
link/ether 10:7b:44:27:57:1a brd ff:ff:ff:ff:ff:ff
5: wlp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP
group default qlen 1000
link/ether 4a:f7:08:20:90:d2 brd ff:ff:ff:ff:ff:ff
inet 172.20.20.20/24 brd 172.20.20.255 scope global dynamic wlp1s0
valid_lft 248sec preferred_lft 248sec
inet6 fe80::c3e3:cefb:36eb:43d1/64 scope link
valid_lft forever preferred_lft forever
