Question: From what I had read sometime back, it seems `iwconfig` is deprecated and the current methods is - 

```
$ sudo ifconfig wlan0 up

```

and

```
$ sudo ifconfig wlan0 down

```

But couldn't find anything which tells the status of the wifi and know which mode it is on, which AP it is attached to, how much data is being transferred and so on and so forth on the CLI.

Answer: 
The current (in 2017) methods are:

1. `ip` for all network interfaces, including setting up and down:

```
ip link set wlan0 up
ip link set wlan0 down
ip help
ip link help
ip addr help

```
2. `iw` for wireless extensions (needs to be called as root):

```
iw dev
iw phy
iw wlan0 scan
iw wlan0 station dump
iw help

```

`ifconfig` and `iwconfig` are still supported with the appropriate packages, but some features are only available with `ip` and `iw`.
The [`net-tools`](https://wiki.linuxfoundation.org/networking/net-tools) program is deprecated and the `iproute2` has been used to replace it :

```
program     obsoleted by
arp         ip neigh
ifconfig    ip addr
ipmaddr     ip maddr
iptunnel    ip tunnel
route       ip route
nameif      ifrename
mii-tool    ethtool

```

The `ip show` will display the state of your network interface.

in addition there are some others tools will help you to get the state of your network interface :

```
cat /sys/class/net/<interface>/carrier

```

sample output:

```
1

```

the `1` mean your interface is `up` and `0` is down.

Or simply you can use the following command :

```
cat /sys/class/net/<interface>/operstate

```

sample output:

```
UP

```

or

```
DOWN

```