I need to write a shell script which connects to one of the two available wi-fi connections. One is a un secure connection and the other is secure connection. My question has 2 parts-

1.How to connect to the un-secure (un-encrypted and no password required) connection from command line (or by executing a shell script) when I'm connected to the secure connection?

I followed the steps in http://www.ubuntugeek.com/how-to-troubleshoot-wireless-network-connection-in-ubuntu.html for in-secure connection. I put all the commands in a script and executed it (I made sure that interface name and essid are correct)

- sudo dhclient -r wlan0
- sudo ifconfig wlan0 up
- sudo iwconfig wlan0 essid "UAPublic"
- sudo iwconfig wlan0 mode Managed
- sudo dhclient wlan0

But nothing happens - I'm not disconnected from the current network and connected to the new one

2.When I want to connect to the secure wi-fi network, I understand from http://askubuntu.com/a/138476/70665 that I need to use wpa_supplicant. But I enter a lot of details in the interface when I connect via UI

• security : wpa and wpa2 enterprise
• Authentication : PEAP
• CA certificate : Equifax...
• PEAP version : automatic
• inner authentication : MSCHAPv2
• username :
• password :

How to use wpa_supplicant to mention all these details in the command line? The conf file network={ ssid="ssid_name" psk="password" } doesn't work for me.