linux wirless commands

Reference:
http://www.enterprisenetworkingplanet.com/netsecur/article.php/3594946
http://wirelessdefence.org/Contents/LinuxWirelessCommands.htm


Key folders:
/etc/wpa_supplicant/[wpa_supplicant.conf]
/etc/sysconfig/network-scripts/[ifcfg-eth0,ifcfg-wlan0]