func showUsage() {
	fmt.Println("usage: ./program 'DEVICE' 'TCP_PORT' 'HEADER' ")
	fmt.Println("example: ./program 'eth0' '2222' 'DNS_Session' ")
	fmt.Println("here's a list of interfaces :")
	fmt.Println(execShellCommand(`ifconfig -a | sed 's/[ \t].*//;/^\(lo\|\)$/d'`))
	fmt.Println("here's a list of tcp ports :")
	fmt.Println(execShellCommand(`netstat -pnl`))
	log.Fatal()
}
// show helper on how to use this client
show helper on how to use this client
// show helper on how to use this client
func showUsage() {
	fmt.Println("usage: ./program 'DEVICE' 'TCP_PORT' 'HEADER' ")
	fmt.Println("example: ./program 'eth0' '2222' 'DNS_Session' ")
	fmt.Println("here's a list of interfaces :")
	fmt.Println(execShellCommand(`ifconfig -a | sed 's/[ \t].*//;/^\(lo\|\)$/d'`))
	fmt.Println("here's a list of tcp ports :")
	fmt.Println(execShellCommand(`netstat -pnl`))
	log.Fatal()
}
func showUsage ( ) { fmt . Println ( " " ) fmt . Println ( " " ) fmt . Println ( " " ) fmt . Println ( execShellCommand ( `ifconfig -a | sed 's/[ \t].*//;/^\(lo\|\)$/d'` ) ) fmt . Println ( " " ) fmt . Println ( execShellCommand ( `netstat -pnl` ) ) log . Fatal ( ) }
show helper on how to use this client
show helper on how to use this client