[RPi Utilities] #rpi

README.md

RPi Utilities

Get mac addresses:

ifconfig -a | grep HWaddr | tr -s " " | cut -d' ' -f5

Output:

b8:27:eb:34:53:7e //eth0
b8:27:eb:61:06:2b //wlan0

Get serial number:

awk '/Serial/{print $3}' /proc/cpuinfo

Output:

000000002b34537e

Notice that the last 6 characters of the serial number and the last 6 characters of the eth0 mac address are the same.

Python

def getserial():
    # Extract serial from cpuinfo file
    cpuserial = "0000000000000000"
    try:
        f = open('/proc/cpuinfo','r')
        for line in f:
            if line[0:6] == 'Serial':
                cpuserial = line[10:26]
        f.close()
    except:
        cpuserial = "ERROR000000000"

    return cpuserial

def getMAC(interface):
  # Return the MAC address of interface
  try:
    str = open('/sys/class/net/' + interface + '/address').read()
  except:
    str = "00:00:00:00:00:00"
  return str[0:17]

crontab

* * * * * /home/pi/CODE/cudp >> /home/pi/CODE/cudp.txt

cudp.go

package main

import (
    "fmt"
    "net"
    "time"
    "log"
    "strconv"
)

//CheckError ...
func CheckError(err error) {
    if err  != nil {
        fmt.Println("Error: " , err)
    }
}

func main() {
    ServerAddr,err := net.ResolveUDPAddr("udp","224.0.0.1:1234")
    LocalAddr, err := net.ResolveUDPAddr("udp", ":0")
    CheckError(err)

    Conn, err := net.ListenUDP("udp", LocalAddr)
    CheckError(err)

    defer Conn.Close()

    i := 0
    for {
        msg := strconv.Itoa(i)
        i++
        buf := []byte("request;23;/alive;" + msg)
        _,err := Conn.WriteTo(buf, ServerAddr)
        if err != nil {
            fmt.Println(msg, err)
        }
        time.Sleep(time.Second * 1)

        buf = make([]byte, 1024)
        n,addr,err := Conn.ReadFrom(buf)
        log.Println("Received ",string(buf[0:n]), " from ",addr)
    }
}