What is the difference in the data that you receive?
On Monday, 18 July 2016 05:42:36 UTC+3, EdgarAlejandro Vintimilla wrote:
>
> now I have this, but still not the correct results
>
> package main
>
> import (
> "fmt"
> "net"
> "os"
> //"strconv"
> //"bytes"
> //"io/ioutil"
> //"net/http"
> "reflect"
> //"strings"
> )
>
> const (
> CONN_HOST = ""
> CONN_PORT = "5555"
> CONN_TYPE = "tcp"
> )
>
> func main() {
> // Listen for incoming connections.
> l, err := net.Listen(CONN_TYPE, CONN_HOST+":"+CONN_PORT)
> if err != nil {
> fmt.Println("Error listening:", err.Error())
> os.Exit(1)
> }
> // Close the listener when the application closes.
> defer l.Close()
> fmt.Println("Listening on " + CONN_HOST + ":" + CONN_PORT)
> for {
> // Listen for an incoming connection.
> conn, err := l.Accept()
> if err != nil {
> fmt.Println("Error accepting: ", err.Error())
> os.Exit(1)
> }
> // Handle connections in a new goroutine.
> go handleRequest(conn)
> }
> }
>
> // Handles incoming requests.
> func handleRequest(conn net.Conn) {
>
> // Make a buffer to hold incoming data.
> buf := make([]byte, 1024)
>
> // Read the incoming connection into the buffer.
> reqLen, err := conn.Read(buf)
> buf = buf[:reqLen]
>
> if err != nil {
> fmt.Println("Error reading:", err.Error())
> }
>
> var cadena string = ""
> for i := 0; i < len(buf)-1; i++ {
> cadena += fmt.Sprintf("%x ", buf[i])
> }
>
>
> // Send a response back to person contacting us.
> conn.Write([]byte( "ok" ))
> fmt.Println("cadena: ", cadena, reflect.TypeOf(cadena) )
> fmt.Println( "\n" )
>
> // Close the connection when you're done with it.
> conn.Close()
>
> }
>
>
>
> On Sunday, July 17, 2016 at 2:05:22 PM UTC-5, Egon wrote:
>>
>> On Sunday, 17 July 2016 21:42:26 UTC+3, EdgarAlejandro Vintimilla wrote:
>>>
>>> Hi, I have a GPS that sends me data through a connection TCP
>>>
>>> the data it sends me are in ASCII, and I have to convert it to HEX
>>>
>>> for example in python I'm doing this
>>>
>>> BUFFER_SIZE = 1024
>>> conn, addr = s.accept()
>>> data = conn.recv(BUFFER_SIZE)
>>> data.encode("hex")
>>> conn.close()
>>> print data
>>>
>>> and it works.
>>>
>>> but in GO,
>>>
>>> buf := make([]byte, 1024)
>>> reqLen, err := conn.Read(buf)
>>>
>>
>> Note, from here you are not using reqLen, you probably should do:
>> buf = buf[:reqLen], although if the conn is not fast enough you may not
>> receive the full request.
>>
>>
>>> if err != nil {
>>> fmt.Println("Error: ", err.Error())
>>> }
>>>
>>> fmt.Println("buf: ", buf)
>>> fmt.Println("buf str: ", string(buf))
>>>
>>
>> this []byte to string conversion assumes that "buf" is encoded as UTF8,
>> so if you have bytes that are larger than 0x7f you might get bizarre
>> results. *(Although I know you mentioned ASCII, it might also be
>> Extended ASCII)*
>>
>>
>>> var str string = ""
>>> for i:=0; i< len(buf); i++{
>>> str += strconv.FormatUint(uint64(buf[i]), 16)
>>> }
>>> fmt.Println("str: ", str)
>>>
>>> or if I use io, error2 :=ioutil.ReadAll(connection) i do not get the
>>> exact data that it sends me in any way
>>>
>>
>> data, err := ioutil.ReadAll(conn)
>> if err != nil { panic(err) }
>> enc := hex.EncodeToString(data)
>> fmt.Println("hex:", enc)
>>
>>
>> Also you should be probably reading up to the message sequence not
>> everything. Protocols usually define some ending character or sequence, or
>> have a leading length of message. I suspect you should read up-to a
>> line-feed instead of everything. And also that might be the reason that you
>> get different results from Go and Python.
>>
>> + Egon
>>
>
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