Thread: Using COM Ports to send files between two PCs

Hi, this my first time programming sth in Network. I do not have many ideas about this and since I do not have much time left, and I didn't understand well, I should seek your help.I have to use C to send a file to another PC, well COM port are useful but I didn't find how to refer to the adress of my destination. If someone explains it to me or giveme useful links.

I found this C / C++ / C++.NET : Base communication série rs232 (win32) - CodeS SourceS, but I dont know how to use it to send files; if we could use socket it was gonna be great but it is mentionned not to.

There are old MSDOS programs like XMODEM, that transfer files over a serial port (to modem to modem) to a serial port. Perhaps you can find information on the protocol that XMODEM uses.

Originally Posted by PrinceDamon

I found this C / C++ / C++.NET : Base communication série rs232 (win32) - CodeS SourceS, but I dont know how to use it to send files; if we could use socket it was gonna be great but it is mentionned not to.

You'd use Windows communications functions like:

Code:

CreateFile()   /* opens the com port */
ReadFile()     /* reads from the com port */
WriteFile()    /* writes to the com port */
CloseHandle()  /* closes the com port */

And here is a site I found by Google'ing.

Hi everybody, this project was really intersting since I learned hiw COM ports work, but unfortunetely I couldn't finish it because I started it very late.
The document https://www.google.dz/url?sa=t&rct=j...82001339,d.ZWU explains well how DATA is sent. Once this is understood, the rest is easy.
This code is the non connected transmission through COM ports. There is a program that helps test in PC that do not have COM ports by creating virtual ones("Configure Virtual Serial Port Driver").

Code:

/********************************************************
 * Transmission without controle nor restart if errors *
 *************************************Non connected **/
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <stdint.h>
#include "Headers.h"
/******************************************************************************
  send : prepares the info , then send it.
  entry : adr_src         : source address.
             adr_dest        : destination address.
             msg              :DATA to sent.
             lg_msg          :size of msg.
******************************************************************************/
void send(char* adr_src,char* adr_dest,char* msg,int lg_msg){
    int i;
    TRAME trame;//char Buf[100];


    sprintf(trame.Info,"%s",msg);
    for(i=0;i<6;i++) {
      trame.adr_dst[i]=adr_dest[i];
      trame.adr_src[i]=adr_src[i];}
      trame.lg_info=lg_msg;
      trame.Ctrl=TRANSFERT_DATA;
      trame.deb_trame=DEBUT_TRAME;
      trame.fin_trame=FIN_TRAME;
      trame.num_seq=num_seq;
      trame.Fcs=generer_controle(trame);
      vers_canal(&trame,sizeof(TRAME));
}
/******************************************************************************
  receive : reçeives the info.
  entry : adr_src         : source address.
             adr_dest        : destination address.
             msg              :DATA to sent.
  returns : size of msg received.
******************************************************************************/
int receive(char* adr_src, char* adr_dest, char* msg){
    int i;
    TRAME trame;//char Buf[100];


    if(de_canal(&trame,sizeof(TRAME))){
        //Construire_Trame_Reception(trame,Buf);
        sprintf(msg,"%s",trame.Info);


        for(i=0;i<6;i++) {
            if(trame.adr_src[i]!=adr_src[i]){
                printf("\ntrame recu d'une source differante (");
                for(i=0;i<5;i++) printf("%x:",trame.adr_src[i]);
                printf("%x)\n",trame.adr_src[5]);
                break;
            }
        }
        for(i=0;i<6;i++) {
            if(trame.adr_dst[i]!=adr_dest[i]){
                printf("\ntrame recu pour un destinataire differant (");
                for(i=0;i<5;i++) printf("%x:",trame.adr_dst[i]);
                printf("%x)\n",trame.adr_dst[5]);
                break;
            }
        }
    }
    else msg="";
    return trame.lg_info;
}
/******************************************************************************/