Programming

int cClassSerialLIB::ReadPort(/*QChar * Response*/)
{
     long int iIn;

     counter_uart2 =0;

     for (int i=0;i<6000;i++)
         array_uart2[i]='\0';

     
       if (fd < 1)
       {
           printf(" port is not open\n");
           return -1;
       } 

       iIn = read(fd, array_uart2, sizeof(array_uart2));

       static int count=0;

       if (iIn < 0)
       {
           if (errno == EAGAIN)
           {         
                   //qDebug("Read nothing");
                   return 0; // assume that command generated no response
           }
           else
           {
                   printf("read error %d %s\n", errno, strerror(errno));
           } 
       }

       counter_uart2=iIn;
       return iIn;
}

bool cClassSerialLIB::OpenPort(bool bloccante)
{
      // make sure port is closed
      ClosePort();
      //ttymxc4
      QByteArray Porta_byte_array = Porta.toLatin1();
      const char* Porta_char=Porta_byte_array.data();
      fd = open(Porta_char/*"/dev/ttymxc4"*/, O_RDWR |
                          O_NOCTTY | /* tells UNIX that this program doesn't want to be the "controlling terminal" for that port*/
                          O_NDELAY); /* tells UNIX that this program doesn't care what state the DCD signal line is in */

      if (fd < 0)
      {
          qDebug("errore in apertura %d %s\n", errno, strerror(errno));
          return false;
      }
      else
      {
          qDebug("ok %d",fd);
          struct termios options;

          /* The FNDELAY option causes the read function to return 0 if no
            characters are available on the port. To restore normal (blocking) behavior,
            call fcntl() without the FNDELAY option: */

          if(bloccante)
          {
              printf("bloccante\n");
              fcntl(fd, F_SETFL, 0);
          }
          else
          {
             printf("NON bloccante");
             fcntl(fd, F_SETFL, FNDELAY);
          }

          //cfmakeraw(&options); //ABILITARLO NEL CASO DI ERRORE!


          tcgetattr(fd, &options);

          //set port speed 115200
          cfsetispeed(&options, B115200);
          cfsetospeed(&options, B115200);

          options.c_cflag |= (CLOCAL | CREAD);

          //set 8n1

          options.c_cflag &= ~PARENB; /* Enable parity bit */
          options.c_cflag &= ~CSTOPB; /* 2 stop bits (1 otherwise) */
          options.c_cflag &= ~CSIZE; /* Mask the character size bits */
          options.c_cflag |= CS8; /* Select 8 data bits */

          options.c_iflag &= ~IXON; //RIMUOVE X0N/XOFF control
          options.c_iflag &= ~IXOFF;
          options.c_iflag &= ~IGNCR;

          //set raw input
          options.c_lflag &= ~(ICANON |   /*Enable canonical input (else raw)*/
                                  ECHO |  /*Enable echoing of input characters*/
                                  ECHOE | /*Echo erase character as BS-SP-BS*/
                                  ISIG);  /*Enable SIGINTR, SIGSUSP, SIGDSUSP, and SIGQUIT signals*/


          tcsetattr(fd, TCSANOW, &options); /*Make changes now without waiting for data to complete*/

      }
      return true;
}

man netcat

man nc

int cClassSerialLIB::ReadPort_poll(){
 
    int iIn;
    struct pollfd pfds[5];
 
    pfds[0].fd     = fd;
    pfds[0].events = POLLIN;
    int nfds = 1;
 
    while(1){
        /* poll aspetta indefinitivamente (-1) */
        int pollret = poll(pfds, nfds, -1);
 
        if (pollret == -1) {
           //perror("poll");
           continue;
        }
 
        /* 2) timeout: this should never happen really... */
        if (pollret == 0) {
 
           continue;
        }
 
        if(pfds[0].revents == POLLIN){
               iIn = read(fd, array_uart2, sizeof(array_uart2));
               if (iIn < 0)
               {
                   if (errno == EAGAIN)
                   {
                           continue; // assume that command generated no response
                   }
                   else
                   {
                           printf("read error %d %s\n", errno, strerror(errno));
                   } // end if
               }
 
               aggiorna1();
        }
    }
}

if(system_function() != 0)
{
        perror("system_function didn't work right");
}