如何使用select实时监听串口通信？

[zl198183]

如题，想在实时监听2440板子的串口数据，不知道用select怎么写？

[用户 昵称]

try

  #include   <stdio.h>   
  #include   <string.h>   
  #include   <unistd.h>   
  #include   <fcntl.h>   
  #include   <errno.h>   
  #include   <termios.h>   
    
  #define   BAUDRATE   B115200   
    
  open_port(void)   
  {   
          int   fd,speed;   
          struct   termios   newtio;   
            
          fd   =   open("/dev/ttyS0",O_RDWR|O_NOCTTY|O_NDELAY);   
          if(fd==-1)   
          {   
                  perror("open_port:Unable   to   open   /dev/ttyS0");   
          }   
    
            
          tcgetattr(fd,&newtio);     
    
          bzero(&newtio,sizeof(newtio));   
          //setting   c_cflag   
          newtio.c_cflag   |=   (CLOCAL|CREAD);   
          newtio.c_cflag   &=~PARENB;   
          newtio.c_cflag   &=~PARODD;   
          newtio.c_cflag   &=~CSTOPB;   
          newtio.c_cflag   &=~CSIZE;     
          newtio.c_cflag   |=CS8;   
          newtio.c_oflag|=OPOST;   
          //setting   c_iflag   
          newtio.c_iflag   &=~(IXON|IXOFF|IXANY);   
                    
          cfsetispeed(&newtio,BAUDRATE);   
          cfsetospeed(&newtio,BAUDRATE);   
          printf("speed=%d\n",BAUDRATE);   
          tcflush(fd,   TCIFLUSH);   
          tcsetattr(fd,TCSANOW,&newtio);     
            
          return(fd);   
  }   
    
    
  main()   
  {   
          int   fd,n,i;   
          unsigned   char   buff[256];   
          fd   =   open_port();   
          while(1){   
          n   =   read(fd,buff,256);   
          if(n>0){   
          printf("n=%d\n",n);   
                          for(i=0;i<n;i++)   
                            printf("%02X:",buff[i]);   
                            //printf("%c",buff[i]);   
          printf("\n");   
          }   
          }   
          close(fd);   
  }   

[cceczjxy]

INT32 ReadComPort (INT32 ComPort, void *data, INT32 datalength)
{
INT32 retval = 0;

FD_ZERO (&fs_read);
FD_SET (fd[ComPort], &fs_read);
tv_timeout.tv_sec = 0;//TIMEOUT_SEC (datalength, GetBaudrate ());
tv_timeout.tv_usec = 150000;//TIMEOUT_USEC;

retval = select (fd[ComPort] + 1, &fs_read, NULL, NULL, &tv_timeout);
if (retval)
return (read (fd[ComPort], data, datalength));
else
return (-1);
}

[chinalxkid]

回复。。阅读 ！！！