send.c

实现串口通讯文件收发的功能,在宿主机和目标机中用串口来来传送文件数据.

#include "unistd.h"
#include "fcntl.h"
#include "stdio.h"
#include "sys/types.h"
#include "errno.h"
#include "string.h"
#include     <sys/stat.h>   /**/
#include     <termios.h>    /*PPSIX终端控制定义*/


#define BUFFER_SIZE 64
#define FALSE 0
#define TRUE 1

/***@brief  设置串口通信速率
*@param  fd     类型 int  打开串口的文件句柄
*@param  speed  类型 int  串口速度
*@return  void*/

int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,
	    B38400, B19200, B9600, B4800, B2400, B1200, B300, };
int name_arr[] = {38400,  19200,  9600,  4800,  2400,  1200,  300,
	    38400,  19200,  9600, 4800, 2400, 1200,  300, };
void set_speed(int fd, int speed)
{
  int   i;
  int   status;
  struct termios   Opt;
  tcgetattr(fd, &Opt);
  for ( i= 0;  i < sizeof(speed_arr) / sizeof(int);  i++)
   {
   	if  (speed == name_arr[i])
   	{
   	    tcflush(fd, TCIOFLUSH);
    	cfsetispeed(&Opt, speed_arr[i]);
    	cfsetospeed(&Opt, speed_arr[i]);
    	status = tcsetattr(fd, TCSANOW, &Opt);
    	if  (status != 0)
            perror("tcsetattr fd1");
     	return;
     	}
   tcflush(fd,TCIOFLUSH);
   }
}
/**
*@brief   设置串口数据位，停止位和效验位
*@param  fd     类型  int  打开的串口文件句柄*
*@param  databits 类型  int 数据位   取值 为 7 或者8*
*@param  stopbits 类型  int 停止位   取值为 1 或者2*
*@param  parity  类型  int  效验类型 取值为N,E,O,,S
*/
int set_Parity(int fd,int databits,int stopbits,int parity)
{
	struct termios options;
 if  ( tcgetattr( fd,&options)  !=  0)
  {
  	perror("SetupSerial 1");
  	return(FALSE);
  }
  options.c_cflag &= ~CSIZE;
  switch (databits) /*设置数据位数*/
  {
  	case 7:
  		options.c_cflag |= CS7;
  		break;
  	case 8:
		options.c_cflag |= CS8;
		break;
	default:
		fprintf(stderr,"Unsupported data size\n");
		return (FALSE);
	}
  switch (parity)
  	{
  	case 'n':
	case 'N':
		options.c_cflag &= ~PARENB;   /* Clear parity enable */
		options.c_iflag &= ~INPCK;     /* Enable parity checking */
		break;
	case 'o':
	case 'O':
		options.c_cflag |= (PARODD | PARENB);  /* 设置为奇效验*/ 
		options.c_iflag |= INPCK;             /* Disnable parity checking */
		break;
	case 'e':
	case 'E':
		options.c_cflag |= PARENB;     /* Enable parity */
		options.c_cflag &= ~PARODD;   /* 转换为偶效验*/  
		options.c_iflag |= INPCK;       /* Disnable parity checking */
		break;
	case 'S':
	case 's':  /*as no parity*/
		options.c_cflag &= ~PARENB;
		options.c_cflag &= ~CSTOPB;
		break;
	default:
		fprintf(stderr,"Unsupported parity\n");
		return (FALSE);
		}
  /* 设置停止位*/   
  switch (stopbits)
  	{
  	case 1:
  		options.c_cflag &= ~CSTOPB;
		break;
	case 2:
		options.c_cflag |= CSTOPB;
		break;
	default:
		fprintf(stderr,"Unsupported stop bits\n");
		return (FALSE);
	}
  /* Set input parity option */
  if (parity != 'n')
  		options.c_iflag |= INPCK;
    options.c_cc[VTIME] = 150; // 15 seconds
    options.c_cc[VMIN] = 0;

  tcflush(fd,TCIFLUSH); /* Update the options and do it NOW */
  if (tcsetattr(fd,TCSANOW,&options) != 0)
  	{
  		perror("SetupSerial 3");
		return (FALSE);
	}
  return (TRUE);
 }
/**
*breif 打开串口
*/
int OpenDev(char *Dev)
{
int	fd = open( Dev, O_RDWR );         //| O_NOCTTY | O_NDELAY
	if (-1 == fd)
		{ /*设置数据位数*/
			perror("Can't Open Serial Port");
			return -1;
		}
	else
	return fd;

}

int main(int argc,char **argv)
{
  int from_fd,to_fd,i,j,total_bytes=0;
  int bytes_read,bytes_write;
  char buffer[BUFFER_SIZE];
  char *ptr;
  char *dev ="/dev/ttyS0"; //linux下的端口就是通过打开设备文件操作的
  to_fd = OpenDev(dev); //打开
  if (to_fd>0)
  {
    printf("to_fd open succeed\n");
    set_speed(to_fd,19200); //打开后设置波特率19200
    printf("speend is set\n");
  }
  else
  {
    printf("Can't Open Serial Port!\n");
    exit(0);
  }
  if (set_Parity(to_fd,8,1,'N')== FALSE) //设置8，1，n 注意，这里和上面要和下位机相符才可能通信
  {
    printf("Set Parity Error\n");
    exit(1);
  }
  printf("Parity is set\n");  


  if(argc!=2)
  {
    fprintf(stderr,"Usage: %s from file to /dev/ttyS0\n\a",argv[0]);
    exit(1);
  }
  /*open the scourse file*/
  if((from_fd=open(argv[1],O_RDONLY))==-1)
  {
    fprintf(stderr,"Open %s Error: %s\n",argv[1],strerror(errno));
    exit(1);
  }  

  i=0;
  while(bytes_read=read(from_fd,buffer,BUFFER_SIZE))
  {
    total_bytes += bytes_read;
    printf("in the %d read,we get %d bytes\n",++i,bytes_read);
    if((bytes_read==-1)&&(errno!=EINTR))
      break;
    else if(bytes_read>0)
         {
           ptr=buffer;
           j=0;
           while(bytes_write=write(to_fd,ptr,bytes_read))
           {
             printf("in this %d read cycle we write %d bytes in %d write\n",i,bytes_write,++j);
             if((bytes_write==-1)&&(errno!=EINTR))
                break;
             else if(bytes_write==bytes_read)
                    break;
             else if(bytes_write>0)
                  {
                     ptr+=bytes_write;
                     bytes_read-=bytes_write;
                  }
           }
           if(bytes_write==-1)
              break;
         }
  printf("input a key to continue...\n");
  getchar();   
  }
  printf("we send %d bytes all\n",total_bytes);
  close(from_fd);
  close(to_fd);
  exit(0);
}