做串口作业，按字符传输数据写的一个函数

指针操作！！！！！！
很关键！！！！


怎样让下位机知道上位机传输的一个结构数据？？
把结构数据转化为字符传输后，下位机再用同样的结构进行接收！！

受启发http://blog.chinaunix.net/u2/63775/showart_503546.html

关键代码：

/*按字符copy ,用到指针类型转换，结构struct知识,一开始use strcpy(),but the fuction working style is finished //by '\0' ,so can't use. i write a function use the parameter length,and pointer*/

static char * copy_by_char(char * dest,const char *src,int length)
{
    char *return_ptr=dest;
    for (int i=0; i<length; i++)
    {
     *dest++ = *src++;
    }
    return return_ptr;

}

源代码：

#include<iostream>

#include<stdlib.h>

using namespace std;

//按字符copy ,用到指针类型转换，结构struct知识,一开始use strcpy(),but the fuction working style is finished //by '\0' ,so can't use. i write a function use the parameter length,and pointer

static char * copy_by_char(char * dest,const char *src,int length)
{
    char *return_ptr=dest;
    for (int i=0; i<length; i++)
    {
     *dest++ = *src++;
    }
    return return_ptr;

}

int main(int argc,char **argv)
{

    char str1_array[256];
    int str2_array[256];
    

    char *string="communisim==commwealism";
    
    struct my_struct
    {
        int a;
        int b;
     char c;
    };
    



    struct my_struct A,B;
    A.a=1;A.b=2;A.c='Y';
    char *p1=(char *)&A;
    char *p2=(char *)&B;
    cout<<"A: length--"<<sizeof(A)<<endl;

    copy_by_char( p2, p1, sizeof(A));    //call function


    cout<<"B: length-----------"<<sizeof(B)<<endl;
    cout<<"A "<<"A.a = "<<A.a<<" A.b = "<<A.b<<endl;
    cout<<"B "<<"B.a = "<<B.a<<" B.b = "<<B.b<<" B.c = "<<B.c<<endl;
    /*
    *string to char array
    *
    */
    copy_by_char( str1_array, string,5);
    str1_array[5]='\0';

        //strcpy(str,(char *)&A);

    //str[6]='a';str[7]='\0';

    
    cout<<str1_array<<endl;//show array str1


    /*
    *struct to int array
    *
    */
    
    copy_by_char( (char *)str2_array, p1, 8);//copy A.a,A.b


    cout<<"str2_array[1] ="<<str2_array[1]<<endl;//show array str1

    

  return 0;

}

out put:

root@qing-laptop:~/programe# ./hello
A: length--12
B: length-----------12
A A.a = 1 A.b = 2
B B.a = 1 B.b = 2 B.c = Y
commu
str2_array[1] =2