Thread: placing struct members into an array

Hi,

I am trying to place the members of a struct sequentially into an array so that I can send one byte at a time down a serial line, but I can see no way of pulling each individual member out to fill the array.

Code:

int array[10];
int i;

struct fillArray 
{    
    member1
    member2
    member3
} arrayFill;

for(i=0;i<=10;i++)
{
    //how do I get the data from the struct to fill this loop?
    array[i]
}

It has been suggested that I use a union type, but I don't know anything about this as I have never come across it before, and the web was not too helpful on this occasion.

Thanks
Dave

Its an array of chars and ints, no pointers involved, I will have a look at memcpy(), thanks

--dave

thanks for the link, I'll have a look at that

--dave

I have this code to transfer the contents of my struct into a char array:

Code:

#include <stdio.h>
#include <string.h>

struct msg_on_send
{
   char descriptor_msg[5];
   int  address;
   char space;
   char cmdmsg[5];
   char CR;
   char LF;
};

size_t serialize(unsigned char *dst, const struct msg_on_send *object)
{
   size_t i = 0;

   memcpy(&dst[i], &object->descriptor_msg, sizeof object->descriptor_msg);
   i += sizeof object->descriptor_msg;

   memcpy(&dst[i], &object->address, sizeof object->address);
   i += sizeof object->address;

   memcpy(&dst[i], &object->space, sizeof object->space);
   i += sizeof object->space;

   memcpy(&dst[i], &object->cmdmsg, sizeof object->cmdmsg);
   i += sizeof object->cmdmsg;

   return i;
}

void showbytes(const void *object, size_t size)
{
   const unsigned char *byte;
   for ( byte = object; size--; ++byte )
   {
      printf("%02X", *byte);
   }
   putchar('\n');
}

int main()
{
   int member;
   struct msg_on_send SendMsg_on[sizeof member] =
   {
         SendMsg_on.descriptor_msg = "$str_";
         SendMsg_on.address = 0x02;
         SendMsg_on.space = 0x20;
         SendMsg_on.cmdmsg = "op_en";
         SendMsg_on.CR = 0x0D;
         SendMsg_on.LF = 0x0A;
   };
   unsigned char buffer [ sizeof SendMsg_on[0] ];
   showbytes(buffer, serialize(buffer, by));
   
   system("PAUSE");    
   return 0;
}

In the original code this took a fixed array, is my modification of loading the struct members within main valid, if not, can you suggest what I could do instead?

--dave