Thread: Structures, Pointers and arrays

Hi everyone, i have the following problem:

I have a struct which is declared as:

Code:

typedef struct                                
{
    unsigned char src[6], dst[6];
    unsigned short type;            


} eth_hdr;

and i have a function,in which i would like to do something like this:

Code:

void ethernet_decap(unsigned char *eth_in, eth_hdr *hdr)
{
       hdr -> src = eth_in;
}

The 'eth_in' is not the same size as the other array, its a lot bigger, but i need to copy the first 6 elements of the array to the 'src' array.
I know its wrong, but you can see what i would like to point at.
And without using strcpy or giving values to that array by a 'for' cicle or something..I want to solve it by pointers and casting. Is that possible somehow?


Thanx

Code:

    char p,*ptr = &p;

    p=eth_in[0];
    src[0]=*ptr;
    p=eth_in[1];
    src[1]=*ptr;
    p=eth_in[2];
    src[2]=*ptr;
    p=eth_in[3];
    src[3]=*ptr;
    p=eth_in[4];
    src[4]=*ptr;
    p=eth_in[5];
    src[5]=*ptr;
    src[6]="\0";
/*with type casting*/
    p=(char)eth_in[i];
    src[i]=*ptr;

A loop would do the same thing.

Code:

for(i=0;i<strlen(src)-1;i++){
    p=eth_in[i];
    src[i]=*ptr;
}