g'day,
Could anybody help me with joinning data?
Below what I do....
Code:struct data { union { struct { u_int16_t match_size; char name[512]; u_int8_t revision; } user; u_int16_t match_size; } u; unsigned char data[0]; }; int main{ struct data *p=NULL, *m=NULL; p = foo();// here i add something to struct struct data m = oof();// and here too memcpy(p+sizeof(struct data),m,sizeof(struct data)); // it's not appending data from *m pointer to *p pointer, why? how that make? }
Did you actually allocate enough data for both structures?
Quzah.
Hope is the first step on the road to disappointment.
I guess yes, for just one it works well, but I can't add second.
and I add here size for second struct...
p+sizeof(struct data)
No. That's not allocating memory. That's assuming memory is there, and trying to access it.
Quzah.
Hope is the first step on the road to disappointment.
ok, but if I did that, I've got in *t only data from *p and lose data from *m.
how that make?Code:int main{ struct data *p=NULL, *m=NULL,*t=NULL; p = foo();// here i add something to struct struct data m = oof();// and here too t=calloc(1,sizeof(*p)+sizeof(*m)); memcpy(t,p,sizeof(*p)); memcpy(t+sizeof(*m),l,sizeof(*m)); }
Something like that perhaps.Code:struct data *p, *q, *r; p = foo(); /* allocates 1 instance of data, does whatever... */ q = bar(); /* ...same... */ r = realloc( p, 2 * sizeof *p ); if( r ) { memcpy( r + sizeof *r, q, sizeof *q ); free( q ); p = r; }
Quzah.
Hope is the first step on the road to disappointment.
