Amol Mohite wrote:
> say I have a char *c pointing to an array of 10 bytes.
>
> When i do (int *)c++ (increment before typecast -- forget the brackets for
> nw), and equate it t an int *i then
>
> *i will return 2nd to fifth bytes as integer. Is this correct ?
No. `(int *)++c' or `(int *)(c+1)' would do that. `(int *)c++' stores
the result before the increment occurs.
> And supose the typecase is beore the incerenent like so :
> ((int *)c)++ then *i will return 5th to 8th byes. is this correct ?
++((int *)c) will do that, but again `((int *)c)++' stores the result
before the increment occurs.
> aslo how is exception handling implemented ? Does the processor have
> exception registers ?
What sort of exception? Hardware exceptions (e.g. segfault) result in
the processor jumping to a defined location. The details depend upon
the particular type of processor.
> Also if I have allocated a struct liek :
>
> struct {
> int i;
> char b;
> }str;
>
> which is obviously 5 butes large.
1. The ANSI standard doesn't specify that `sizeof(int) == 4', so you
shouldn't assume that it is. If you want an integer of a specific
size, use the types from sys/types.h, e.g. int32_t.
2. It's 8 actually bytes on x86 using gcc. The structure is padded to
a whole number of words. If you wanted to pack the structure, use:
struct {
int i;
char b;
} __attribute__ ((packed)) str;
[NB: this is a gcc extension.]
--
Glynn Clements <[EMAIL PROTECTED]>
