The following works beautifully if x==y, but if they are inequal, I get a
memory leak... the leak seems a very minor one, and doesnt prevent the code
from 'working' fine, it just annoys me to have sloppy allocation... was
wondering if somebody could tell me how I might avoid it.

#include <stdlib.h>

typedef struct {
  int dummy;
  int dummy2;

int main() {
int i,x=500,y=500;
pt_stupid **bubba;

bubba = (pt_stupid **) malloc(y * sizeof(pt_stupid  *));
for(i=0;i<x;i++)
        bubba[i] = (pt_stupid *) malloc(x * sizeof(pt_stupid));

return 0;

--

Two observations:  First, you're not doing any frees at all.  That's
fine in this case, since the program ends and you're guaranteed that all
its memory will be reclaimed.  As such, I don't know how you're
concluding that memory _isn't_ getting reclaimed at the end of its
execution (which is I presume what you mean), since you haven't even
said what operating system you're running this under.

Second, the Subject says this is about a pointer to a pointer to a
pointer to a struct, but it's only a doubly-indirected pointer to a
struct, not a triply-indirected one.

--

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pt_stupid is now a new name for the type "pointer to struct { int dummy;
int dummy2; }". It is not clear that that is what you intended.

bubba is a pointer to a pointer to a pointer to a struct. It is not
clear that that is what you intended.

Better: bubba = malloc(y * sizeof *bubba);

Now check it worked.

Better: bubba[i] = malloc(x * sizeof *bubba[i]);

Now check it worked.

In general, use   p = malloc(numobjs * sizeof *p)  when calling malloc;
the casts are not necessary, don't buy you anything, can in some
circumstances cost you, and look bug-ugly in any case.

Now, as for your bug, it's in your loop.

should be

for(i=0;i<y;i++)

n'est-ce-pas? :-)

--

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C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R answers, C books, etc: http://users.powernet.co.uk/eton
--

Memory leak? Gosh you are lucky:) That code is insane, consider what
happens if x>y. What on Earth were you thinking. Of course it is always
possible to write insanely bad code but that is not an excuse for
deliberately doing so. And why should you expect the compiler to stop
you?

Francis Glassborow
I offer my sympathy and prayers to all those who are suffering
as a result of the events of September 11 2001.
--

Can't say much about the memory leak because you don't show where the
store is freed. However your loop will give undefined behaviour if x > y
because your first allocation (if it succeeds, which you should check)
provides storage for y pointers, but your loop goes round x times to set
up the pointers.

    Des Walker
--