How to memset() memory to a certain pattern instead of a single byte?

On OS X, one uses memset_pattern4( ) for this; I would expect other platforms to have similar APIs.

I don't know of a simple portable solution, other than just filling in the buffer with a loop (which is pretty darn simple).

An efficient way would be to cast the pointer to a pointer of the needed size in bytes (e.g. uint32_t for 4 bytes) and fill with integers. It's a little ugly though.

char buf[256] = { 0, };
uint32_t * p = (uint32_t *) buf, i;

for (i = 0; i < sizeof(buf) / sizeof(* p); i++) {
    p[i] = 0x11223344;
}

Not tested!