static int str_replace(lua_State *L) {
size_t l1, l2, l3;
const char *src = luaL_checklstring(L, 1, &l1);
const char *p = luaL_checklstring(L, 2, &l2);
const char *p2 = luaL_checklstring(L, 3, &l3);
int init = luaL_optinteger(L, 4, 1) - 1;
const char *s2;
int n = 0;
TBuffer b;
buffer_init (&b, l1, L);
if (init > 0) {
buffer_addlstring(&b, src, init);
}
while (1) {
s2 = lmemfind(src+init, l1-init, p, l2);
if (s2) {
buffer_addlstring(&b, src+init, s2-(src+init));
buffer_addlstring(&b, p2, l3);
init = init + (s2-(src+init)) + l2;
n++;
} else {
buffer_addlstring(&b, src+init, l1-init);
break;
}
}
buffer_pushresult(&b);
buffer_free (&b);
lua_pushnumber(L, (lua_Number)n); /* number of substitutions */
return 2;
}
void bufferZ_addlstring (TBuffer *buf, const void *src, size_t len) {
int n;
size_t header[2] = { ID_STRING };
header[1] = len;
buffer_addlstring (buf, header, sizeof (header));
buffer_addlstring (buf, src, len);
n = len % N_ALIGN;
if (n) buffer_addlstring (buf, NULL, N_ALIGN - n);
}
void bufferZ_addnum (TBuffer *buf, size_t num) {
size_t header[2] = { ID_NUMBER };
header[1] = num;
buffer_addlstring (buf, header, sizeof (header));
}
void buffer_addvalue (TBuffer *buf, int stackpos) {
size_t len;
const char *p = lua_tolstring (buf->L, stackpos, &len);
buffer_addlstring (buf, p, len);
}
void buffer_addbuffer (TBuffer *trg, TBuffer *src) {
buffer_addlstring (trg, src->arr, src->top);
}
