static int str_find (lua_State *L) {
size_t l1, l2;
const char *s = luaL_check_lstr(L, 1, &l1);
const char *p = luaL_check_lstr(L, 2, &l2);
long init = posrelat(luaL_opt_long(L, 3, 1), l1) - 1;
struct Capture cap;
luaL_arg_check(L, 0 <= init && (size_t)init <= l1, 3, "out of range");
if (lua_gettop(L) > 3 || /* extra argument? */
strpbrk(p, SPECIALS) == NULL) { /* or no special characters? */
const char *s2 = lmemfind(s+init, l1-init, p, l2);
if (s2) {
lua_pushnumber(L, s2-s+1);
lua_pushnumber(L, s2-s+l2);
return 2;
}
}
else {
int anchor = (*p == '^') ? (p++, 1) : 0;
const char *s1=s+init;
cap.src_end = s+l1;
do {
const char *res;
cap.level = 0;
if ((res=match(L, s1, p, &cap)) != NULL) {
lua_pushnumber(L, s1-s+1); /* start */
lua_pushnumber(L, res-s); /* end */
return push_captures(L, &cap) + 2;
}
} while (s1++<cap.src_end && !anchor);
}
lua_pushnil(L); /* not found */
return 1;
}
static int str_byte (lua_State *L) {
size_t l;
const char *s = luaL_check_lstr(L, 1, &l);
long pos = posrelat(luaL_opt_long(L, 2, 1), l);
luaL_arg_check(L, 0<pos && (size_t)pos<=l, 2, "out of range");
lua_pushnumber(L, (unsigned char)s[pos-1]);
return 1;
}
static int str_sub (lua_State *L) {
size_t l;
const char *s = luaL_check_lstr(L, 1, &l);
long start = posrelat(luaL_check_long(L, 2), l);
long end = posrelat(luaL_opt_long(L, 3, -1), l);
if (start < 1) start = 1;
if (end > (long)l) end = l;
if (start <= end)
lua_pushlstring(L, s+start-1, end-start+1);
else lua_pushstring(L, "");
return 1;
}
static int f_seek (lua_State *L) {
static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
static const char *const modenames[] = {"set", "cur", "end", NULL};
FILE *f = tofile(L, 1);
int op = luaL_findstring(luaL_opt_string(L, 2, "cur"), modenames);
long offset = luaL_opt_long(L, 3, 0);
luaL_arg_check(L, op != -1, 2, "invalid mode");
op = fseek(f, offset, mode[op]);
if (op)
return pushresult(L, 0); /* error */
else {
lua_pushnumber(L, ftell(f));
return 1;
}
}
static int io_seek (lua_State *L) {
static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
static const char *const modenames[] = {"set", "cur", "end", NULL};
IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
FILE *f;
int op;
long offset;
lua_pop(L, 1); /* remove upvalue */
f = getnonullfile(L, ctrl, 1);
op = luaL_findstring(luaL_opt_string(L, 2, "cur"), modenames);
offset = luaL_opt_long(L, 3, 0);
luaL_arg_check(L, op != -1, 2, "invalid mode");
op = fseek(f, offset, mode[op]);
if (op)
return pushresult(L, 0); /* error */
else {
lua_pushnumber(L, ftell(f));
return 1;
}
}
