Function luaO_pushvfstring

third-party/lua-5.2.4/src/lobject.c:179–230

this function handles only `%d', `%c', %f, %p, and `%s' formats */

/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  int n = 0;
  for (;;) {
    const char *e = strchr(fmt, '%');
    if (e == NULL) break;
    luaD_checkstack(L, 2);  /* fmt + item */
    pushstr(L, fmt, e - fmt);
    switch (*(e+1)) {
      case 's': {
        const char *s = va_arg(argp, char *);
        if (s == NULL) s = "(null)";
        pushstr(L, s, strlen(s));
        break;
      }
      case 'c': {
        char buff;
        buff = cast(char, va_arg(argp, int));
        pushstr(L, &buff, 1);
        break;
      }
      case 'd': {
        setnvalue(L->top++, cast_num(va_arg(argp, int)));
        break;
      }
      case 'f': {
        setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
        break;
      }
      case 'p': {
        char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
        int l = sprintf(buff, "%p", va_arg(argp, void *));
        pushstr(L, buff, l);
        break;
      }
      case '%': {
        pushstr(L, "%", 1);
        break;
      }
      default: {
        luaG_runerror(L,
            "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
            *(e + 1));
      }
    }
    n += 2;
    fmt = e+2;
  }
  luaD_checkstack(L, 1);
  pushstr(L, fmt, strlen(fmt));
  if (n > 0) luaV_concat(L, n + 1);
  return svalue(L->top - 1);
}


const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {