[boost] Re: Any interest in a boost::glob() function?

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2004-09-27 14:52:17

> >>     fs::path const starting_directory(".");
> >>     std::list<fs::path> const matches =
> >>         boost::glob("../te?t/foo*bar", starting_directory);
> >
> > This look way too inefficient. Why would you want to copy list of
complex
> > objects? Iterator interface seems much better fit here.
>
> Hi, Gennadiy.
>
> Rich Johnson's original proposal was for
>
> class glob_iterator
>     : public filter_iterator<
>           glob_predicate<>,
>           filesystem::directory_iterator>
> struct glob_iterator {};
>
> Indeed, I've retained this, although I shoved it into namespace
> boost::detail.
>
> The problem is that this glob_iterator will iterate only over the contents
> of a single directory.

Why? Because of filesystem::directory_iterator? Use different implementation

> Moreover, good implementations of the system glob
> require that:
>
>    In order to have access to a pathname, this function requires
>    search permission on every component of a pathname except the last,
>    and read permission on each directory of any filename component
>    in @c pattern that contains a wild card.
>
> which means that you *shouldn't* use glob_iterator if the component does
> not contain wildcards.

Sorry. It's out of scope of my understanding. Maybe filesystem experts could
comment on that. Or you could rephrase it.

>  Would you be happy if I changed the interface to:
>
>     std::list<fs::path> matches;
>     boost::glob(matches, "../te?t/foo*bar", starting_directory);

It slightly better, but I still prefer iterator interface. What I am going
to do with above list? Most probably I a mgoing to iterate through it to do
somethins, or find simething. What if I only need first matching element? We
have several years expirience now with container/iterator alternatives. I
believe iterator interface is more natual here (and ultimately more
efficient).

> If not, could you expand further?
>
> Regards,
> Angus

Gennadiy.