Re: [boost] Re: [filesystem] new functions proposals

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-04-21 08:15:35

Jason House wrote:
> Vladimir Prus wrote:
> > Does those "alternate streams" belong to filesystem library at all?
> > For one thing, the ':' symbols is not allowed anywhere except for root
> > name. For another thing, on all systems but NTFS, "bar.baz.blip:blat"
> > would be considered as having "blip:blat" extension, and making the
> > function behave differently on NTFS is confusing. Lastly, the 'extension'
> > function is supposed to do only syntax transformation, but to tell if
> > you're on Fat32 or NFTS you'd need to ask operating system...
> >
> > - Volodya
>
> From the library standpoint, I would have to imagine that there should
> be some kind of support for appending :blat...
>
> In fact, you can even add a stream to a directory! c:\:hiddenfile.txt

It's hard to portably support unportable extension ;-) In fact, a seemingly
simple issue of finding file attributes (size, for example), is still not 
finally solved.

> Without any real usage information, I find it hard to say what the
> extrension truly is.  Maybe blip:blat really would be appropriate.  In
> most cases it would make the file extension unrecognized through code
> unaware of :blat...  But it does make me wonder if there is some way to
> make such a case more obvious to the application programmer...  The only
> file usage example I've seen actually did stuff like good.txt:bad.txt
> ... the used a new file extension in the stream name!  At the very
> least, this might break the "last period" rule for file extension...

Alas, I can't add more to this discussion. I don't know a bit about how 
alternate streams are used, and don't have the time to find out.
I think that basic, syntantic "extension" and "change_extension" are quite 
usefull anyway. 

Beman, if that's fine with you, I'll code them.

- Volodya