FileDirectory>>fileExists: (was: Re: [BUG]Unable to load BFAV, various problems )

Frank Shearar frank.shearar at rnid.org.uk
Mon Apr 26 09:06:15 UTC 2004


> >>> "goran.krampe at bluefish.se" 04/23/04 10:25 >>>
>
> Hi!
>
> Ned Konz <ned at bike-nomad.com> wrote:
> > These things are all trouble prone.
> >
> > Look at the kinds of things we do with filenames:
> >
> > * truncate change set names
> > * construct sequentially named files
> > * copy files between directories
> > * construct names for new files
> > * construct new directories (Squeaklets, etc.) with fixed names
>
> > * map filenames to file://URLs
> > * map file://URLs to filenames
>
> Just wanted to mention I dug into FileURL recently and that class
> FileUrl now has a class comment (Yay!) that has a few
> noteworthy things
> at the end. For example - the fact that a file URL *is always
> absolute*.
> It now also works much better.
>
> Things I discovered when doing this:
>
> 1. URI and URL are two different things and the RFCs are somewhat
> conflicting. :) I only tried to make FileURL as good as I could given
> the circumstances. Had some conversations on IRC with Ken on all this,
> quite confusing subject given that I looked at RFC2396 first and then
> RFC1738 etc. Bah.

In what ways do they differ? RFC 2396 updates RFC 1738, and RFC 2396 says
this:

<quote>
1.2. URI, URL, and URN

   A URI can be further classified as a locator, a name, or both.  The
   term "Uniform Resource Locator" (URL) refers to the subset of URI
   that identify resources via a representation of their primary access
   mechanism (e.g., their network "location"), rather than identifying
   the resource by name or by some other attribute(s) of that resource.
   The term "Uniform Resource Name" (URN) refers to the subset of URI
   that are required to remain globally unique and persistent even when
   the resource ceases to exist or becomes unavailable.
</quote>

That, to me, seems to say that URIs and URLs (and URNs) have identical
syntax, but differ only in meaning - a URI names something while a URL
provides an address for something. Or did you mean that when you said "URI
and URL are two different things"?

frank





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