RE: [boost] Re: candidate for library, "sysutils"

From: Craig Henderson (chenderson_at_[hidden])
Date: 2001-03-28 03:29:28

Oops, my small observation has opened a huge nest of nasties ;-)
My point was more the fact that these differences must be acknowledged -
not necessarily implemented - by a generic Boost solution. The
Boost.Sysutils or whatever you want to call it should be a generic
templated library which abstracts the implementation specific detail to
some kind of traits/policy class, but ultimately provide the library
user with a consistent, reliable and static interface regardless of
platform and compiler. Of course, the traits/policy bit will be
extremely implementation specific, but there is nothing wrong with that,
IMHO.

Cheers
Craig

-----Original Message-----
From: flameframe_at_[hidden] [mailto:flameframe_at_[hidden]]
Sent: 28 March 2001 08:21
To: boost_at_[hidden]
Subject: [boost] Re: candidate for library, "sysutils"

Just a few examples for different OS...
1. absolute file names:

                 host	volume	directories	base	ext	vers
                ------- ------- --------------- ------- ------- ------

 UNIX				/dir1/dir2/	file	.ext	
 DOS OS/2 NT		A:	\dir1\dir1\	file	.ext
 MAC			volume:	dir1:dir2:	file	.ext
 VMS		host::	volume:	[dir1.dir2]	file	.ext	;vers

2. relative file names:

 UNIX	file ./file     dir1/file   ./dir1/file ../../dir1/file
 DOS 	file .\file     dir1\file   .\dir1\file ..\..\dir1\file
 MAC	file            :dir1:file  :dir1:file  :::dir1:file 
 VMS	file []file     [.dir1]file [.dir1]file [--.dir1]file

3. allowed characters in dir/file name:
 UNIX		any except '/'.
 DOS OS/2 NT	any except most punctuations.
 MAC		any except ':'.
 VMS		only a-z, A-Z, 0-9, '-', '_' and '$'.

4. Some specifics:
 UNIX :
~	home directory of the current user.
~user	home directory of the specified user.

 VMS :
        [000000]	top directory of a volume, so
                        [000000.dir1] is equivalent to [dir1]

        [dir1.dir2]	directory as a path
        [dir1]dir2.dir	directory as a file

I believe it would be more appropriate to pass desired syntax as a 
parameter to dirname()/basename(), etc.

Regards,
Vitalij.
--- In boost_at_y..., Matt Austern <austern_at_r...> wrote:
> David Abrahams wrote:
> > 
> > The fun's not over yet, kids: MacOS likes ':'!!
> > 
> > -Dave
> > ----- Original Message -----
> > From: "Thomas Matelich" <sosedada_at_u...>
> > To: <boost_at_y...>
> > Sent: Tuesday, March 27, 2001 4:56 PM
> > Subject: Re: [boost] candidate for library, "sysutils"
> > 
> > > Craig Henderson wrote:
> > >
> > > > It must be taken into account during the design of such a 
library, the
> > > > differences between OSs. For example, UNIX '/' and MS '\'. The
> > > > description of the isabs() in the Python doc below 
reads "Return true if
> > > > path is an absolute pathname (begins with a slash)." This is 
true on
> > > > UNIX, but with MS absolute pathnames can begin with "C:\" 
or "\\" for a
> > > > UNC path.
> > >
> > > Just a quick note because people often forget, MS will 
accept '/' in your
> > > code.  All my dir stuff uses '/' exclusively, converting on the 
way in.
> > > Don't bother #ifdef'ing your logic, just the inputs.
> 
> And there are other OS's where it starts getting pretty hard 
> to have anything that looks like the Unix-ish directory/
> subdirectory model, and where defining a single directory
> separation character isn't good enough.  I'm thinking of VMS, 
> for example (which can be made to look sort of like DOS/Windows 
> if you squint hard enough), and of IBM mainframe OS's, like 
> VM/CMS.
> 
> The question isn't whether you can come up with a convention
> that supports everything, because the answer is that you 
> can't, but rather how much generality you want to support.
> 
> 			--Matt

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