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From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-08-04 19:42:27

At 10:29 PM 8/3/2002, Alex Rosenberg wrote:

>on 8/3/02 12:12 PM, Beman Dawes at bdawes_at_[hidden] wrote:
>> The only thing that changes from system to system is the
>> path constructor. Even for cross-platform compilation, that would seem

>> better handled by macros rather than burdening all users with something
>> needed only by a tiny percentage of users.

>What if I want to parse POSIX and Windows and Mac OS paths all on the
>host (which may or may not be the same as any of those)?
>The portable generic format used doesn't support characters that are
>for some of those filesystems. '/' should be legal for FAT32, NTFS, etc,
>right? Both it and '\0' are for HFS+.

Uh, both Microsoft's docs and an actual probe program say that '/' is not
legal in an NTFS filename. It is, along with '\', a separator character on
that system. I don't know about the other systems, but it hardly matters;
names with embedded '/' characters won't be portable.

The point of the portable generic format isn't to be able to represent
every path that is valid on some operating system somewhere, rather it
allows paths to be represented only when they follow the grammar. Since
the end use is use a C string representation of the path as an argument to
some operating system function, it would be counter productive to allow a
'\0', since this isn't allowed in the middle of a C string.

>As noted in the code, there are some artifacts in path, one of which
>to be an intent to differentiate files and directories. As it stands, a
>ending with '/' results in a throw. I'd think it would simply result in
>path tagging itself speculatively as a directory.

Any differentiation between files and directories in the path code is
residue from a prior failed design. It just didn't work to try to keep
track of which the path was supposed to represent.

It might be OK to allow a trailing '/' in input, but I'd want to do an
analysis of the pros and cons first. As far as the actual internal rep is
concerned, it would have to be stripped off since operating systems take a
dim view of added characters.


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