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Subject: Re: Please define "canonicalize" in httpd.h
From: John Rowe <rowe@excc.ex.ac.uk>
To: dev@httpd.apache.org
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Date: Mon, 26 Jul 2004 14:51:25 +0100
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> Please define "canonicalize" 

If the same thing can be referred to by a number of different names and
the convention is that one is the "one true", or canonical, name and the
others are mere aliases then canonicalisation (or canonicalization for a
non-Brit) is the process of translating a name into the canonical name
of that object. Of course this assumes that no two objects can have the
same name.

In the context of case-insensitive file systems, it's often the case
that a file is given the canonical name that it was created with
("MyFile") with all other capitalisations ("myfile", "myfilE") being
alternative names for the same filename. 

Of course, the situation is complicated not only by symlinks but also
that in unix the same file can have many filenames. The normal
canonicalisation for a file, as opposed to filename, is (device, inode
number) but that's not always very useful: for security reasons you
can't actually open a file from its device and inode number.

John