** Summary **

normalize a file name


** Synopsis **

    :   '''file normalize''' ''name''


** Description **

Returns a unique normalised path representation for the file-system object
(file, directory, link, etc), whose string value can be used as a unique
identifier for it. A normalized path is an absolute path which has all '`../`',
'`./`' removed. Also it is one which is in the "standard" format for the native
platform.  On MacOS, Unix, this means the segments leading up to the path must
be free of symbolic links/aliases (but the very last path component may be a
symbolic link), and on Windows it also means we want the long form with that
form's case-dependence (which gives us a unique, case-dependent path). 

The one exception concerning the last link in the path is necessary, because
Tcl or the user may wish to operate on the actual symbolic link itself (for
example [file delete], [file rename], [file copy] are defined to operate on
symbolic links, not on the things that they point to). 


** See Also **

   [file]:   
   [file nativename]:   
   [file readlink]:   


** Bugs **

   [http://sourceforge.net/tracker/?func=detail&atid=110894&aid=1194458&group_id=10894%|%1194458]:   fixed in 8.4.11


** Forward Compatibility **

   [file forward compatibility]:   `[[file normalize]` emulation code taken from critcl.tcl, and added to the wiki in the hope that more people will use normalize, and move faster to 8.4 and later.  



** Volume-Relative Paths **

Windows has the concept of a current directory per drive, a concept it
inherited from DOS.  From a Command Prompt you can do:

======none
c:
cd \winnt
d:
type c:setup.log
======

and see setup.log from the current directory \winnt on drive c:.  It's an
obscure featrue, and it doesn't work in Windows Explorer.

Therefore, if the current working directory is `c:\winnt`,


======
file normalize c:setup.log
======

results in 

======
C:/WINDOWS/WindowsUpdate.log
======


Prior to Tcl version 8.4.5, `[[file normalize]` didn't handle volume relative
paths correctly:

======
file normalize c:a/b
======

resulted in `c:a/b` 

** File normalize and Windows folder junctions **

2013-01-08: All Tcl versions before 8.5.13, 8.6.0 have bugs with folder junctions, when the access rights are restricted [https://sourceforge.net/tracker/?func=detail&atid=110894&aid=3092089&group_id=10894%|%tcl-Bugs-3092089%|%], [https://sourceforge.net/tracker/?func=detail&atid=110894&aid=3587096&group_id=10894%|%tcl-Bugs-3587096%|%].
They are fixed in [https://core.tcl.tk/tcl/info/8a291bcb44%|%Tcl fossil Check-in 8a291bcb44%|%].

[HaO]: `file normalize` will resolve junctions of the Windows NTFS file system
and return the path without the junctions, if there is a component after the
junction.  This is specially helpful, if the junction has less access rights
than the direct way (which is the case for localized "program files" folders of
Windows Vista).  I took the habbit, to pass any files in system folders by
`file normalize` before accessing them.

*** Example ***

Create a folder '`C:\test2`' and a junction '`C:\test2_junction`' to it.

In a dos box with administrator rights:

======none
C:\Windows\system32> cd c:\
C:\> mkdir test2
C:\> mklink /j test2_junction test2
======

Now test `file normalize` in a wish console:


======tcl
% file normalize c:/test2_junction
c:/test2_junction
% file normalize c:/test2_junction/test.txt
c:/test2/test.txt
======


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