Hi,
Simon Urbanek wrote:
> Your proposed behavior is inconsistent, anyway. The purpose of
> dirname is to return parent directory of the entity represented by
> the pathname.
Mmmm, I don't think this is true:
> dirname("aaa/..")
[1] "aaa"
"aaa" is not the parent directory of "aaa/.."
Same here:
> dirname("/usr/./.")
[1] "/usr/."
> "/my/path" and "/my/path/" are equivalent as they both
> represent the directory "path" whose parent is "/my", therefore
> returning "/my/path" in either case is inconsistent with the purpose
> of this function. As of trailing slashes (independently of dirname),
> sadly, some programs exploit the equivalence of both representations
> by encoding meta-information in the representation, but this behavior
> is quite confusing and error-prone. You're free to add such special
> cases to your application, but there is no reason to add such
> confusion to R.
Note that Python's designers were not afraid to emancipate from Unix for
this particular case:
>>> import os.path
>>> os.path.dirname("aaa/..")
'aaa'
>>> os.path.dirname("aaa/../")
'aaa/..'
Also note that, if the goal was to mimic Unix behaviour, then why not
fully go for it, even for edge-cases:
R
----
> dirname("/")
[1] "/"
> basename("/")
[1] ""
Unix
----
[EMAIL PROTECTED]:~> dirname "/"
/
[EMAIL PROTECTED]:~> basename "/"
/
Just my 2 cents...
Cheers,
H.
>
> Cheers,
> Simon
>
>
>
>>>> Prof Brian Ripley wrote:
>>>>> These functions work as they should: did you not read the help page
>>>>> which explicitly tells you what happens in this case?
>>>>>
>>>>> The Unix originals work in the same way:
>>>>>
>>>>> gannet% dirname /my/path/
>>>>> /my
>>>>>
>>>>> Please DO study the R posting guide and do the homework requesting
>>>>> of you before posting.
>>>>>
>>>>> On Mon, 26 Mar 2007, cstrato wrote:
>>>>>
>>>>>> Dear all,
>>>>>>
>>>>>> I have already twice encountered a case which I consider a
>>>>>> limitation of
>>>>>> dirname() and basename().
>>>>>>
>>>>>> In my functions I have a parameter "outfile" which e.g. tells
>>>>>> where
>>>>>> a file
>>>>>> should be stored. Usually "outfile" is of the form:
>>>>>> oufile = "/my/path/myname.txt"
>>>>>>
>>>>>>> outfile <- "/my/path/myname.txt"
>>>>>>> dirname(outfile)
>>>>>> [1] "/my/path"
>>>>>>> basename(outfile)
>>>>>> [1] "myname.txt"
>>>>>>
>>>>>> However, in addition I want to be able to define the path only,
>>>>>> while
>>>>>> creating the name "myname.txt" automatically.
>>>>>> Sorrowly, I get the following:
>>>>>>
>>>>>>> outfile <- "/my/path/"
>>>>>>> dirname(outfile)
>>>>>> [1] "/my"
>>>>>>> basename(outfile)
>>>>>> [1] "path"
>>>>>>
>>>>>> It would be great if dirname() and basename() could recognize:
>>>>>> dirname("/my/path/") = /my/path/
>>>>>> basename(""/my/path/") = ""
>>>>>> i.e. they should be able to recognize a trailing "/".
>>>>> Not according to the documentation.
>>>>>
>>>>>> Best regards
>>>>>> Christian
>>>>>> _._._._._._._._._._._._._._._._
>>>>>> C.h.i.s.t.i.a.n S.t.r.a.t.o.w.a
>>>>>> V.i.e.n.n.a A.u.s.t.r.i.a
>>>>>> _._._._._._._._._._._._._._._._
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>>>
>>>
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>
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