strange interaction between open and cwd

[Grant Edwards]

On 2010-05-03, Baz Walter <bazwal at ftml.net> wrote:
> On 03/05/10 14:18, Chris Rebert wrote:
>> Whether or not /home/baz/tmp/xxx/ exists, we know from the very
>> structure and properties of directory paths that its parent directory
>> is, *by definition*, /home/baz/tmp/ (just chop off everything after
>> the second-to-last slash). I would assume this is what happens
>> internally.
>> How exactly this interacts with, say, moving the directory to a new
>> location rather than deleting it, I don't know; again, it would quite
>> likely be platform-specific.
>
> but how does '..' get resolved in the relative path '../abc.txt'?

The current directory has an entry named '..' that points to the
parent directory.

> i'm assuming python must initially use getcwd() internally to do
> this,

Nope.  Python just passes the string '../abc.txt' to libc's open()
function, and that in turn passes it on to the Unix/Linux open()
syscall, when follows the link in the current working directory named
'..'.

> and then if that fails it falls back on something else. but what is
> that something else? is it something that is reproducible in pure
> python?

None of this has anything at all to do with Python.

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