On Tue, Jun 5, 2018 at 11:11 PM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > On Tue, 05 Jun 2018 20:15:01 +1000, Chris Angelico wrote: > >> On Tue, Jun 5, 2018 at 5:37 PM, Steven D'Aprano >> <steve+comp.lang.pyt...@pearwood.info> wrote: >>> On Mon, 04 Jun 2018 22:13:47 +0200, Peter J. Holzer wrote: >>> >>>> On 2018-06-04 13:23:59 +0000, Steven D'Aprano wrote: >>> [...] >>> >>>>> I don't know whether or not the Linux OS is capable of accessing >>>>> files with embedded NULs in the file name. But Mac OS is capable of >>>>> doing so, so it should be possible. Wikipedia says: >>>>> >>>>> "HFS Plus mandates support for an escape sequence to allow arbitrary >>>>> Unicode. Users of older software might see the escape sequences >>>>> instead of the desired characters." >>>> >>>> I don't know about MacOS. In Linux there is no way to pass a filename >>>> with an embedded '\0' (or a '/' which is not path separator) between >>>> the kernel and user space. So if a filesystem contained such a >>>> filename, the kernel would have to map it (via an escape sequence or >>>> some other mechanism) to a different file name. Which of course means >>>> that - from the perspective of any user space process - the filename >>>> doesn't contain a '\0' or '/'. >>> >>> That's an invalid analogy. According to that analogy, Python strings >>> don't contain ASCII NULs, because you have to use an escape mechanism >>> to insert them: >>> >>> string = "Is this \0 not a NULL?" >>> >>> >>> But we know that Python strings are not NUL-terminated and can contain >>> NUL. It's just another character. >>> >>> >> No; by that analogy, a Python string cannot contain a non-Unicode >> character. Here's a challenge: create a Python string that contains a >> character that isn't part of the Universal Character Set. > > Huh? In what way is that the analogy being made? Your challenge is > impossible from pure Python, equivalent to "create a Python bytes object > that contains a byte greater than 255". The challenge is rigged to be > doomed to fail.
And an ASCIIZ string cannot contain a byte value of zero. The parallel is exact. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
