On 2023-08-18 07:09, Martin Wege via Cygwin wrote:
On Fri, Aug 18, 2023 at 10:44 AM Corinna Vinschen via Cygwin
<cygwin@cygwin.com> wrote:
On Aug 17 20:49, Martin Wege via Cygwin wrote:
On Mon, Aug 14, 2023 at 10:56 PM Corinna Vinschen via Cygwin
<cygwin@cygwin.com> wrote:
and the result is the same. Note that Cygwin supports MSFT NFSv3 but
not CITI NFSv4.1 internally. No gurantee that Cygwin always does what
is necessary for that other NFS.
1. How does Cygwin detect whether something is a MSFT NFSv3, or not?
Cygwin /bin/mount lists the CITI NFSv4.1 as 'nfs', so there *IS*
something which detects that?
The filesystem name returned by NtQueryVolumeInformationFile is "NFS".
If any other NFS returns the same filesystem name, it will be treated
just like MSFT NFSv3.
2. Are Cygwin soft link handing depend on MSFT NFSv3 or not, i.e. does
the Cygwin soft link code behave differently for MSFT NFSv3 file
systems?
Yes. NFS doesn't support symlink creation and symlink reading via
the usual functions, because Windows symlinks are created as reparse
points. NFS doesn't support reparse points. So the developers of
the MSFT NFS client had to invent their own way to create and
read NFS symlinks:
https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/path.cc;hb=HEAD#l1719
https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/path.cc;hb=HEAD#l2750
3. Does Cygwin implement the pathconf() api?
Yes. Surprisingly, you can check this yourself by just calling the
function and trying to compile your code.
Apologies, how do we say in German? "Ich sollte meine Frage konkretisieren:"
Does the Cygwin implementation of pathconf() support query data of the
underlying filesystem based on data from the kernel, as UNIX does? So
pathconf() returns different values for NTFS, ReFS, or Windows builtin
NFSv3?
I am asking, because as far as I know the Linux implementation is not
a syscall, and instead glibc guesses values based on builtin static
data, and whatever fstatfs() has to offer. Compared to that UNIX
(Solaris, AIX, HPUX, ...) have pathconf() as a syscall, and actually
ask the filesystem itself.
Many library functions are implemented as documented either in the Cygwin
packages cygwin-doc and man-pages-posix available for installation; and use as
e.g. `man 3p fpathconf`, also available online at:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fpathconf.html or
https://man7.org/linux/man-pages/man3/fpathconf.3p.html
and for comparison and reference we make Cygwin package man-pages-linux
available for installation; and use as e.g. `man -m linux 3 fpathconf`, also
available online at:
https://man7.org/linux/man-pages/man3/fpathconf.3.html
suggestions for setup are in the package announcements made every 9-12 weeks
when the latest Linux man-pages package is released and updated on Cygwin.
Please also note that the getconf(1) program is installed as part of Cygwin and
can access f/pathconf variables associated with a pathname argument, as shown in
getconf(1) `man 1 getconf` and getconf(1p) `man 1p getconf`.
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
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