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+--- Thread: looks like i need to learn ... (/thread-30492.html)
looks like i need to learn ... - Skaperen - Oct-23-2020
looks like i need to learn interfacing Python to C. just too many syscalls that are not implemented.
RE: looks like i need to learn ... - Gribouillis - Oct-23-2020
This is a rather cryptic statement. What are you trying to do?
RE: looks like i need to learn ... - Skaperen - Oct-23-2020
... a number of different syscalls that i could not find an implementation or stub for, such as pivot_root() and utimensat().
RE: looks like i need to learn ... - Gribouillis - Oct-23-2020
If I understand well,
os.utime() has a ns argument that achieves the functionality of utimensat.Also the butter project in Pypi claims it has
pivot_root(). I have not tried it...
RE: looks like i need to learn ... - Skaperen - Oct-23-2020
i searched the Python library manual for "utimens" and found nothing that way. what should i have searched for?
RE: looks like i need to learn ... - Gribouillis - Oct-23-2020
Skaperen Wrote:what should i have searched for?At some point, there was utimensat in the Python library.
RE: looks like i need to learn ... - Skaperen - Oct-24-2020
was it removed or renamed?
they could implement support for the -at functions by allowing a 2-tuple of (int,str/bytes) in place of str/bytes for the file path. then no new names would be needed. i wonder if they did that with this as a 3rd option.
RE: looks like i need to learn ... - Skaperen - Oct-24-2020
to represent nanoseconds in float would require 61 bits of precision. but float is C double which is only 53 bits on x86/amd platforms. they just barely achieve microsecond precision (51 bits needed). so something more is needed:
- C long double (64 bits)
- decimal.Decimal
- (sec,nsec)
- more function names
just because a bunch of low numbers can be unique in float does not mean higher ones can. in platforms with 32 bits, int values for seconds can be as high as 2**31-1 (signed). that uses 31 bits of the available precision in float, leaving 22 bits for a fractional part. today is just 1 bit short of that.
i can dream of a world where the standard float size has at least 64 bits of precision. but i must wake up to review python-forum.