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to follow or not to follow a symlink in os.utime() os POSIX - Printable Version

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to follow or not to follow a symlink in os.utime() os POSIX - Skaperen - Sep-03-2023

in "16.1. os — Miscellaneous operating system interfaces" there is this text (in my PDF copy of "The Python Library Reference"):
Output:
You can check whether or not follow_symlinks is supported on your platform using os.supports_follow_symlinks.  If it is unavailable, using it will raise a NotImplementedError
what is meant by "using"? trying to access it as an attribute? checking if the attribute exists? what is the appropriate way to test if the platform a script is running on supports this?

my experience from my days of coding most everything in C told me that every platform supported following a symlink and some did NOT support NOT following a symlink. so, it seems this test should be the other way around. there should be os.supports_nofollow_symlinks which would be like AT_SYMLINK_NOFOLLOW in C (defined in fcntl.h so utimnsat(2) can use it).

RE: to follow or not to follow a symlink in os.utime() os POSIX - Gribouillis - Sep-03-2023

(Sep-03-2023, 05:34 PM)Skaperen Wrote: what is meant by "using"? trying to access it as an attribute?
They mean that some functions in the os module have a follow_symlinks= keyword argument in their parameter list, for example the 
os.stat()
function has such a parameter.

On my system, I have
>>> import os
>>> os.stat in os.supports_follow_symlinks
True
It means that I can use the follow_symlinks argument and call e.g.
os.stat(..., follow_symlinks=False)
On other systems, one cannot set this argument to False.

RE: to follow or not to follow a symlink in os.utime() os POSIX - Skaperen - Sep-04-2023

so, you are saying "You can check whether or not follow_symlinks is supported on your platform" refers to support of the keyword argument by the Python implementation/configuration on your platform/host, not support of that being doable by the platform?

RE: to follow or not to follow a symlink in os.utime() os POSIX - Skaperen - Sep-04-2023

(Sep-03-2023, 06:28 PM)Gribouillis Wrote: os.stat in os.supports_follow_symlinks
and it gives a set of functions that the support applies to (as opposed to all functions documented with that argument)?

RE: to follow or not to follow a symlink in os.utime() os POSIX - Gribouillis - Sep-04-2023

(Sep-04-2023, 01:31 AM)Skaperen Wrote: and it gives a set of functions that the support applies to
Exactly
>>> import os
>>> os.supports_follow_symlinks
{<built-in function link>, <built-in function chown>, <built-in function utime>, <built-in function stat>, <built-in function access>}
>>>