Re: cp -p loses precision on the timestamp of the copy

[Eric Blake]

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According to Ray Liere on 1/31/2008 7:53 PM:
| Consider the following use of cp -p to create an identical copy (identical
| in content and in timestamps, etc.):
|
| # echo xxx > jnk
| # ls --full-time jnk
| -rw-------  1 root root 4 2008-01-31 18:40:27.879358240 -0800 jnk
| # cp -p jnk jnkcopy
| # ls --full-time jnk*
| -rw-------  1 root root 4 2008-01-31 18:40:27.879358240 -0800 jnk
| -rw-------  1 root root 4 2008-01-31 18:40:27.879358000 -0800 jnkcopy

Thanks for the report.  However...

| # ls --version
| ls (coreutils) 5.2.1

That release is VERY old, and many bug-fixes have been made in the
meantime.  The latest stable version is 6.10.  Furthermore, coreutils
suffers from the fact that until very recently, there has been no
standardized way of setting nanosecond file resolutions.  The next version
of POSIX is adding futimensat, but most OS's have not implemented it yet.
~ Therefore, if the OS provides no method for finer granularity, coreutils
has no choice but to truncate the timestamp, so this is likely not a bug
in cp.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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