R devel - Oct 2023 - system()/system2() using short paths of commands on Windows?

Hi,

It may have been so for 20+ years but I just discovered today that system()
would always try to use the short path of a command on Windows:
https://github.com/wch/r-source/blob/635a67/src/gnuwin32/run.c#L141 If
that's true, I wonder if it could provide an option to disable this
behavior, because we recently ran into a case in which short paths wouldn't
work. I wonder what the original motivation of using short paths was. If it
was to avoid spaces in paths, wouldn't shQuote() work? Thanks!

Regards,
Yihui

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On 10/30/23 17:18, Yihui Xie wrote:
> Hi,
>
> It may have been so for 20+ years but I just discovered today that system()
> would always try to use the short path of a command on Windows:
> https://github.com/wch/r-source/blob/635a67/src/gnuwin32/run.c#L141 If
> that's true, I wonder if it could provide an option to disable this
> behavior, because we recently ran into a case in which short paths
wouldn't
> work. I wonder what the original motivation of using short paths was. If it
> was to avoid spaces in paths, wouldn't shQuote() work? Thanks!
Could you please file a minimal reproducible example that exhibits the 
problem caused by an attempt to translate to short path names (note 
there is a fallback to long path names)? In principle, short path names 
should work when they are returned by Windows, this should not be 
causing any trouble.

Thanks
Tomas
>
> Regards,
> Yihui
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

On 30/10/2023 16:18, Yihui Xie wrote:
> Hi,
> 
> It may have been so for 20+ years but I just discovered today that system()
> would always try to use the short path of a command on Windows:
> https://github.com/wch/r-source/blob/635a67/src/gnuwin32/run.c#L141 If
> that's true, I wonder if it could provide an option to disable this
> behavior, because we recently ran into a case in which short paths
wouldn't
> work. I wonder what the original motivation of using short paths was. If it
> was to avoid spaces in paths, wouldn't shQuote() work? Thanks!
No: system on Windows does not use a shell.

The 'original motivation' was to work reliably!  Back in the days of 
Windows 95 when many parts of Windows only supported 8+3 names.
> 
> Regards,
> Yihui
> 
> 	[[alternative HTML version deleted]]
Please do re-read the posting guide.  It has ' been so for 20+ years '.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford