[Python-ideas] shutil.symlink to allow non-race replacement of existing link targets

[Antoine Pitrou]

On Thu, 16 May 2019 18:05:39 +0300
Serhiy Storchaka <storchaka at gmail.com>
wrote:
> 16.05.19 17:05, Antoine Pitrou пише:
> > On Thu, 16 May 2019 16:04:36 +0300
> > Serhiy Storchaka <storchaka at gmail.com>
> > wrote:  
> >> 16.05.19 14:33, Antoine Pitrou пише:  
> >>> On Thu, 16 May 2019 13:05:48 +0300
> >>> Serhiy Storchaka <storchaka at gmail.com>
> >>> wrote:  
> >>>> 16.05.19 11:28, Barry Scott пише:  
> >>>>> To replace one symlink with another atomically is possible by using rename() or renameat()
> >>>>> something like:
> >>>>>
> >>>>> 	os.symlink( src, tmp_symlink )
> >>>>> 	os.rename( tmp_symlink, dst )  
> >>>>
> >>>> Somebody can replace tmp_symlink between os.symlink() and os.rename().  
> >>>
> >>> Not if tmp_symlink is created in a directory with strict permissions, I
> >>> guess.  
> >>
> >> But in such case we do not need complex games with a temporary symlink.
> >> Just use os.symlink() and os.unlink() if needed.  
> > 
> > I was talking about the *tmp_symlink*, not *dst*.  
> 
> They both should be on the same file system. The simplest way to achieve 
> this is to create tmp_symlink in the same directory as dst.

So what?