Is this a bug or a behavior?

Centrych Administrator admin@centrych.org
Fri Feb 15 05:29:00 GMT 2013


On 02/13/2013 11:55 AM, Adam Dinwoodie wrote:
> Yes. If you ask for a file, the file doesn't exist, but the file with 
> a .exe extension exists, Cygwin will refer you to the .exe version of 
> the file. See 
> <http://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-exe>. 

Thanks, already aware of that, and it's why I raised this question.

> From that point of view it is; Cygwin is self-consistent, but the very 
> nature of attempting to write a Linux-like interface on a 
> fundamentally non-Linux like OS means such issues can't be avoided.

I'm not clear on what your standard for "self-consistent" is, or why 
filenames are an interface issue.

Those aside, consider these two lines:

     $ rm -rf * && mkdir a && touch grep && cp grep /bin/grep a
     $ rm -rf * && mkdir a && touch grep && cp /bin/grep grep a

The first line executes as expected while the second, which reverses the 
order of files, fails after copying the .exe with the following:

     cp: cannot create regular file `a/grep': File exists

Now, take these two sets:

     $ rm -rf * && touch foo grep && cp /bin/grep.exe .
     $ mv foo grep && ls -i

     $ rm -rf * && touch foo && cp /bin/grep.exe .
     $ mv -n foo grep

The first set works as expected while the second deletes grep.exe during 
the rename even though no-clobber is explicitly passed to mv.

> Nobody has yet suggested a more consistent alternative that still 
> allows, for example, a Linux shell script that calls unadorned "grep" 
> to work on Cygwin.

How can it ever be consistent while 'filename' and filename.exe' are 
allowed to exist in the same directory?

Is there some way to differentiate between a Windows .exe and a Cygwin 
binary, like grep.exe, that's intended to execute within the Cygwin 
environment?

> For your (I really hope) contrived example... 

Unfortunately, it wasn't contrived.  It was an actual question in a BASH 
scripting module that I unnecessarily have to slog through.



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