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Re: syntax for Cygwin bash invoking Win apps


On Wed, Sep 09, 2009 at 12:10:44PM -0400, Mark J. Reed wrote:
>On Wed, Sep 9, 2009 at 12:05 PM, Christopher Faylor wrote:
>>>>>> $ cmd /c echo "\"abc\""
>>>>>> "\"abc\""
>>>>>>
>>>>>> # Wahhh?!
>>>>>>
>>>>>> Anyone who knows the explanation would make me very grateful. I've tried
>>>>>> this with other Windows apps too, and the same weirdness seems to occur.
>>>
>>>Larry Hall:
>>>>>All of the above is consistent with bash shell quoting.
>>>
>>>No, it's really not. ??Those backslashes should be long gone by the
>>>time cmd.exe gets its arguments, yet it echoes them. ??It seems that
>>>the Cygwin version of bash stops short before doing some of the work
>>>it normally does itself on other systems, assuming the executed
>>>command will have its command line run through the preprocessor in the
>>>Cygwin DLL.
>>
>> Actually, I'd say that was cmd doing something funky. ??It's hard to believe
>> that bash was actually special-casing cmd.exe.
>
>I don't think it's special-casing cmd.exe.  I think some of the
>command line processing that is done by bash on Linux has been moved
>out of bash and into the DLL command line preprocessor on Cygwin.

Cygwin does quote individual arguments if they contain "special"
characters like quotes or spaces when sending a command-line to a
windows program.  It's up to the windows program to understand quoting.

I tried renaming cmd.exe to foo.exe and there is no difference in
behavior but a mingw program which just echoes arguments does the right
thing.  So, the bottom line is that you can't rely on quoting behavior
with cmd's built-in echo.

cgf

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