cygwin_conv_path strange behavior

cygwin_conv_path strange behavior

[Jan Nijtmans]

Dear cygwin developers.

When trying the function cygwin_conv_path, I noted
some strange effect, when the cygwin1.dll is in the
same directory as the executable. This can be
demonstrated with the example "mypath.c" below.

Compiling this function, and putting it in some
directory "C:\some\path\foo', from a cygwin shell,
it prints:
    $ ./mypath
    win32 path: C:\some\path\foo\mypath.exe
    posix path: /cygdrive/c/some/path/foo/mypath.exe
From a win32 command shell:
    > .\mypath
    win32 path: C:\some\path\foo\mypath.exe
    posix path: /cygdrive/c/some/path/foo/mypath.exe
This is as expected.


Now, copy cygwin1.dll to the same directory
as mypath.exe, and do the same
from a cygwin shell, it prints:
    $ ./mypath
    win32 path: C:\some\path\foo\mypath.exe
    posix path: /cygdrive/c/some/path/foo/mypath.exe
From a win32 command shell:
    > .\mypath
    win32 path: C:\some\path\foo\mypath.exe
    posix path: /foo/mypath.exe

In other words, the first part of the posix path is
stripped, when running it from a win32 shell!

My objective is to distribute "mypath.exe" separate
from cygwin, simply by putting cygwin1.dll (the only
one it needs) in the same directory as the executable,
so it can run without the presence of the cygwin
environment. But this results in wrong paths produced
by the cygwin_conv_path() function.

Is this a bug in cygwin_conv_path()? What can
I do about that?

Regards,
           Jan Nijtmans

=============== mypath.c =================
extern __stdcall int GetModuleFileNameA(void *, const char *, int);

#define PATH_MAX 512

int
main ()
{
	char buf[PATH_MAX];
	char name[PATH_MAX];

	GetModuleFileNameA(0, buf, PATH_MAX);
	cygwin_conv_path(2, buf, name, PATH_MAX);
	printf("win32 path: %s\nposix path: %s\n", buf, name);
}

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

Re: cygwin_conv_path strange behavior

[Earnie Boyd]

On Wed, Jun 27, 2012 at 7:59 AM, Jan Nijtmans wrote:
>
> Now, copy cygwin1.dll to the same directory
> as mypath.exe, and do the same
> from a cygwin shell, it prints:
>    $ ./mypath
>    win32 path: C:\some\path\foo\mypath.exe
>    posix path: /cygdrive/c/some/path/foo/mypath.exe
> From a win32 command shell:
>    > .\mypath
>    win32 path: C:\some\path\foo\mypath.exe
>    posix path: /foo/mypath.exe
>

This sounds it is as expected.  You copied only cygwin1.dll so the
shell you started had a cygwin1.dll in another directory so that / is
mapped to the parent directory containing the cygwin1.dll the shell is
using.  However, when you use the win32 command shell there is no
previous mapping of / to the parent directory containing cygwin1.dll
so / is mapped to c:/some/path and the function correctly reports
/foo/mypath.exe.

-- 
Earnie
-- https://sites.google.com/site/earnieboyd

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

Re: cygwin_conv_path strange behavior

[Jan Nijtmans]

2012/6/27 Earnie Boyd <earnie@users.sourceforge.net>:
> On Wed, Jun 27, 2012 at 7:59 AM, Jan Nijtmans wrote:
>>
>> Now, copy cygwin1.dll to the same directory
>> as mypath.exe, and do the same
>> from a cygwin shell, it prints:
>>    $ ./mypath
>>    win32 path: C:\some\path\foo\mypath.exe
>>    posix path: /cygdrive/c/some/path/foo/mypath.exe
>> From a win32 command shell:
>>    > .\mypath
>>    win32 path: C:\some\path\foo\mypath.exe
>>    posix path: /foo/mypath.exe
>>
>
> This sounds it is as expected.  You copied only cygwin1.dll so the
> shell you started had a cygwin1.dll in another directory so that / is
> mapped to the parent directory containing the cygwin1.dll the shell is
> using.  However, when you use the win32 command shell there is no
> previous mapping of / to the parent directory containing cygwin1.dll
> so / is mapped to c:/some/path and the function correctly reports
> /foo/mypath.exe.

OK, so cygwin1.dll always maps "/" to its parent directory, if no other
mapping can be found. But from a win32 command shell, I don't
need such a mapping, I just want to know the full path
where the executable is. How can I influence that?

Thanks!

Regards,
            Jan Nijtmans

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

Re: cygwin_conv_path strange behavior

[Corinna Vinschen]

On Jun 27 13:59, Jan Nijtmans wrote:
> My objective is to distribute "mypath.exe" separate
> from cygwin, simply by putting cygwin1.dll (the only
> one it needs) in the same directory as the executable,

"Distribute?"

http://cygwin.com/licensing.html


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple