Using INQUIRE to test if a directory exists

INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
for the existence of a directory with all my Windows compilers
(g95,gfortran,lf95) except IVF. Does anybody know the reason for this
and what the standard says if anything?

Al Greynolds
www.ruda.com

Al Greynolds wrote:

> INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
> for the existence of a directory with all my Windows compilers
> (g95,gfortran,lf95) except IVF. Does anybody know the reason for this
> and what the standard says if anything?

it would be ambiguous? On some systems, there isn't even a concept of a
directory. There may be a "qualifier/account number" associated, but
nothing like a directory, so the standard shouldn't really say that a
"file" and a "directory" should be detected portably across OS'. There
are situations when you actually want to differentiate between a file
and a directory, and you can't using this syntax without prior
knowledge. Didn't IVF add some extensions specifically for querying
directories? CVF does handle directories with the above inquire statement.

>
> Al Greynolds
> www.ruda.com
>
>


--

Gary Scott
mailto:garylscott@sbcglobal dot net

Fortran Library: http://www.fortranlib.com

Support the Original G95 Project: http://www.g95.org
-OR-
Support the GNU GFortran Project: http://gcc.gnu.org/fortran/index.html

If you want to do the impossible, don't hire an expert because he knows
it can't be done.

-- Henry Ford

On Aug 21, 2:31*pm, Gary Scott <garylsc...@sbcglobal.net> wrote:
> Didn't IVF add some extensions specifically for querying
> directories?

Yes they did, but I was looking for something that is portable (at
least among the compilers I use). Its interesting that they changed
the default behavior from CVF to IVF.

Anyway its not a big deal just a curiosity.

Al

Al Greynolds <awgreynolds@earthlink.net> wrote:

> INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
> for the existence of a directory with all my Windows compilers
> (g95,gfortran,lf95) except IVF. Does anybody know the reason for this
> and what the standard says if anything?

The Fortran standard does not even have the concept of a directory (and
Fortran has been implemented on systems that don't have such a thing),
so it says nothing about it.

As I recall, the C standard is actually quite simillar in not having
such a concept. Sure there are widely used C libraries that do, but I
don't recall that it was directly in the C standard.

--
Richard Maine | Good judgement comes from experience;
email: last name at domain . net | experience comes from bad judgement.
domain: summertriangle | -- Mark Twain

Al Greynolds wrote:

> On Aug 21, 2:31 pm, Gary Scott <garylsc...@sbcglobal.net> wrote:
>
>>Didn't IVF add some extensions specifically for querying
>>directories?
>
>
> Yes they did, but I was looking for something that is portable (at
> least among the compilers I use). Its interesting that they changed
> the default behavior from CVF to IVF.

I'm pretty sure I was one that complained about the way DVF or CVF
implemented this. I had a specific situation where I needed to
differentiate a directory from a file (file names don't have to have
extensions/types suffixed to them). So I may or may not have had some
tiny influence on it being changed (don't know, assume it would take
lots of complaints or some other serious reason to change it).

>
> Anyway its not a big deal just a curiosity.
>
> Al


--

Gary Scott
mailto:garylscott@sbcglobal dot net

Fortran Library: http://www.fortranlib.com

Support the Original G95 Project: http://www.g95.org
-OR-
Support the GNU GFortran Project: http://gcc.gnu.org/fortran/index.html

If you want to do the impossible, don't hire an expert because he knows
it can't be done.

-- Henry Ford

I heard that one trick is to quote the directory name followed by
".nul' as the filename to test for.
This was supposed to return a .TRUE. response if the directory
existed.
But this may be platform dependent.

Note: this is a memory, which may be wrong.
I personally use non-portable methods myself..

On 21 aug, 23:18, Al Greynolds <awgreyno...@earthlink.net> wrote:
> INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
> for the existence of a directory with all my Windows compilers
> (g95,gfortran,lf95) except IVF. *Does anybody know the reason for this
> and what the standard says if anything?
>
> Al Greynoldswww.ruda.com

On Windows and Linux/UNIX/OSX a directory contains a special
file named ".". You might try:

INQUIRE( FILE = 'mydirectory/.', EXIST = exists )

Regards,

Arjen

On 22 août, 08:51, Arjen Markus <arjen.mar...@wldelft.nl> wrote:
> On 21 aug, 23:18, Al Greynolds <awgreyno...@earthlink.net> wrote:
>
> > INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
> > for the existence of a directory with all my Windows compilers
> > (g95,gfortran,lf95) except IVF. Does anybody know the reason for this
> > and what the standard says if anything?
>
> > Al Greynoldswww.ruda.com
>
> On Windows and Linux/UNIX/OSX a directory contains a special
> file named ".". You might try:
>
> INQUIRE( FILE = 'mydirectory/.', EXIST = exists )
>
> Regards,
>
> Arjen

To be a little bit more portable, I also use an environment variable
called for instance DELIMITER which is equals to "\" on Windows and
"/" on unix :

CHARACTER :: delimiter
...
CALL get_environment_variable('DELIMITER',delimiter)
INQUIRE(file='mydirectory'//delimiter//'.',EXIST=exist)

On 22 aug, 13:38, fj <francois.j...@irsn.fr> wrote:
> On 22 août, 08:51, Arjen Markus <arjen.mar...@wldelft.nl> wrote:
>
>
>
>
>
> > On 21 aug, 23:18, Al Greynolds <awgreyno...@earthlink.net> wrote:
>
> > > INQUIRE(FILE='some directory specification',EXIST=ex) correctly tests
> > > for the existence of a directory with all my Windows compilers
> > > (g95,gfortran,lf95) except IVF. *Does anybody know the reason for this
> > > and what the standard says if anything?
>
> > > Al Greynoldswww.ruda.com
>
> > On Windows and Linux/UNIX/OSX a directory contains a special
> > file named ".". You might try:
>
> > INQUIRE( FILE = 'mydirectory/.', EXIST = exists )
>
> > Regards,
>
> > Arjen
>
> To be a little bit more portable, I also use an environment variable
> called for instance DELIMITER which is equals to "\" on Windows and
> "/" on unix :
>
> CHARACTER :: delimiter
> ...
> CALL get_environment_variable('DELIMITER',delimiter)
> INQUIRE(file='mydirectory'//delimiter//'.',EXIST=exist)- Tekst uit oorspronkelijk bericht niet weergeven -
>
> - Tekst uit oorspronkelijk bericht weergeven -

Of course , though I recently tried to see if a forward slash
would be acceptable on Windows (I used three different compilers)
and they all accepted both a / and a \ as a directory delimiter.

Regards,

Arjen

On 22 août, 14:07, Arjen Markus <arjen.mar...@wldelft.nl> wrote:
> On 22 aug, 13:38, fj <francois.j...@irsn.fr> wrote:
>
>
>
> > On 22 août, 08:51, Arjen Markus <arjen.mar...@wldelft.nl> wrote:
>
> > > On 21 aug, 23:18, Al Greynolds <awgreyno...@earthlink.net> wrote:
>
> > > > INQUIRE(FILE='some directory specification',EXIST=ex) correctlytests
> > > > for the existence of a directory with all my Windows compilers
> > > > (g95,gfortran,lf95) except IVF. Does anybody know the reason for this
> > > > and what the standard says if anything?
>
> > > > Al Greynoldswww.ruda.com
>
> > > On Windows and Linux/UNIX/OSX a directory contains a special
> > > file named ".". You might try:
>
> > > INQUIRE( FILE = 'mydirectory/.', EXIST = exists )
>
> > > Regards,
>
> > > Arjen
>
> > To be a little bit more portable, I also use an environment variable
> > called for instance DELIMITER which is equals to "\" on Windows and
> > "/" on unix :
>
> > CHARACTER :: delimiter
> > ...
> > CALL get_environment_variable('DELIMITER',delimiter)
> > INQUIRE(file='mydirectory'//delimiter//'.',EXIST=exist)- Tekst uit oorspronkelijk bericht niet weergeven -
>
> > - Tekst uit oorspronkelijk bericht weergeven -
>
> Of course , though I recently tried to see if a forward slash
> would be acceptable on Windows (I used three different compilers)
> and they all accepted both a / and a \ as a directory delimiter.
>
> Regards,
>
> Arjen

Even a microsoft compiler ?