C / C++ / MFC

8-Dec-08 22:40

I got this old Fortran exe and I have to embed in in C++. After starting it needs two filenames entered by the user. I did this by putting the filenames in files, attaching handles to them, making a Pipe and attaching it to the child process, then doing ReadFile and WriteFile to the pipe, as shown in MSDN.

Anyway, it gets the strings holding the filenames. I have to append \n else Fortran won't accept it. The Fortran people advised me to try with \r before \n, it seems to grab that too. C++ can append a \0 if I let it, I tried that too.

However, when it takes the first string and tries to open the file, it can't do it and it returns an error. (It returns the error tidily to my C++ process, so it can't be that bad.)
If I run it directly from the command line, as the original author did, it all works fine with the same files. So there must be something wrong with the way I pass my strings.

Unfortunately I can see into the Fortran code but I can't get at it to see what the problem is. We have some old Fortran compilers lying about, but they won't even compile it. The original came from Linux, can that have something to do with it? The users have real problems if they use a Windows editor, it doesn't like Windows carriage returns, they say. But I run it from the command line and it reads all kinds of other files I generated with C++.

There must be someone out there who has done this before?

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Bibo ergo sum

Defenestration8-Dec-08 22:44

Defenestration

8-Dec-08 22:44

If it runs OK from the command-line, why don't you pass in the filenames on the command-line when you call CreateProcess() ?

RedSonja8-Dec-08 22:51

8-Dec-08 22:51

It runs fine if I type in first "fortran.exe 1>test.out 2>test.log", then the two filenames "input.dat" and "test", both followed by CR. The Fortran.exe is waiting for two inputs on UNIT=5. My problem was to embed all this in my real-time stuff, so it gets called without the user realising. As far as I know that bit works, it does continue after it is fooled into believing it has 2 keyboard inputs. It just doesn't like the inputs.

Did I go to all that trouble when there was an easier way of doing it? I couldn't even get a batch file to do it.

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Bibo ergo sum

Defenestration8-Dec-08 22:59

Defenestration

8-Dec-08 22:59

Oh, I didn't realise the fortran.exe program gets the input for the two filenames.

Luc Pattyn9-Dec-08 0:00

9-Dec-08 0:00

Hi,

have you tried passing the Fortran exe filenames ending on \r (i.e. without any \n)?

can you determine whether it is the first or the second file it fails to open? I suspect it
understands only one line terminator, and the other one (if you use \r AND \n) is left unrecognized
in the other filename.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

RedSonja9-Dec-08 0:09

9-Dec-08 0:09

So many answers, such kind people... This is what I came for.

Anyway, yes, I tried just \r but these were not recognised as strings i.e. IOSTAT was not 0.

READ(5,'(A)',IOSTAT=IOS) FILEN
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A FILE NAME'
READ(5,'(A)',IOSTAT=IOS) FLBASE
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A ROOT FILE NAME' *** it complained here

Now, with \n or with \r\n it takes the strings and continues. It is the first file it fails to open. I wonder why it complains at the second input and not at the first.
Maybe I should input both in the same string... You may have something there with the line terminators... Shall try that.

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Bibo ergo sum

Garth J Lancaster9-Dec-08 0:22

Garth J Lancaster

9-Dec-08 0:22

if you have 'a' fortran compiler that does work, why dont you create a stub / test exe yourself, accepting two filenames for example - experiment with that in place of the precompiled exe you've got - you can put some debug writes etc in your copy to see what works etc ...

oh.. you dont say what the value of IOS is ... this is intel fortran, but checking for one of these may reveal more info ..

http://www.intel.com/software/products/compilers/docs/flin/main_for/mergedProjects/bldaps_for/common/bldaps_rterrs.htm[^]

'g'

RedSonja9-Dec-08 2:18

9-Dec-08 2:18

I tried to look at the error code but it is a little smiley in my command window. I have to find out how to format Fortran to write in hex, oh dear.

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Bibo ergo sum

Luc Pattyn9-Dec-08 0:23

9-Dec-08 0:23

Hi,

I would try "filename1\rfilename2\r" as a single string; I suspect \r is the right separator
for Fortran, NULL is needed on the sender side, and an extra NULL in between the filenames
ends up in FLBASE[1].

If the final NULL is confusing something else later on, there are ways to send a string without
a terminating NULL too.

A final thought:

I understand you can no longer compile the full Fortran app.

If your tests fail to show the way, you could write just a small Fortran program that tests
the communication and shows all the characters that actually get read into FILEN and FLBASE.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

RedSonja9-Dec-08 1:26

Re: Passing filename from C++ to Fortran [modified]

9-Dec-08 1:26

No, putting them in one string didn't work, it really wants two, with \n. It doesn't seem to care about C++'s \0. Does it read them out of the pipe in the same order as I put them in? I tried both ways but it didn't work either.

That is a good idea with the little test program. I have just written my first Fortran code in 20 years. Ugh, they call that a debugger? I shall now try and run that from C++. Progress report to follow...

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Bibo ergo sum

RedSonja9-Dec-08 2:03

9-Dec-08 2:03

What happened? When I call my little ftest.exe from the debugger or from the command window it works, I have to enter the two strings by hand. I can see that it has filled the input strings up to 80 chars, but still manages to open the file.

When I call it from C++ it fills the strings up to 80 chars, but can't open the file. I tried terminating with \n, with \r\n, and with \r\n\0, it all made no difference.

There must be something else. This is very strange.

READ(5,'(A)',IOSTAT=IOS) FILEN

It must be the '(A)'

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Bibo ergo sum

modified on Tuesday, December 9, 2008 8:22 AM

Luc Pattyn9-Dec-08 2:29

Re: Passing filename from C++ to Fortran [modified]

9-Dec-08 2:29

Hi,

AFAIK '(A)' just means "take any text"

I suggest you:
- make sure your debugging stuff visualizes all special chars including space, NULL, CR, LF
- display the status of both openfile operations, I mean the actual value so you can google it
(a >0 test is not sufficient)
- try the Fortran test app manually with different paths
- show us all the relevant Fortran code

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

RedSonja9-Dec-08 2:33

9-Dec-08 2:33

This is the entire code:
PROGRAM FTEST
IMPLICIT NONE
C
INTEGER IOS
CHARACTER*80 FILEN, FLBASE

C
C
CONTINUE
READ(5,'(A)',IOSTAT=IOS) FILEN
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A FILE NAME'
WRITE (6) 'FILEN = *', FILEN, '*'
READ(5,'(A)',IOSTAT=IOS) FLBASE
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A ROOT FILE NAME'
WRITE (6) 'FLBASE = *', FLBASE, '*'

OPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD',
$ READONLY,IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
WRITE (6, FMT=*) 'ERROR NO INPUT FILE ', IOS
ELSE
WRITE (6) 'OPENED INPUT FILE OK'
ENDIF
C
CONTINUE
END

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Bibo ergo sum

modified on Tuesday, December 9, 2008 8:46 AM

Luc Pattyn9-Dec-08 2:40

9-Dec-08 2:40

OK, now

1. what is the result opening the first file? is it ERROR ... or OK on first file?
2. where is the opening of the second file? and what is its result?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. Confused | :confused:

RedSonja9-Dec-08 2:43