Passing filename from C++ to Fortran
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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)'
------------- Bibo ergo sum
modified on Tuesday, December 9, 2008 8:22 AM
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 :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
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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 :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
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
------------- Bibo ergo sum
modified on Tuesday, December 9, 2008 8:46 AM
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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
------------- Bibo ergo sum
modified on Tuesday, December 9, 2008 8:46 AM
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? :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
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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? :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
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It gives me an IOS=2 on the first file. I will worry about the second string another day, it gets used to build some complicated output filenames.
------------- Bibo ergo sum
Hi, Not sure but maybe IOS=2 means "the file you want to read exists but is empty". Please check. I expect IOS=6 for "no such file", IOS=0 for anything else (until you start working on the file that is) unless the filename is invalid (not sure which code gets emited then). You could try creating and writing the file, rather than opening and reading; that way, Explorer (or DOS DIR) would show the effective filename. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
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It gives me an IOS=2 on the first file. I will worry about the second string another day, it gets used to build some complicated output filenames.
------------- Bibo ergo sum
Hi, I installed Silverfrost F95 and was able to run this:
PROGRAM FTEST
IMPLICIT INTEGER(I-N)INTEGER IOS
CHARACTER*80 FILEN, FLBASE
CHARACTER CPRINT *,'enter filename1'
READ(5,'(A)',IOSTAT=IOS) FILEN
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A FILE NAME'
PRINT *, 'FILEN = *', FILEN, '*'
DO 10 I = 1,80
C=FILEN(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FILEN[',I,']=',C,'=',ICHAR(C)
10 CONTINUEPRINT *,'enter filename2'
READ(5,'(A)',IOSTAT=IOS) FLBASE
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A ROOT FILE NAME'
PRINT *, 'FLBASE = *', FLBASE, '*'
DO 20 I = 1,80
C=FLBASE(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FLBASE[',I,']=',C,'=',ICHAR(C)
20 CONTINUEOPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 1 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 1 OK'
ENDIF
OPEN(18,FILE=FLBASE,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 2 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 2 OK'
ENDIFEND
it gives OK for existing files, and error 128 for non-existing files. The documentation says error codes could be different on different compilers. So it is my guess something is wrong in the way you pass the filenames from C++; anyway the above should be able to tell you what gets read. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
-
Hi, I installed Silverfrost F95 and was able to run this:
PROGRAM FTEST
IMPLICIT INTEGER(I-N)INTEGER IOS
CHARACTER*80 FILEN, FLBASE
CHARACTER CPRINT *,'enter filename1'
READ(5,'(A)',IOSTAT=IOS) FILEN
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A FILE NAME'
PRINT *, 'FILEN = *', FILEN, '*'
DO 10 I = 1,80
C=FILEN(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FILEN[',I,']=',C,'=',ICHAR(C)
10 CONTINUEPRINT *,'enter filename2'
READ(5,'(A)',IOSTAT=IOS) FLBASE
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A ROOT FILE NAME'
PRINT *, 'FLBASE = *', FLBASE, '*'
DO 20 I = 1,80
C=FLBASE(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FLBASE[',I,']=',C,'=',ICHAR(C)
20 CONTINUEOPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 1 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 1 OK'
ENDIF
OPEN(18,FILE=FLBASE,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 2 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 2 OK'
ENDIFEND
it gives OK for existing files, and error 128 for non-existing files. The documentation says error codes could be different on different compilers. So it is my guess something is wrong in the way you pass the filenames from C++; anyway the above should be able to tell you what gets read. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
Luc Pattyn wrote:
I installed Silverfrost F95
nice one Luc - thats dedication !!! 'g'
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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?
------------- Bibo ergo sum
Another possible difference to running it from the command line is the location of the working directory (I note that you seem to be using filenames and not full paths). Maybe you are now successfully transferring the filenames but the working directory is different, perhaps somewhere where the program doesn't have permission, or a file that should exist in it doesn't. The statement: OPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD', $ READONLY,IOSTAT=IOS) will give you some sort of error if the file doesn't exist as STATUS='OLD' tells the program that it should be there.
Peter "Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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Another possible difference to running it from the command line is the location of the working directory (I note that you seem to be using filenames and not full paths). Maybe you are now successfully transferring the filenames but the working directory is different, perhaps somewhere where the program doesn't have permission, or a file that should exist in it doesn't. The statement: OPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD', $ READONLY,IOSTAT=IOS) will give you some sort of error if the file doesn't exist as STATUS='OLD' tells the program that it should be there.
Peter "Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
Yes yes yes! I put the whole path in (without doubling the \) and the test program works. It doesn't work for the original Fortran yet but at least I know where to start. If Fortran is only going to give it 80 chars every time I can see some problems coming up on the target machine, because the paths can get a lot longer. I did try a relative path but it wasn't having it, must try and get Fortran to tell me where it is. In C++ I use _getcwd, can someone tell me how to get it in Fortran? It was giving me IOS=2, which is not in the list of Intel error messages.
------------- Bibo ergo sum
-
Hi, I installed Silverfrost F95 and was able to run this:
PROGRAM FTEST
IMPLICIT INTEGER(I-N)INTEGER IOS
CHARACTER*80 FILEN, FLBASE
CHARACTER CPRINT *,'enter filename1'
READ(5,'(A)',IOSTAT=IOS) FILEN
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A FILE NAME'
PRINT *, 'FILEN = *', FILEN, '*'
DO 10 I = 1,80
C=FILEN(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FILEN[',I,']=',C,'=',ICHAR(C)
10 CONTINUEPRINT *,'enter filename2'
READ(5,'(A)',IOSTAT=IOS) FLBASE
IF ( IOS .NE. 0 ) STOP 'MUST PROVIDE A ROOT FILE NAME'
PRINT *, 'FLBASE = *', FLBASE, '*'
DO 20 I = 1,80
C=FLBASE(I:I)
IF (ICHAR(C).NE.32) PRINT *, 'FLBASE[',I,']=',C,'=',ICHAR(C)
20 CONTINUEOPEN(17,FILE=FILEN,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 1 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 1 OK'
ENDIF
OPEN(18,FILE=FLBASE,FORM='FORMATTED',STATUS='OLD',IOSTAT=IOS)
IF ( IOS .NE. 0 ) THEN
PRINT *, 'ERROR NO INPUT FILE 2 ', IOS
ELSE
PRINT *, 'OPENED INPUT FILE 2 OK'
ENDIFEND
it gives OK for existing files, and error 128 for non-existing files. The documentation says error codes could be different on different compilers. So it is my guess something is wrong in the way you pass the filenames from C++; anyway the above should be able to tell you what gets read. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
-
Yes yes yes! I put the whole path in (without doubling the \) and the test program works. It doesn't work for the original Fortran yet but at least I know where to start. If Fortran is only going to give it 80 chars every time I can see some problems coming up on the target machine, because the paths can get a lot longer. I did try a relative path but it wasn't having it, must try and get Fortran to tell me where it is. In C++ I use _getcwd, can someone tell me how to get it in Fortran? It was giving me IOS=2, which is not in the list of Intel error messages.
------------- Bibo ergo sum
To find out where you are, GNU Fortran has a GETCWD call link[^] I don't know how standard it is. It doesn't seem to have a corresponding SETCWD call. If you are starting the program using CreateProcess() then you can set the working directory, and I think it will default to the working directory of the calling process if you don't.
Peter "Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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To find out where you are, GNU Fortran has a GETCWD call link[^] I don't know how standard it is. It doesn't seem to have a corresponding SETCWD call. If you are starting the program using CreateProcess() then you can set the working directory, and I think it will default to the working directory of the calling process if you don't.
Peter "Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
Unfortunately the Absoft compiler is a bit basic and does not have such luxuries. But I must check what I put in CreateProcess. I have to put it all in the command line, maybe I missed the path and it was just luck that it ran where it is.
------------- Bibo ergo sum
-
Yes yes yes! I put the whole path in (without doubling the \) and the test program works. It doesn't work for the original Fortran yet but at least I know where to start. If Fortran is only going to give it 80 chars every time I can see some problems coming up on the target machine, because the paths can get a lot longer. I did try a relative path but it wasn't having it, must try and get Fortran to tell me where it is. In C++ I use _getcwd, can someone tell me how to get it in Fortran? It was giving me IOS=2, which is not in the list of Intel error messages.
------------- Bibo ergo sum
Hi, if pathname length is a concern, you can always "map a network drive" (it works on the local machine too, despite the name), i.e. assign a drive letter to a (deep) subdirectory, allowing you to shorten the pathname considerably. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
-
Luc Pattyn wrote:
I installed Silverfrost F95
nice one Luc - thats dedication !!! 'g'
My very first large apps were coded in Fortran IV, some 30 years ago, but I hadn't done any Fortran work since I switched to C, also long ago. This was an opportunity to read some of the docs, and experiment a bit. :)
Luc Pattyn [Forum Guidelines] [My Articles]
Fixturized forever. :confused:
-
Unfortunately the Absoft compiler is a bit basic and does not have such luxuries. But I must check what I put in CreateProcess. I have to put it all in the command line, maybe I missed the path and it was just luck that it ran where it is.
------------- Bibo ergo sum
-
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?
------------- Bibo ergo sum
Fixed it! I finally ported the old Fortran to Windows and recompiled it. I put some prints in to see what it gets up to. It works. The problem was the Fortran having been compiled under Cygwin, some kind of Linux for Windows. It ran under Windows, but not quite. So when I compiled it myself, it could use the strings to open the file. Just because it runs from the command line does not mean you can embed it and it still runs.