madmax61
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Passing character from gnu C (gcc) to gfortran includes NUL terminator
When passing a character array from gcc to gfortran the string contains the NUL character which terminates the string in C, but not in FORTRAN.
On the HP UNIX system the NUL did not get sent when passing it across, but in the GNU C/Fortran world on Linux it is passed which is causing problems for programs I am trying to convert to Linux.
I can, and have written a subroutine which will strip this NUL so I have a solution, however I believed that by using ISO_C_BINDING and then passing the string that it would not send the NUL across, which would have been a nicer solution.
Do you know if using ISO_C_BINDING from gfortran and then having C/gcc pass the characters that it ought not send the NUL or have I misinterpreted something?
If this is true do you have some working code to show this? I tried it and it still sent the NUL, so I can't see the point in using ISO_C_BINDING and C_CHAR?
(p.s. I am using gcc 4.4.? and in RedHat Linux if that is of any importance.)
Kind Regards,
Max
On the HP UNIX system the NUL did not get sent when passing it across, but in the GNU C/Fortran world on Linux it is passed which is causing problems for programs I am trying to convert to Linux.
I can, and have written a subroutine which will strip this NUL so I have a solution, however I believed that by using ISO_C_BINDING and then passing the string that it would not send the NUL across, which would have been a nicer solution.
Do you know if using ISO_C_BINDING from gfortran and then having C/gcc pass the characters that it ought not send the NUL or have I misinterpreted something?
If this is true do you have some working code to show this? I tried it and it still sent the NUL, so I can't see the point in using ISO_C_BINDING and C_CHAR?
(p.s. I am using gcc 4.4.? and in RedHat Linux if that is of any importance.)
Kind Regards,
Max
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ASKER
As it turns out the NUL character WAS being passed on HP-UX from C to FORTRAN. The difference I was experiencing between Linux and HP-UX was that the NUL character was displaying in the output from the program in vi on our Linux system and not on the HP. In any case I wasn't happy that when a passed string from C when being printed in the GFORTRAN program I was porting across to Linux was printing out this NUL, so I still wanted to resolve this issue.
Again thankyou for the answers, they were exactly the info I required.
Having the BIND and ISO_C_BINDING business is more likely to confuse than assist in this case is my feeling.
Cheers,
Max
Again thankyou for the answers, they were exactly the info I required.
Having the BIND and ISO_C_BINDING business is more likely to confuse than assist in this case is my feeling.
Cheers,
Max
ASKER
Very much appreciated.
Split the points as both answers were just as helpful, even though the same person.
Many thanks.
Cheers,
Max