------- Additional Comments From fxcoudert at gcc dot gnu dot org 2005-04-15
13:48 -------
First: using stdio in a mixed Fortran/C is a small nightmare. For short term
purposes, I strongly suggest you use the GFORTRAN_STDIN_UNIT=-1 trick. That does
exactly what you want (that is, suggest that Fortran runtime library should not
mess with standard input).
Now, an intersting thing for wandering bug-fixers is that you can mix c and
fortran standard input if you disable preconnection and manually open
/proc/self/fd/0 to unit 5:
$ cat test.c
#include <stdio.h>
void foo_(void)
{
char buf[1024];
while(1) {
if(fgets(buf, 1024, stdin) == NULL) break;
printf("%s", buf);
}
}
$ gcc -c test.c
$ cat test1.f
external foo
character*70 c
read (*,'(A)') c
print *, c
print *, 'calling the C routine'
call foo
print *, 'end of the program'
end
$ cat test2.f
external foo
character*70 c
open (5, file='/proc/self/fd/0')
read (*,'(A)') c
print *, c
print *, 'calling the C routine'
call foo
print *, 'end of the program'
end
$ gfortran test1.f test.o
$ ./a.out < test.c
#include <stdio.h>
calling the C routine
end of the program
$ gfortran test2.f test.o
$ GFORTRAN_STDIN_UNIT=-1 ./a.out < test.c
#include <stdio.h>
calling the C routine
#include <stdio.h>
void foo_(void)
{
char buf[1024];
while(1) {
if(fgets(buf, 1024, stdin) == NULL) break;
printf("%s", buf);
}
}
end of the program
So, the question is: what is the difference between preconnection and manually
openning the unit? I did strace the two processes and I attach the diff of these
traces here (about 50 lines, easy to read). I think the solution to this problem
is here.
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2005-04-10 10:38:34 |2005-04-15 13:48:43
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20788
