[Bug libfortran/20179] cannot mix C and Fortran I/O

[fxcoudert at gcc dot gnu dot org]

------- Additional Comments From fxcoudert at gcc dot gnu dot org  2005-09-10 16:06 -------
Looking at that again, it is clear that there is a bug in the way libgfortran
handles pre-connected units. In short, the fd-based I/O library behaves like it
is the first program to access the file; this is not right for pre-connected
units. First example:

$ cat b.c    
extern void foo_(void);
int main ()
{
  write (1, "Hello world\n", 13);
  foo_ ();
  return 0;
}
$ cat b.f
      subroutine foo
      write (*,"(A)") "Ciao world!"
      end
$ ./b.out 
Hello world
Fortran runtime error: End of record


$ cat a.sh                                      
#!/bin/sh
${*} a.f
echo Before
./a.out
echo After
$ cat a.f 
      print *, "foo"
      end
$ ./a.sh ./debug/irun/bin/gfortran -static > foo && cat foo
 foo
After
$ ./a.sh ./debug/irun/bin/gfortran -static                 
Before
 foo
After

>From the strace, the problem is quite clear: fd_truncate is called on the fd #1
(stdout), when the unit is opened.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20179