output to logfile helfulf for debug, especially with MPI

src/DAMASK_interface.f90

@@ -70,9 +70,8 @@ subroutine DAMASK_interface_init
   external :: &
     quit
 
-  print'(/,1x,a)', '<<<+-  DAMASK_interface init  -+>>>'
 
-  if(worldrank == 0) open(OUTPUT_UNIT, encoding='UTF-8')                                            ! for special characters in output
+  print'(/,1x,a)', '<<<+-  DAMASK_interface init  -+>>>'
 
  ! http://patorjk.com/software/taag/#p=display&f=Lean&t=DAMASK%203
 #ifdef DEBUG

src/parallelization.f90

@@ -86,7 +86,18 @@ subroutine parallelization_init
   if (err_MPI /= 0_MPI_INTEGER_KIND) &
     error stop 'Could not determine worldrank'
 
-  if (worldrank == 0) then
+#ifdef LOGFILE
+  write(rank_str,'(i4.4)') worldrank
+  open(OUTPUT_UNIT,file='log.'//rank_str,status='replace',encoding='UTF-8')
+#else
+  if (worldrank /= 0) then
+    close(OUTPUT_UNIT)                                                                              ! disable output
+    open(OUTPUT_UNIT,file='/dev/null',status='replace')                                             ! close() alone will leave some temp files in cwd
+  else
+    open(OUTPUT_UNIT,encoding='UTF-8')                                                              ! for special characters in output
+  endif
+#endif
+
   print'(/,1x,a)', '<<<+-  parallelization init  -+>>>'
 
   call MPI_Get_library_version(MPI_library_version,devNull,err_MPI)
@@ -96,7 +107,6 @@ subroutine parallelization_init
 #ifdef _OPENMP
   print'(1x,a,i0)',      'OpenMP version: ',openmp_version
 #endif
-  end if
 
   call MPI_Comm_size(MPI_COMM_WORLD,worldsize,err_MPI)
   if (err_MPI /= 0_MPI_INTEGER_KIND) &
@@ -121,12 +131,6 @@ subroutine parallelization_init
   if (typeSize*8_MPI_INTEGER_KIND /= int(storage_size(0.0_pReal),MPI_INTEGER_KIND)) &
     error stop 'Mismatch between MPI_DOUBLE and DAMASK pReal'
 
-  if (worldrank /= 0) then
-    close(OUTPUT_UNIT)                                                                              ! disable output
-    write(rank_str,'(i4.4)') worldrank                                                              ! use for MPI debug filenames
-    open(OUTPUT_UNIT,file='/dev/null',status='replace')                                             ! close() alone will leave some temp files in cwd
-  endif
-
 !$ call get_environment_variable(name='OMP_NUM_THREADS',value=NumThreadsString,STATUS=got_env)
 !$ if(got_env /= 0) then
 !$   print'(1x,a)', 'Could not get $OMP_NUM_THREADS, using default'