Generalize `test_read_snapshot` to several SHPC

Generalize `test_read_snapshot` to accept several SHPC onthe command line.

Overlap/Tests/test_read_snapshot.f90

@@ -16,8 +16,9 @@ program test_read_snapshot
 
   character(len = :), allocatable:: shpc_dir
   type(snapshot) s
-  TYPE(shpc) hshp
-  integer copy, unit, k
+  TYPE(shpc), allocatable:: hshp(:) ! (n_shpc)
+  integer copy, unit, k, i
+  integer n_shpc ! number of input SHPC directories
 
   real:: corner_deg(2) = [0.125, - 59.875]
   ! longitude and latitude of the corner of the whole grid in input
@@ -39,10 +40,19 @@ program test_read_snapshot
 
   !-------------------------------------------------------------------------
 
-  call get_command_arg_dyn(1, shpc_dir, "Required argument: SHPC-directory")
+  n_shpc = COMMAND_ARGUMENT_COUNT()
+  call assert(n_shpc /= 0, &
+       "Required arguments: SHPC-directory [SHPC-directory] ...")
+  allocate(hshp(n_shpc))
 
+  do i = 1, n_shpc
+     call get_command_arg_dyn(i, shpc_dir)
+     call shpc_open(hshp(i), trim(shpc_dir), pszaccess = "rb")
+  end do
+
+  ! Assuming grid_nml.txt is the same in all input SHPC:
   call new_unit(unit)
-  open(unit, file = shpc_dir // "/grid_nml.txt", status = "old", &
+  open(unit, file = hshp(1)%dir // "/grid_nml.txt", status = "old", &
        action = "read", position  = "rewind")
   read(unit, nml = grid_nml)
   close(unit)
@@ -55,19 +65,20 @@ program test_read_snapshot
        "test_read_snapshot dist_lim")
   copy = merge(dist_lim, 0, periodic)
 
-  call shpc_open(hshp, trim(shpc_dir), pszaccess = "rb")
-
   ! main_nml:
-  k = hshp%d0
+  k = hshp(1)%d0
   write(unit = error_unit, nml = main_nml)
   write(unit = error_unit, fmt = *) "Enter namelist main_nml."
   read(unit = *, nml = main_nml)
   write(unit = *, nml = main_nml)
 
-  call read_snapshot(s, [hshp], nlon, nlat, k, &
+  call read_snapshot(s, hshp, nlon, nlat, k, &
        corner = corner_deg * deg_to_rad, step = step_deg * deg_to_rad, &
        copy = copy)
-  CALL shpc_close(hshp)
+
+  do i = 1, n_shpc
+     CALL shpc_close(hshp(i))
+  end do
 
   call write_snapshot(s, corner_deg, step_deg, nlon, nlat, copy, k)