Pointer to Fortran 95 Derived Type

You can show structures, Fortran 95 derived types, and pointers with dbx.

demo% f95 -o debstr -g DebStruc.f95
 demo% dbx debstr
 (dbx) stop in main
 (2) stop in main
 (dbx) list 1,99
     1   PROGRAM DebStruPtr! Debug structures & pointers
Declare a derived type.
     2      TYPE product
     3         INTEGER        id
     4         CHARACTER*16   name
     5         CHARACTER*8    model
     6         REAL           cost
     7         REAL           price
     8      END TYPE product
     9
Declare prod1  and prod2 targets.
    10      TYPE(product), TARGET :: prod1, prod2
Declare curr and prior pointers.
    11      TYPE(product), POINTER :: curr, prior
    12
Make curr point to prod2.
    13      curr => prod2
Make prior point to prod1.
    14      prior => prod1
Initialize prior.
    15      prior%id = 82
    16      prior%name = "Coffee Cup"
    17      prior%model = "XL"
    18      prior%cost = 24.0
    19      prior%price = 104.0
Set curr to prior.
    20      curr = prior
Print name from curr and prior.  
    21      WRITE ( *, * ) curr%name, " ", prior%name
    22   END PROGRAM DebStruPtr
 (dbx) stop at 21
 (1) stop at "DebStruc.f95":21
 (dbx) run
 Running: debstr
(process id 10972)
stopped in main at line 21 in file "DebStruc.f95"
   21      WRITE ( *, * ) curr%name, " ", prior%name
(dbx) print prod1
 prod1 = (
    id = 82
    name = "Coffee Cup"
    model = "XL"
    cost = 24.0
    price = 104.0
)

Above, dbx displays all fields of the derived type, including field names.

You can use structures and inquire about an item of an Fortran 95 derived type.

Ask about the variable
(dbx) whatis prod1
 product prod1
Ask about the type (-t)
 (dbx) whatis -t product
 type product
    integer*4 id
    character*16 name
    character*8 model
    real cost
    real price
 end type product

To print a pointer, type:

dbx displays the contents of a pointer, which is an address. This address can be different with every run.
(dbx) print prior
 prior = (
     id    = 82
     name = ’Coffee Cup’
     model = ’XL’
     cost = 24.0
     price = 104.0
 )