Pointer to Fortran Derived Type

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You can show structures, Fortran 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
)

In the previous example, dbx displays all fields of the derived type, including field names.

You can use structures and inquire about an item of a Fortran 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:

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
 )