shapelib_dump.F90

!    Copyright 2011 Davide Cesari <dcesari69 at gmail dot com>
!
!    This file is part of FortranGIS.
!
!    FortranGIS is free software: you can redistribute it and/or modify
!    it under the terms of the GNU Lesser General Public License as
!    published by the Free Software Foundation, either version 3 of the
!    License, or (at your option) any later version.
!
!    FortranGIS is distributed in the hope that it will be useful, but
!    WITHOUT ANY WARRANTY; without even the implied warranty of
!    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
!    Lesser General Public License for more details.
!
!    You should have received a copy of the GNU Lesser General Public
!    License along with FortranGIS.  If not, see
!    <http://www.gnu.org/licenses/>.

PROGRAM shapelib_dump
use,INTRINSIC :: iso_c_binding
USE shapelib
IMPLICIT NONE

INTEGER,PARAMETER :: lencharattr=40, nshp=4, tshp=shpt_polygonz

TYPE(shpfileobject) :: shphandle
TYPE(shpobject) :: shpobj
INTEGER :: i, j
CHARACTER(len=1024) :: filename

INTEGER :: nshpr, tshpr, nfield, nrec, nd
REAL(kind=c_double) :: minbound(4), maxbound(4)
CHARACTER(len=lencharattr) :: charattrr
INTEGER :: intattrr
REAL(kind=c_double) :: doubleattrr

CALL getarg(1,filename)
IF (filename == '') THEN
  print'(A)','Usage: shapelib_dump <shp_file>'
  stop
ENDIF

! ==== How to read a shapefile ====

! open an exixting shapefile and associate it to a shapefile object
! filename does not include extension
shphandle = shpopen(trim(filename), 'rb')
! error check
IF (shpfileisnull(shphandle) .OR. dbffileisnull(shphandle)) THEN
  print*,'Error opening ',trim(filename),' for reading'
  stop 1
ENDIF

! get general information about the shapefile object
CALL shpgetinfo(shphandle, nshpr, tshpr, minbound, maxbound, nfield, nrec)
print*,'number and type of shapes:',nshpr,tshpr

! read the nshp shapes
DO i = 0, nshpr - 1
  print*,'Checking shape',i
! read the i-th shape from the shapefile object and obtain a shape object
  shpobj = shpreadobject(shphandle, i)
! error check
  IF (shpisnull(shpobj)) THEN
    print*,'Error in shpreadobject',i
    stop 1
  ENDIF

! now access all the components of the shape object
! number of vertices
  print*,'nvertices:',shpobj%nvertices
  IF (ASSOCIATED(shpobj%panpartstart)) THEN
    print*,'nparts:',SIZE(shpobj%panpartstart)
    print*,shpobj%panpartstart
  ENDIF

! destroy the shape object to avoid memory leaks
! notice that for accessing dbf attributes the shape object is not required
  CALL shpdestroyobject(shpobj)

ENDDO

! close the shapefile object
CALL shpclose(shphandle)


END PROGRAM shapelib_dump