GDAL/OGR - Swig - Perl

Installation

This is one possible way to install the gdal and ogr libraries and the perl bindings, with a focus on the latter and working on a Linux. Starting in the gdal directory run

./configure
make
make install
cd swig/perl
running 'make generate' here is suggested
make build
make install

Notes:

* The wrappers (*_wrap.cpp files) may be rebuilt (swig is required) with the command

make generate

before "make build". In some cases "make veryclean" needs to be run prior to "make generate".

* Turning on debug in ./configure:

export CFG=debug; ./configure

Running the test code

make test

Notes:

* The test code is not very verbose. In the case of unexpected behavior, you may want to run the test in verbose mode:

make test VERBOSE=1

* The test can be run even without installing GDAL itself (this works in Linux, I'm not sure about other environments):

export LD_LIBRARY_PATH=../../.libs; make test

Using the modules

The main documentation of the modules are generated from the pods:
gdal
gdalconst
ogr
osr

Example: creating a vector data set

I used this code to import a GPS track, which I created with GPS::NMEA, into PostGIS.

use ogr;
my $datasource = ogr::Open('PG:dbname=gps', 1);
my $layer = $datasource->CreateLayer('track');
my $schema = $layer->GetLayerDefn();
my $feature = new ogr::Feature($schema);
$geometry = new ogr::Geometry($ogr::wkbLineString);
while (<STDIN>) {
 chomp;
 s/^\(//;
 s/\)$//;
 my @l = split(/,/);
 for ($l[2],$l[4]) {
 my $i = int;
 $_ = $i + ($_-$i)/0.6;
 }
 $geometry->AddPoint($l[4],$l[2]);
}
$feature->SetGeometry($geometry);
$layer->CreateFeature($feature);
$layer->SyncToDisk;