You can use Geo::GDAL::FFI to read the contents of a geopackage (untested example code below). The geometry field is stored as Well Known Binary (WKB), or perhaps a variant of it. This can be converted to Well Known Text (WKT) to be human readable.

A definition of WKB is given in the libgeos docs at https://libgeos.org/specifications/wkb, and WKT at https://libgeos.org/specifications/wkt/.

The GDAL stack can be a beast to install if the aliens have to compile everything from source (GDAL, Proj, GEOS, libtiff, libsqlite3, optionally also spatialite, freexl and curl). If you are on a unix type machine then install the gdal-dev package using your system package manager, then the GDAL aliens will run system installs.

Example code:

#  adapted from the Geo::GDAL::FFI docs, untested
my $layer_name = 'some_layer';
my $db = Open('test.gpkg');
my $layer = $dataset->GetLayer($layer_name);
$layer->ResetReading;
while (my $feature = $layer->GetNextFeature) {
    my $value = $feature->GetField('name');
    my $geom = $feature->GetGeomField;
    say $value, ' ', $geom->AsText;
}

[download]

Update: More details of the geopackage geometry format are at http://www.geopackage.org/spec131/index.html#gpb_format. This should be of use if you decide to write your own parser to extract the first and last coordinates of each linestring.

In reply to Re: Geo Package files by swl
in thread Geo Package files by Bod

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