ogr2ogr
Convert Simple Features data between file formats.
TLDR
Convert a Shapefile into a GeoPackage
$ ogr2ogr -f GPKG [output].gpkg [input].shp
Change coordinate reference system of a GeoPackage from EPSG:4326 to EPSG:3857
$ ogr2ogr -s_srs [EPSG:4326] -t_srs [EPSG:3857] -f GPKG [output].gpkg [input].gpkg
Convert a CSV file into a GeoPackage, specifying the names of the coordinate columns and assigning a coordinate reference system
$ ogr2ogr -f GPKG [output].gpkg [input].csv -oo X_POSSIBLE_NAMES=[longitude] -oo Y_POSSIBLE_NAMES=[latitude] -a_srs [EPSG:4326]
Load a GeoPackage into a PostGIS database
$ ogr2ogr -f "PostgreSQL" PG:dbname="[database_name]" [input].gpkg
Clip layers of a GeoPackage file to the given bounding box
$ ogr2ogr -spat [min_x] [min_y] [max_x] [max_y] -f GPKG [output].gpkg [input].gpkg
