/usr/bin/postgis

Unrecognized command: --help
Usage: /usr/bin/postgis <command> [<args>]
Commands:
  help               print this message and exits
  list-all           list all databases
  list-enabled       list PostGIS-enabled databases
  enable <db>...     enable PostGIS in given databases
  upgrade [<db>...]  upgrade PostGIS in given databases (or all)
  status [<db>...]   print PostGIS status in given databases (or all)
  install-extension-upgrades [--pg_sharedir <dir>] [--extension <name>] [<from>...]
    Ensure files required to upgrade PostGIS from
    the given version are installed on the system.
    The <from> arguments may be either version numbers
    or PostgreSQL share directories to scan to find available
    ones.