+
−"""
+
−  This utility module is for obtaining information about the PostGIS
+
−   installation.
+
−
+
−  See PostGIS docs at Ch. 6.2.1 for more information on these functions.
+
−"""
+
−import re
+
−
+
−def _get_postgis_func(func):
+
−    "Helper routine for calling PostGIS functions and returning their result."
+
−    from django.db import connection
+
−    cursor = connection.cursor()
+
−    cursor.execute('SELECT %s()' % func)
+
−    row = cursor.fetchone()
+
−    cursor.close()
+
−    return row[0]
+
−
+
−### PostGIS management functions ###
+
−def postgis_geos_version():
+
−    "Returns the version of the GEOS library used with PostGIS."
+
−    return _get_postgis_func('postgis_geos_version')
+
−
+
−def postgis_lib_version():
+
−    "Returns the version number of the PostGIS library used with PostgreSQL."
+
−    return _get_postgis_func('postgis_lib_version')
+
−
+
−def postgis_proj_version():
+
−    "Returns the version of the PROJ.4 library used with PostGIS."
+
−    return _get_postgis_func('postgis_proj_version')
+
−
+
−def postgis_version():
+
−    "Returns PostGIS version number and compile-time options."
+
−    return _get_postgis_func('postgis_version')
+
−
+
−def postgis_full_version():
+
−    "Returns PostGIS version number and compile-time options."
+
−    return _get_postgis_func('postgis_full_version')
+
−
+
−### Routines for parsing output of management functions. ###
+
−version_regex = re.compile('^(?P<major>\d)\.(?P<minor1>\d)\.(?P<minor2>\d+)')
+
−def postgis_version_tuple():
+
−    "Returns the PostGIS version as a tuple."
+
−
+
−    # Getting the PostGIS version
+
−    version = postgis_lib_version()
+
−    m = version_regex.match(version)
+
−    if m:
+
−        major = int(m.group('major'))
+
−        minor1 = int(m.group('minor1'))
+
−        minor2 = int(m.group('minor2'))
+
−    else:
+
−        raise Exception('Could not parse PostGIS version string: %s' % version)
+
−
+
−    return (version, major, minor1, minor2)