GEOPOS key [member [member ...]]
Time complexity: O(N) where N is the number of members requested.
ACL categories: @read, @geo, @slow
Return the positions (longitude, latitude) of all the specified members of the geospatial index represented by the sorted set.
Given a sorted set representing a geospatial index, populated using the
GEOADD command, it is often useful to obtain back the coordinates of specified members.
When the geospatial index is populated via
GEOADD the coordinates are converted into a 52 bit Geohash,
so the coordinates returned may not be exactly the ones used in order to add the elements, but small errors may be introduced.
The command can accept a variable number of arguments, so it always returns an array of positions even when a single element is specified.
Array reply, specifically:
The command returns an array where each element is a two elements array representing longitude and latitude (x,y) of each member name passed as argument to the command.
Non-existing elements are reported as NULL elements of the array.
dragonfly> GEOADD Sicily 13.361389 38.115556 "Palermo" 15.087269 37.502669 "Catania"
dragonfly> GEOPOS Sicily Palermo Catania NonExisting
1) 1) "13.36138933897018433"
2) 1) "15.08726745843887329"