This is no longer a part of the World of Warcraft API. It was removed in patch 1.3.0.

Returns the direction in which the unit is facing (counterclockwise radians, 0 at North)

orientation = UnitFacing(unit);

Arguments

unit 

String - the UnitId of the unit whose orientation you wish to query.

Returns

orientation

orientation 

Number - the current orientation (counterclockwise radians, 0 at north) of the specified unit

Example

local dir = UnitFacing("player");
local dir2 = UnitFacing("target");
ChatFrame1:AddMessage('player orientation: ' .. dir);
ChatFrame1:AddMessage('target orientation: ' .. dir2);

Result

Prints the player's and target's orientation to the chat frame as

'player orientation: 3.112' and 'target orientation: 0.112'.