WoW API < debugstack

Output a string representation of the current calling stack, similar to the standard Lua debug.traceback() call, which is not present in WoW.

description = debugstack([start[, count1[, count2]]])

Arguments Edit

Parameters Edit

Number - the stack depth at which to start the stack trace (default 1 - the function calling debugstack)
Number - the number of functions to output at the top of the stack (default 12)
Number - the number of functions to output at the bottom of the stack (default 10)

Returns Edit

String - a multi-line string showing what the current call stack looks like

If there are more than count1+count2 calls in the stack, they are separated by a "..." line.

Example Edit

Assume the following example file, "file.lua":

 1: function a()
 2:   error("Boom!"); 
 3: end
 5: function b() a(); end
 7: function c() b(); end
 9: function d() c(); end
11: function e() d(); end
13: function f() e(); end
15: function errhandler(msg)
16:   print (msg .. "\nCall stack: \n" .. debugstack(2, 3, 2));
17: end
19: xpcall(f, errhandler);

This would output something along the following:

file.lua:2: Boom!
Call stack:
file.lua:2: in function a
file.lua:5: in function b
file.lua:7: in function c
file.lua:13: in function f

Example 2 Edit

Combining debugstack with a strmatch can enable you to get the current line of a function call.

 1: function debugprint(msg)
 2:   local line = strmatch(debugstack(2),":(%d):");
 3:   print("Debug Print on Line "..line.." with message: "..msg);
 4: end
 6: function doSomething()
 7:   debugprint("We tried to do something.");
 8: end

This would return the following output from print:

Debug Print on Line 7 with message: We tried to do something.

Note that despite its all-lowercase name, this is not a core Lua function. It is a WoW API.