Debug.sethook

Available since: Gideros 2011.6
Class: debug

Description

Sets the given function as a hook. The string mask and the number count describe when the hook will be called. The string mask may have the following characters, with the given meaning:

"c": the hook is called every time Lua calls a function; "r": the hook is called every time Lua returns from a function; "l": the hook is called every time Lua enters a new line of code.

With a count different from zero, the hook is called after every count instructions. 

When called without arguments, debug.sethook turns off the hook. 

When the hook is called, its first parameter is a string describing the event that has triggered its call: "call", "return" (or "tail return", when simulating a return from a tail call), "line", and "count". For line events, the hook also gets the new line number as its second parameter. Inside a hook, you can call getinfo with level 2 to get more information about the running function (level 0 is the getinfo function, and level 1 is the hook function), unless the event is "tail return". In this case, Lua is only simulating the return, and a call to getinfo will return invalid data.

 debug.sethook(hook,mask,count)

Parameters

hook: (function) function to be executed as hook
mask: (string) mask of the hook "c", "r" or "l"
count: (number) hook count optional