NAME

lua_sethook — sets the debugging hook function, function indicator [-0, +0, -]

SYNOPSIS

#include <fcntl.h>

int
lua_sethook(lua_State *L, lua_Hook f, int mask, int count);

DESCRIPTION

lua_sethook() sets the debugging hook function.

Argument f is the hook function. mask specifies on which events the hook will be called: it is formed by a bitwise or of the constants LUA_MASKCALL, LUA_MASKRET, LUA_MASKLINE, and LUA_MASKCOUNT. The count argument is only meaningful when the mask includes LUA_MASKCOUNT. For each event, the hook is called as explained below:

The call hook:

is called when the interpreter calls a function. The hook is called just after Lua enters the new function, before the function gets its arguments.

The return hook:

is called when the interpreter returns from a function. The hook is called just before Lua leaves the function. You have no access to the values to be returned by the function.

The line hook:

is called when the interpreter is about to start the execution of a new line of code, or when it jumps back in the code (even to the same line). (This event only happens while Lua is executing a Lua function.)

The count hook:

is called after the interpreter executes every count instructions. (This event only happens while Lua is executing a Lua function.)

A hook is disabled by setting mask to zero.

SEE ALSO

Roberto Ierusalimschy, Luiz Henrique de Figueiredo, and Waldemar Celes, Lua 5.1 Reference Manual.

HISTORY

The lua_sethook() manual page is based on Lua Reference Manual 5.1 and was created by Sergey Bronnikov.