i have reqwest from several clients that ask me to add script that will run over the gcode file before start ,and if there some dangerous steps(like z in minus more then....) will stop or give alarm...
is that can be done inside mach with lua ? or i must close the file load it on external app(like c#) check and then open again the file in mach if all ok
thanks

The Module Works plugin will do collision detection, etc...  You might be able to write a LUA wizard or script that uses the MachAPI to do what you want to do.  But the Module Works was designed with this kind of task in mind.  However, you and your clients will have to learn to use the tool as you need to do a lot of tool table setups to more fully describe the tools, etc...

Steve