Auto Start Vacuum

I have been using makercam.com for some simple gcode generating. I have not found a way to have it insert an M8 into the beginning of the code to turn on the vacuum table.

So, I am looking for some help on writing a script to insert M8 using the FILTERS, or just a way to have the vacuum start with every job that LinuxCNC runs.

Thanks for any help you can provide!

I have a simple script filter that I use on some machines to insert the pre/post-ambles to allow some generic g-code to work on several machines.
The echo lines will be inserted at the beginning and end.Just save the script as something.sh (like pre-post.sh), move it someplace such as your config dir. Change the files permission to make it executable. Then in your ini file under the [FILTER] section add the line ngc = /(path to file loacation)/something.sh

You can also do find and replaces and what ever else you can dream up. A script that just finds one line that you always have at the beginning of the file and adds your M8 code might be even simpler (just a single sed line.)

Thanks. That does exactly what I needed.