File driven post processing

[m_beischer]

It would be very nice if there was a function that could read a file (unique to every board) that controls the generation of production files.

The reason for having such function is:
- This is a very important step and it should not be done manually (more than once).
- When changing an old design it is desireble to be able to regenerate the manufacturing data with the same settings.

The file could contain:
#Gerber settings, PCB manufacturing data
- Layers to generate
- Gerber format and other settings that can be done manually
- Settings for drill file

#Printing and circuit board manufacturing data
- Layers to generate for printing
- Format and other stuff

#Other settings
- Output directory
- Naming conventions etc.

[Jon Neal (reportingsjr)]

Marking as duplicate since "technology files" as eagle calls them cover most of this.