Allow write_gcode to provide a preamble and postamble, or allow export_gcode to write to a file

[Todd Stellanova]

From the Shell Command Reference, there appear to be two ways to export gcode from a particular geometry object:

• write_gcode allows writing gcode to a file, but does not allow a prefix or suffix to be set
• export_gcode allows a preamble and postable to be set, but only writes to the console

I would like to write gcode to a file with a preamble and postamble. Perhaps there's a straightforward way to reroute write_gcode to a file with Tcl? I don't see how to do it with the documented command language.

[Juan Pablo Caram]

Since 93e2d95 you can do:

set pre "Hello World!\nI'll be back"
set post "Bye!"
write_gcode my_gcode_object /tmp/output.gcode -preamble $pre -postamble $post