stdin for LinuxCNC

Yes, if you open your program with Axis you can send to stdout and Axis gets it.

A python example of doing just that

wiki.linuxcnc.org/cgi-bin/wiki.pl?Simple...rators#Arc_Generator

JT

If you use AXIS as your user interface, the program `axis-remote` can remotely open a gcode file. However, it can't open from a pipe since interpreting gcode can involve seeking in the file.

If you want to script loading gcode into AXIS, you are stuck saving it to a temporary file, using axis-remote to open it, and then ensuring that the program still exists on disk until AXIS is done with it.

Probably it would be possible to design a way to make AXIS responsible for cleaning up this temporary file on exit. If you do care to implement such a thing, please file a pull request on github linuxcnc-mirror so that I can review it for possible inclusion in a future version of LinuxCNC.

Possibly you can piggy-back on the existing code for gcode filters to manage the temporary file's lifetime; I don't recall the specifics of how that works.

Is it possible that typing line-by-line in the MDI window achieves the required effect? (It is hard to say, as the reason for wanting to use stin wasn't specified)

A simple Python script could accept stdin and MDI it to the running LinuxCNC instance.
axis-remote can take commands line by line, and might do what is wanted.