Support exporting cave names from survexport --gpx --entrances

[Philip Withnall]

If using survexport --gpx --entrances, it would be nice to end up with GPX points which are not just a survey station name. For example, if I export a GPX file of all the cave entrances on the Löser plateau, it would be useful to be able to search that GPX file for ‘balcony’ or ‘balkon’ to find the Balkonhöhle entrance, rather than having to remember that its kataster number is 264 and searching for that.

Implementing this might require extending the .svx format to be able to associate more metadata with a cave entrance.

I’m currently using survexport 1.2.35.

[Olly Betts]

(BTW, it's "Loser" (no umlaut): ​https://de.wikipedia.org/wiki/Loser)

It's a good point, though quite a lot needs doing to make it happen.

This would need station descriptions supporting in the .svx file (which is something that would be useful anyway), and the .3d format to include that information.

I think this information probably wants to go in the "comment" field (GPX <cmt> tag) as that typically has a longer length limit in GPS units - which typical station names are well within the name length limit, but a longer cave name might not fit. Not sure what happens if you try to read a file with a longer name in. Maybe the unit truncates, or maybe we would need to, but either way then we'd have to worry about collisions between truncated names.

For CUCC purposes, a script to take the generated GPX file and "mail merge" in the cave names from the troggle data as comments would probably be feasible as a shorter-term solution, and would be a useful prototype for checking how well this actually works in commonly used GPS units.