[GPX] Read all trkpt, and merge into single track?

[Winfried]

Hello,

I need to merge multiple tracks in multiple GPX files that all go in the same direction but aren't in the right order.

Before I figure out how to do it, I was wondering if someone has working code to…

1. Read multiple GPX files, each containing one or more tracks (<trk>),
   
2. Read all the track points they contain (<trkpt>),
   
3. Order them, and
   
4. Save the whole thing into a single track in a single GPX
   

?

Thank you.