I have a need for a way to access/read/write data to/from Gnumeric. With exception of below, I have not found any info available for this task. I have a lot of experience with reading and writing data to and from Excel. I would be glad to develop a C API to do so with Gnumeric either as a contribution or as a plugin if there was some technical specs or simple notes available as a way to narrow down the task, as opposed to having to read thru the entire code base to find the source files and functions that pertain to where and how SS data is stored, functions that read the data store to populate a SS, header files needed, just anything along those lines. Such an API would be very useful to me, and if developed, I would take a stab at providing a like Python plugin if one is needed.
For those who are not aware of it, you can find an excellent Python example program provided by Morten Welinder at https://gitlab.gnome.org/GNOME/gnumeric/-/blob/master/test/t3001-introspection-simple.py. It provides the only insights into gnm files I have found so for. It is hard to tell just how extensive the capabilities are from just this one program, but it is a start. I would appreciate any comments or suggestions re. this matter.