Package libxls

Read binary Excel files from C/C++

https://github.com/libxls/libxls

This is libxls, a C library for reading Excel files in the old binary OLE
format, plus a command-line tool for converting XLS to CSV (named,
appropriately enough, libxls2csv).

General Commands
Command Description
libxls2csv convert binary Excel (.xls) files to CSV