The InfluxDB C client library is a tool for capturing operating system performance statistics and saving them to InfluxDB, an open-source time series database. The library provides functions for connecting to InfluxDB, handling tags, measurements, and data types such as integers, doubles, and strings. It also includes features like sub-measurements for handling multiple resources of the same type. The library is written in C and can be used to create a data collector program or integrated into an existing application. It has been tested on various operating systems and hardware configurations and provides debugging output options. The code and example usage are available on GitHub, along with documentation and instructions for compiling and using the library.