In this chapter, we'll explore the functions used internally by RPM. These functions are available for anyone to use, making it possible to add RPM functionality to new and existing programs. Rather than continually refer to "the RPM library" throughout this chapter, we'll use the name of the library's main include file — rpmlib.
There are a number of files that make up rpmlib. First and foremost, of course, is the rpmlib library, librpm.a. This library contains all the functions required to implement all the basic functions contained in RPM.
The remaining files define the various data structures, parameters, and symbols used by rpmlib:
rpmlib.h
dbindex.h
header.h
In general, rpmlib.h will always be required. When using rpmlib's header-related functions, header.h will be required, while the database-related function will require dbindex.h. As each function is described in this chapter, we'll provide the function's prototype as well as the #include statements the function requires.