Question

C functions are typically split into header files ( .h ) where things are declared but not defined, and implementation files ( .c ) where they are defined. When we run the C compiler, a complex sequence of events is triggered with the usual successful outcome begin an executable file as illuatrated at http://www.codingunit.com/

Compilation process

The preprocessor merges the contents of the header and implementation files, and also expands any macros. The compiler then translates these into low level object code ( .o ) for each file, and the linker then joins together the newly generated object code with pre-compiled object code from libraries to form an executable. Sometimes we just want to generate object code and save it as a library (e.g. so that we can use it in Python).