If you want to share several functions or variables in several files maitaining the consistency how would you share it?

To maintain the conistency between several files firstly place each definition in '.c' file than using external declarations put it in '.h' file after it is included .h file we can use it in several files using ‪#‎include‬ as it will be in one of the header files, thus to maintain the consistency we can make our own header file and include it where ever needed.