We now have an idea of the components involved in a scope. Within a single file, the visibility and extent components are somewhat intertwined and take primary consideration. With multiple files, the linkage component of a scope requires more consideration.
We can think of scope starting from a very narrow range and expanding to the entire program. Block and function scope has the narrowest range. External variables and function prototypes have a wider scope, encompassing an entire file. The broadest scope occurs with the declarations from within a single file and expanded across multiple files.
Some clarification is needed regarding global scope. Global scope means that a function or variable is accessible in two or more source files. It is very often confused with file scope, where a function or variable is only accessible in the single file where it is declared. So, when a programmer refers to a global variable...
