C Program Structure - C Functions

Syntax:
filename.h:	Module interface
return_type function_name2( type arg1, type arg2, ... );   extern type variable2; /*external declaration*/	Public function prototype   External declaration
filename.c:
#include <filename2.h> #include "filename.h"   type variable1; type variable2;   return_type function_name1( type arg1, type arg2, ... );   main( ) {     :     return 0; }   return_type function_name1( type arg1, type arg2, ... ) {     :     return expression; }   return_type function_name2( type arg1, type arg2, ... ) {     :     return expression; }	Header files     Module variables definitions   Local function prototype   Main function - start running here.           Module function
Example:
my_module.h:
typedef enum days {     sunday,     monday,     tusday } T_DAY;   #define NUM 100 extern T_DAY x[NUM];   /* Module's interface functions -     to be called from other modules */ void Set_X(); void Get_X();
my_module.c:
#include <stdio.h> #include "my_module.h"   T_DAY x[NUM]; int n; char c;   int Calc_X();   void Set_X() {    ... }   void Get_X() {    ... }   int Calc_X() {    ... }
main.c:
#include <stdio.h> #include "my_module.h"   main() {     int x;       Set_X();     x = Get_X();       printf("x value=%d", x);     return 0; }