Creating your own header file in C

Question

Can anyone explain how to create a header file in C with a simple example from beginning to end

User · Answer

myfile h   ifndef  myfile h  define  myfile h  void function      endif   myfile c   include  myfile h   void function

User · Answer

ifndef MY HEADER H   define MY HEADER H    put your function headers here   endif   MY HEADER H serves as a double-inclusion guard   For the function declaration  you only need to define the signature  that is  without parameter names  like this   int foo char      If you really want to  you can also include the parameter s identifier  but it s not necessary because the identifier would only be used in a function s body  implementation   which in case of a header  parameter signature   it s missing   This declares the function foo which accepts a char  and returns an int   In your source file  you would have    include  my header h   int foo char  name         do stuff    return 0

User · Answer

header files contain prototypes for functions you define in a  c or  cpp  cxx file  depending if you re using c or c     You want to place  ifndef  defines around your  h code so that if you include the same  h twice in different parts of your programs  the prototypes are only included once    client h   ifndef CLIENT H  define CLIENT H  short socketConnect char  host unsigned short port char  sendbuf char  recievebuf  long rbufsize      endif     CLIENT H      Then you d implement the  h in a  c file like so   client c   include  client h   short socketConnect char  host unsigned short port char  sendbuf char  recievebuf  long rbufsize     short ret   -1     some implementation here  return ret

User · Answer

foo h   ifndef FOO H       Include guard     define FOO H   int foo int x       An example function declaration      endif    FOO H    foo c   include  foo h      Include the header  not strictly necessary here      int foo int x        Function definition          return x   5      main c   include  lt stdio h gt   include  foo h      Include the header here  to obtain the function declaration     int main void        int y   foo 3       Use the function here        printf   d n   y       return 0      To compile using GCC  gcc -o my app main c foo c

[c] Creating your own header file in C

Examples related to c

Examples related to header

Examples related to include

Examples related to include-guards

Examples related to c-header