variable declaration in library

This is a discussion on variable declaration in library within the C Programming forums, part of the General Programming Boards category; Hi all, I assume that the variables meant to be used within a library should be declared static so as ...

  1. #1
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    variable declaration in library

    Hi all,

    I assume that the variables meant to be used within a library should be declared static so as to restrict there scope and prevent their access in the programs using the library.

    Now if my library is being compiled from two c files and am using a global variable in both of them, is there a way to do this without declaring the variable extern? i.e I would like to use the variable in two c files and still have the its scope restricted to the library only. Is there a standard way to do this?


    Thank you

  2. #2
    ATH0 quzah's Avatar
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    Use static functions to access the variable, and don't access it directly. That's pretty much the only way you're going to be able to it without using extern. Hide a static variable inside a function. Use other functions in your library to set or get it.


    Quzah.
    Hope is the first step on the road to disappointment.

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    but how does that solve the problem? I still would not be able to access the same static function from other file....
    could you elaborate your point further, if I am wrong?

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    could you use a header file that holds static getter/setter functions for the variable(s) you need, and include it in the two c files?

  5. #5
    ATH0 quzah's Avatar
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    Code:
    /* publicheader.h */
    void set( type t );
    type get( void );
    Make a header to access your library variables. Include it wherever you want to be able to use your library.
    Code:
    /* library.c */
    static type getset( type t, int s )
    {
        static type x;
        if( s )
            x = t;
    
        return x;
    }
    
    void set( type t )
    {
        getset( t, 1 );
    }
    
    type get( void )
    {
        return getset( 0, 0 );
    }
    There you go.

    Quzah.
    Hope is the first step on the road to disappointment.

  6. #6
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    thank you guys....
    i think i got the idea

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