函数指针

1.函数指针

/********************************
*函数指针
********************************/

#include <stdio.h>

static int first_drv_open()
{
    printf("first_drv_open\n");
    return 0;
}

static int first_drv_read()
{
    printf("first_drv_read\n");
    return 0;
}

struct file_operations_imitative {
        int       (*open) ();
        int       (*read) ();
        int       (*write) ();
};

int Func();   /*声明一个函数*/
int (*p) ();  /*定义一个函数指针*/

int main()
{
    /**instance analysis1 简单的例子**/
    p = Func;          /*将Func函数的首地址赋给指针变量p*/
    p();

    /**instance analysis1 根据内核仿写**/
    struct file_operations_imitative my_operation;
    my_operation.open = first_drv_open;
    my_operation.read = first_drv_read;

    my_operation.open();
    my_operation.read();

    return 0;
}

int Func()
{
    printf("%s %d\n",__FUNCTION__, __LINE__);
    return 0;
}