grafana agent 整合tempo 試用
阿新 • • 發佈:2021-01-07
技術標籤:函式指標
函式指標
1.函式指標
/********************************
*函式指標
********************************/
#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(); /*宣告一個函式*/
int (*p) (); /*定義一個函式指標*/
int main()
{
/**instance analysis1 簡單的例子**/
p = Func; /*將Func函式的首地址賦給指標變數p*/
p();
/**instance analysis1 根據核心仿寫**/
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;
}