Example of using function pointers (refer to linux-kernel code)

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http://blog.csdn.net/xhz1234/article/details/36635083

Xu Hongzhi

Recently read the linux-kernel code, found that a lot of places use function pointers, so you write an example program, for reference:

#include <stdlib.h> #include <stdio.h> #define AddOne 0#define minusone 1#define S_OK 0#define s_err-1typedef Int (*DIR_FN) (int *data); function pointer//actual function 1int add_func (int *data) {(*data) ++;return S_OK;} The actual function 2int minus_func (int *data) {(*data)--;return S_OK;} Core: According to the parameter cmd, get the corresponding FUNCDIR_FN lookup_ctl (int cmd) {DIR_FN fn = null;switch (cmd) {case ADDONE:FN = Add_func;break;case MINUSONE:FN = Minus_func;break;default:break;} return fn;} int main (void) {int data = 100;int cmd = -1;DIR_FN fn = null;printf ("Input the cmd<0 Add, 1 minus>\n"); scanf ("%d", &A Mp;cmd); fn = Lookup_ctl (cmd), fn (&data);p rintf ("Result is:%d\n", data); return 0;}

This article has xhz123 (Xu Hongzhi) to write, reprint please indicate source.

Xu Hongzhi