行为的封装

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct node{
errno_t  (*fp_strcpy_s)(char * ,  rsize_t ,  const char * );
size_t   (*fp_strlen)( const char * );
int      (*fp_strcmp)( const char * ,  const char * );

}stringutil;
stringutil g_string={strcpy_s,strlen,strcmp};

int main(){
char a[20];
char b[10]="nihaodsd";
printf("%d\n",g_string.fp_strlen("nihao"));
printf("%d\n",g_string.fp_strcmp("aaa","aaa"));
printf("%d\n",g_string.fp_strcpy_s(a,g_string.fp_strlen(b)+1,b));

printf("%s\n",a);
return 0;

}