linux系统里面sizeof的问题 -做一纪录


#include <stdio.h>

#define __PACKED_ATTR __attribute__ ((__packed__))

 

typedef struct {

        char p[3] __PACKED_ATTR; //0 1 2


        long i __PACKED_ATTR; //3 4 5 6


} test ; //7


 

typedef struct {

        char p[3]; //0 1 2


        long i; //4 ..7


} test1; //8


int main()
{
    printf("sizeof(test)=%d\n"
            "sizeof(test1)=%d\n",sizeof(test),
            sizeof(test1) );
           
    return 0;

}


/*
result is

sizeof(test)=7
sizeof(test1)=8


*/