C 语言 mmap

/*

*@author cody

*@date 2014-08-12

*@description 

*/

/*

#include <sys/mman.h>

void *mmap(void *addr,size_t len,int prot,int flag,int filedes,off_t off);

int munmap(void *addr,size_t len);

*/

#include <stdlib.h>

#include <sys/mman.h>

#include <fcntl.h>



void MmapFile(){

    int *p;

    int fd = open("hello",O_RDWR);

    if(fd <  0){

        perror("open hello");

        exit(1);

    }



    p = mmap(NULL,6,PROT_WRITE,MAP_SHARED,fd,0);

    if(p == MAP_FAILED){

        perror("mmap");

    }



    close(fd);

    p[0] = 0x30313233;

    munmap(p,6);



}





int main(int argc, char const *argv[])

{

    MmapFile();

    return 0;

}