/**@author cody*@date 2014-08-12*@description *//*#include 
     
      void *mmap(void *addr,size_t len,int prot,int flag,int filedes,off_t off);int munmap(void *addr,size_t len);*/#include 
      
       #include 
       
        #include 
        
         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;}