Programming

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>

int main(void)

{
  int fd = -1;
  void *pa = NULL;
  void *addr = NULL;
  addr=0x10000;
  printf("addr is %p\n",addr);
  size_t len = 0;
  int prot = PROT_READ;
  int flag;
  off_t off = 0;
  long page_size = sysconf(_SC_PAGE_SIZE);
  len = 2 * page_size;
  off= (off_t)addr-page_size;

    if((fd = open("/bin/ls",O_RDONLY,0 )) < 0){
        printf("File open failed\n");
    }

  flag = MAP_SHARED;
  pa = mmap (addr, len, prot, flag, fd, off);
  printf("err is %d\n",errno);
  printf("len is %d\n",len);
  printf("off is %d\n",off);
  printf("add is %d\n",addr);
  close(fd);
}