A interesting problem of C programming

["Wang Yu" <wangyuict@xxxxxxxxx>]

Hi, all
I have the following code:
#include <stdio.h>                                                                                                                                                                                                                                   
int main()                                                                                                                                 
{                                                                                                                                          
                                                                                                                                           
    char *p;                                                                                                                               
    p = 0;                                                                                                                                 
    printf("%s", p);                                                                                                                       
    printf("\n");                                                                                                                          
    return 0;                                                                                                                              
}

The out put is (null)
But, if I change into:

#include
<stdio.h>                                                                                                                        
                                                                                          
int
main()                                                                                                                                
{                                                                                                                                         
                                                                                                                                          
    char
*p;                                                                                                                              
    p =
0;                                                                                                                                
    printf("%s\n",
p);                                                                                                                      
                                                                                                                   
    return
0;                                                                                                                             
}

The output will be Segment fault!

I don't know why....
Thanks!
-- 
National Research Center for Intelligent Computing Systems
Institute of Computing Technology, Chinese Academy of Sciences