Re: A interesting problem of C programming

[shreeram <rs.shreeram@xxxxxxxxxxxxx>]

Hi

Trying to dereference a NULL pointer gives you a segmentation fault. Do not try to do this in kernel space. Doing so will lead to kernel panic.

Wang Yu wrote:

Hi, all
I have the following code:
#include <stdio.h>                                                                                                                                                                  &nb sp;                                                              
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

-- 

Regards,
R.S.Shree Ram
GDA Technologies Ltd.