zero sized allocation using malloc

int main()  
{  
    int \*p \= 0;  
    printf("before addr: %pn", p);  
    p \= (int \*) malloc(0);  
    printf("after addr: %pn", p);  
    printf("sizeof: %un", sizeof(\*p));  
    \*p \= 1;  
    printf("\--- %d -- this is the last statment.n", \*p);  
    free(p);  
}

Output
before addr: (nil)
after addr: 0x80496c8
sizeof: 4
-– 1 – this is the last statment.

Note :
Linux

allows a ‘read’ of the zero sized allocated memory
allows a ‘write’ on the zero sized allocated memory
sizeof shows an allocation of 4 bytes.

See also