Read this
http://www.eternallyconfuzzled.com/tuts/languages/jsw_tut_pointers.aspx

In case char *name="Yankee Duddle"; string literal turns into an unnamed, static array of characters, and this unnamed array may be stored in read-only memory, and which therefore cannot necessarily...

Syntax
#include <string.h>
void *memset(void *s, int c, size_t n);
Description
memset() sets the first n bytes in memory area s to the value of c (converted to an
unsigned char). It returns s.