Different copy function showing drastically different results

[ilikesuresh]

I have written a program for string copying
when i run this program its give the result fine

main()
{
  char *d="MyString";
  char *s="\0";
  char *p="\0";
   s=(char *)malloc(20);
   P=(char *)malloc(20);
   p=s;
   while(*s++ = *d++);
  printf("%s",p);
}

But when i run

main()
{
  char *d="MyString";
  char *s="\0";
   s=(char *)malloc(20);
   while(*s++ = *d++);
  printf("%s",s);
}

-This way its run fine but it does not display any thing.
Please clarify me what's wrong with the second program?

[Ganon11]

You are incrementing the pointer s, so that by the end of the program, it points past the string you just copied. Thus, it points to no valid text, and no text is displayed. You need a way to get the pointer back to its original position - like in the first example, where you made a second pointer to hold that memory location,