Increment char pointer

I guess you are trying to do something like this..

const char *tmp = "Hello world. This is a great test";
   int count = strlen(tmp);
   while(count>0)
   {
      printf("%s\n",tmp);
      tmp++;
      count--;
   }

I think none of the answers fully answered op's question: op wanted to dereference 'h' to 'i', and he also wanted to know the reason that segmentFault came from his first code snippet

Combined above answers/comments, I list a full answer here:

A. op's first confusion comes from the concept difference between char s[] and char *s:

char *s="hello"; is to place "hello", the string literal, in the read-only memory and make s as a pointer to this string literal, making any writing operation illegal. While if define :

char s[]="hello"; is to put string literal in read-only memory and copy that string to another allocated memory on the stack, so that you can read/write directly on the stack memory (still, you are not touching read-only memory).

So dereference to char *test will given you a constant char, which is the first letter of a string literal located on read-only memory, that's the reason trying to char a = (*tester)++ will fail, because this is a pointer operation on read-only memory, the behavior is undefined.

B. why the second code snippet works ?

writing a = *tester; means you declare another variable char a, then on stack memory, allocate some space for a char and initialize its value to be 'h' ; This is equivalently to have below:

char a;
a = 'h';

Of course you can increment a.

Here is the example to the explicitly print out the address : run link

#include <stdio.h>

int main()
{
    char * tester = "hello";
    printf("tester first  letter address=%p\n",  tester);       // print out address should be something like 0x400648
    printf("tester second letter address=%p\n", (tester+1));    // print out address should be something like 0x400649

    char a;
    a = *tester;
    printf("a address=%p\n", &a);                               // print out address should be something like 0x7ffe0bc6aab7
    a++;        
    printf("a address=%p\n", &a);                               // print out address should be something like 0x7ffe0bc6aab7

    return 0;
}

 char *tester = "hello";

you are trying to create a pointer directly to a string here. which will result to unexpected behaviour(because its a read only space)

instead, what I would suggest you is to use character array.