Thread: Simple Pointer Program

I know that there are things on the internet but nothing seems to be helping right now. I am simply trying to reverse this string uses pointers and no strlen or reverse functions from the string library. Can somebody tell me what I am missing?

Code:

#include<stdio.h>

void main()
{
        char*hello = "hello";
        char*reverse(char*str1);
        printf("%c", reverse(hello));
}

char*reverse(char*str1)
{
        int length;
        for(length = 0; str1[length]; ++length);

        char* left  = str1;
        char* right = left + length - 1;
        char tmp;
        while (left < right) {
                tmp = *left;
                *left++  = *right;
                *right-- = tmp;
        }
        return str1;
}

Should the printf() control string be "%c" or "%s"?

"%c" stands for character. "%s" stands for _string_. So the latter one.