K&R exercise 5-4, strend, find string at end of another string

kr5-4.c

#include <stdio.h>

int strend(char *s, char *t);

int strend(char *s, char *t)
{
    //save pointer to the first element of t
    char *start = t;
    //move to the end of each string
    while (*++s)
        ;
    while (*++t)
        ;
    //compare from end to beginning
    while (t > start && *--t == *--s)
        ;
    return start == t;
}

int main()
{
    char ape[] = "what spam";
    char baboon[] = "what spam";
    char chimp[] = "spam";
    char lemur[] = "eggs";
    int what;
    what = strend(ape, baboon);
    printf("%s at end of %s? %d\n",baboon, ape, what);
    what = strend(ape, chimp);
    printf("%s at end of %s? %d\n",chimp, ape, what);
    what = strend(ape, lemur);
    printf("%s at end of %s? %d\n",lemur, ape, what);
    return 0;
}

// This is buggy, does not match if a == b... hmmm

Fixed now. The loop (*--t == *--s) would continue before the start of the character array and by chance (or not) would always return 0 for a certain while so that it under-ran the start variable.

Actually this could be made more optimal if I compared t with start rather than *t and *s > 0.

Even better, do the comparison to start first, then it will stop the underflow, and remove the need for t++ before the return.