djb2a hash algorithm

djb2a.c

#include <stdio.h>

unsigned long hash(unsigned char *str) {
        unsigned long hash = 5381;
        int c;
        while ((c = *str++))
                hash = hash * 33 ^ c;
        return hash;
}

int main(int argc, char *argv[]) {
        if (argc < 2)
                return 1;

        printf("hash %ld\n", hash(argv[1]));
        return 0;
}