gary.c

// Implementation of Gary's Formula as described on http://ludix.com/moriarty/psalm46.html
/* v1.1 - slight revision/optimization:
 * inlined get_code() and parse_arg() functions
 * removed excessive multiplication (distributive property)
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>

uint64_t
get_sum(char *arg)
{
    uint64_t sum = 0;

    for(; *arg; arg++)
        sum += isalpha(*arg) ? toupper(*arg) - '@' : 0;

    return sum * 6;
}

void
parse_args(char **args)
{
    for(; *args; args++)
        printf("%s: %lu\n", *args, get_sum(*args));
}

void
usage(void)
{
    fputs("usage: gary <string>\n", stderr);
    exit(1);
}

int
main(int argc, char **argv)
{
    if(argv[1])
        parse_args(argv + 1);
    else
        usage();

    return 0;
}