/*      $OpenBSD: a64l.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */

#include <errno.h>
#include <stdlib.h>

long
a64l(const char *s)
{
        long value, digit, shift;
        int i;

        if (s == NULL) {
                errno = EINVAL;
                return(-1L);
        }

        value = 0;
        shift = 0;
        for (i = 0; *s && i < 6; i++, s++) {
                if (*s >= '.' && *s <= '/')
                        digit = *s - '.';
                else if (*s >= '0' && *s <= '9')
                        digit = *s - '0' + 2;
                else if (*s >= 'A' && *s <= 'Z')
                        digit = *s - 'A' + 12;
                else if (*s >= 'a' && *s <= 'z')
                        digit = *s - 'a' + 38;
                else {
                        errno = EINVAL;
                        return(-1L);
                }

                value |= digit << shift;
                shift += 6;
        }

        return(value);
}