/**

 * asm/decimal.c

 * Copyright (C) 2008 Markus Broeker

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <limits.h>

#define  MAXBITS __WORDSIZE

#define  MAXVALUE ULONG_MAX

typedef unsigned long int ULONG;

void usage (char *name)

{

    printf ("Usage: %s start [end] [base]\n", name);

}

/*

 * Computes the binary representation of a

 * decimal value and returns the result

 * in proper order and the number of digits

 */

char *dec_to_base (ULONG decimal, int base, int *digits)

{

    char *encoded;

    char swp;

    int i;

    i = 0;

    if ((decimal > MAXVALUE)) {

        perror ("VALUE TOO BIG");

        return NULL;

    }

    if ((encoded = malloc ((MAXBITS) * sizeof (char))) == NULL) {

        perror ("MALLOC ERROR");

        return NULL;

    }

    while (decimal > base - 1) {

        encoded[i++] = (decimal % base);

        decimal /= base;

    }

    encoded[i++] = (decimal % base);

    *digits = i;

    for (i = 0; i < *digits - 1; i++) {

        swp = encoded[*digits - i - 1];

        encoded[*digits - i - 1] = encoded[i];

        encoded[i] = swp;

    }

    return encoded;

}

int main (int argc, char **argv)

{

    ULONG decimal, start, end;

    int bits, base, i;

    char *binaer;

    base = 2;

    if (argc == 2) {

        start = atol (argv[1]);

        end = start + 1;

    } else if (argc == 3) {

        start = atol (argv[1]);

        end = atol (argv[2]);

    } else if (argc == 4) {

        start = atol (argv[1]);

        end = atol (argv[2]);

        base = atoi (argv[3]);

    } else {

        usage (argv[0]);

        return EXIT_SUCCESS;

    }

    if (!((start >= 0) && (end > start) && (base > 1))) {

        usage ("Trottel");

        printf ("%ld\t%ld\t%d\n", start, end, base);

        return EXIT_SUCCESS;

    }

    printf ("\tVALUE \t\tDIGITS\t\t Encoded\n");

    printf ("----------------------------------------------------\n");

    for (decimal = start; decimal < end; decimal++) {

        if ((binaer = dec_to_base (decimal, base, &bits)) == NULL) {

            return EXIT_FAILURE;

        }

        printf ("%12ld %12d \t\t", decimal, bits);

        for (i = 0; i < bits; i++) {

            printf ("%X", binaer[i]);

        }

        printf ("\n");

        if (binaer)

            free (binaer);

    }

    return EXIT_SUCCESS;

}