mdw@git.distorted.org.uk Git - catacomb/blob - progs/fibonacci.c

   1 /* -*-c-*-
   2  *
   3  * Example Fibonacci number computation
   4  *
   5  * (c) 2013 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include "config.h"
  31
  32 #include <ctype.h>
  33 #include <limits.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36
  37 #include <mLib/macros.h>
  38 #include <mLib/mdwopt.h>
  39 #include <mLib/quis.h>
  40 #include <mLib/report.h>
  41
  42 #include "mpint.h"
  43 #include "mptext.h"
  44
  45 #include "mp-fibonacci.h"
  46
  47 /*----- Main code ---------------------------------------------------------*/
  48
  49 static void usage(FILE *fp)
  50   { pquis(fp, "Usage: $ [-r RADIX] INTEGER\n"); }
  51
  52 static void version(FILE *fp)
  53   { pquis(fp, "$, Catacomb version " VERSION "\n"); }
  54
  55 static void help(FILE *fp)
  56 {
  57   version(fp);
  58   putc('\n', fp);
  59   usage(fp);
  60   fputs("\n\
  61 Prints the Nth Fibonacci number for a given inteer N.  Input may be in\n\
  62 decimal (the default), octal with preceding zero, hex with preceding `0x',\n\
  63 or any base N between 2 and 62 inclusive with preceding `N_'.  Output\n\
  64 may be in any base between 2 and 62; the default is base 10.  For bases\n\
  65 between 11 and 36 inclusive, lowercase letters of either case are used as\n\
  66 additional digits with values 10 upwards; lowercase is always used for\n\
  67 output.  For bases between 37 and 62 inclusive, lowercase letters have\n\
  68 lower value than uppercase; hence `a' has the value 10, while `A' has the\n\
  69 value 36.\n\
  70 \n\
  71 Options provided:\n\
  72 \n\
  73 -h, --help              Display this help message.\n\
  74 -v, --version           Display the version number.\n\
  75 -u, --usage             Display a usage message.\n\
  76 \n\
  77 -r, --radix=N           Write output in base N.\n\
  78 ", fp);
  79 }
  80
  81 int main(int argc, char *argv[])
  82 {
  83   long n;
  84   int r = 10;
  85   char *p;
  86   mp *f, *lmin, *lmax, *nn;
  87   unsigned fl = 0;
  88
  89 #define f_bogus 1u
  90
  91   ego(argv[0]);
  92
  93   for (;;) {
  94     static const struct option opt[] = {
  95       { "help",         0,              0,      'h' },
  96       { "version",      0,              0,      'v' },
  97       { "usage",        0,              0,      'u' },
  98       { "radix",        OPTF_ARGREQ,    0,      'r' },
  99       { 0,              0,              0,      0 }
 100     };
 101     int i = mdwopt(argc, argv, "hvur:", opt, 0, 0, 0);
 102     if (i < 0)
 103       break;
 104     switch (i) {
 105       case 'h':
 106         help(stdout);
 107         exit(0);
 108       case 'v':
 109         version(stdout);
 110         exit(0);
 111       case 'u':
 112         usage(stdout);
 113         exit(0);
 114       case 'r':
 115         r = atoi(optarg);
 116         if (r < 2 || r > 62)
 117           die(EXIT_FAILURE, "bad radix `%s'", optarg);
 118         break;
 119       default:
 120         fl |= f_bogus;
 121         break;
 122     }
 123   }
 124
 125   if (optind + 1 != argc || (fl & f_bogus)) {
 126     usage(stderr);
 127     exit(EXIT_FAILURE);
 128   }
 129   lmin = mp_fromlong(MP_NEW, LONG_MIN);
 130   lmax = mp_fromlong(MP_NEW, LONG_MAX);
 131   p = argv[optind];
 132   while (ISSPACE(*p)) p++;
 133   nn = mp_readstring(MP_NEW, argv[optind], &p, 0);
 134   while (ISSPACE(*p)) p++;
 135   if (!nn || *p || MP_CMP(lmin, >, nn) || MP_CMP(nn, >, lmax))
 136     die(EXIT_FAILURE, "bad integer `%s'", argv[optind]);
 137   n = mp_tolong(nn);
 138   mp_drop(nn); mp_drop(lmin); mp_drop(lmax);
 139   f = mp_fibonacci(n);
 140   mp_writefile(f, stdout, r);
 141   fputc('\n', stdout);
 142   mp_drop(f);
 143   return (0);
 144 }
 145
 146 /*----- That's all, folks -------------------------------------------------*/