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

   1 /* -*-c-*-
   2  *
   3  * Example factorial computation
   4  *
   5  * (c) 2000 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 "mpmul.h"
  44 #include "mptext.h"
  45
  46 /*----- Main code ---------------------------------------------------------*/
  47
  48 static void usage(FILE *fp)
  49 {
  50   pquis(fp, "Usage: $ [-r RADIX] INTEGER\n");
  51 }
  52
  53 static void version(FILE *fp)
  54 {
  55   pquis(fp, "$, Catacomb version " VERSION "\n");
  56 }
  57
  58 static void help(FILE *fp)
  59 {
  60   version(fp);
  61   putc('\n', fp);
  62   usage(fp);
  63   fputs("\n\
  64 Prints the factorial of the given integer on its output.  Input may be\n\
  65 in decimal (the default), octal with preceding zero, hex with preceding\n\
  66 `0x', or any base N between 2 and 62 inclusive with preceding `N_'.\n\
  67 Output may be in any base between 2 and 62; the default is base 10.  For\n\
  68 bases between 11 and 36 inclusive, lowercase letters of either case are\n\
  69 used as additional digits with values 10 upwards; lowercase is always\n\
  70 used for output.  For bases between 37 and 62 inclusive, lowercase letters\n\
  71 have lower value than uppercase; hence `a' has the value 10, while `A' has\n\
  72 the value 36.\n\
  73 \n\
  74 Options provided:\n\
  75 \n\
  76 -h, --help              Display this help message.\n\
  77 -v, --version           Display the version number.\n\
  78 -u, --usage             Display a usage message.\n\
  79 \n\
  80 -r, --radix=N           Write output in base N.\n\
  81 ", fp);
  82 }
  83
  84 int main(int argc, char *argv[])
  85 {
  86   unsigned long x;
  87   int r = 10;
  88   char *p;
  89   mp *f, *ulmax, *xx;
  90   unsigned fl = 0;
  91
  92 #define f_bogus 1u
  93
  94   ego(argv[0]);
  95
  96   for (;;) {
  97     static const struct option opt[] = {
  98       { "help",         0,              0,      'h' },
  99       { "version",      0,              0,      'v' },
 100       { "usage",        0,              0,      'u' },
 101       { "radix",        OPTF_ARGREQ,    0,      'r' },
 102       { 0,              0,              0,      0 }
 103     };
 104     int i = mdwopt(argc, argv, "hvur:", opt, 0, 0, 0);
 105     if (i < 0)
 106       break;
 107     switch (i) {
 108       case 'h':
 109         help(stdout);
 110         exit(0);
 111       case 'v':
 112         version(stdout);
 113         exit(0);
 114       case 'u':
 115         usage(stdout);
 116         exit(0);
 117       case 'r':
 118         r = atoi(optarg);
 119         if (r < 2 || r > 62)
 120           die(EXIT_FAILURE, "bad radix `%s'", optarg);
 121         break;
 122       default:
 123         fl |= f_bogus;
 124         break;
 125     }
 126   }
 127
 128   if (optind + 1 != argc || (fl & f_bogus)) {
 129     usage(stderr);
 130     exit(EXIT_FAILURE);
 131   }
 132   ulmax = mp_fromulong(MP_NEW, ULONG_MAX);
 133   p = argv[optind];
 134   while (ISSPACE(*p))
 135     p++;
 136   xx = mp_readstring(MP_NEW, argv[optind], &p, 0);
 137   while (ISSPACE(*p))
 138     p++;
 139   if (!xx || *p || MP_CMP(xx, <, MP_ZERO) || MP_CMP(xx, >, ulmax))
 140     die(EXIT_FAILURE, "bad integer `%s'", argv[optind]);
 141   x = mp_toulong(xx);
 142   mp_drop(xx);
 143   mp_drop(ulmax);
 144   f = mp_factorial(x);
 145   mp_writefile(f, stdout, r);
 146   fputc('\n', stdout);
 147   mp_drop(f);
 148   return (0);
 149 }
 150
 151 /*----- That's all, folks -------------------------------------------------*/