c_cpp/etc/calc/sample_rand.c

   1 /*
   2  * sample_rand - test the libcalc random number generator
   3  *
   4  * Copyright (C) 1999-2007  Landon Curt Noll
   5  *
   6  * Calc is open software; you can redistribute it and/or modify it under
   7  * the terms of the version 2.1 of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation.
   9  *
  10  * Calc is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
  13  * Public License for more details.
  14  *
  15  * A copy of version 2.1 of the GNU Lesser General Public License is
  16  * distributed with calc under the filename COPYING-LGPL.  You should have
  17  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  * @(#) $Revision: 30.1 $
  21  * @(#) $Id: sample_rand.c,v 30.1 2007/03/16 11:09:46 chongo Exp $
  22  * @(#) $Source: /usr/local/src/bin/calc/RCS/sample_rand.c,v $
  23  *
  24  * Under source code control:   1997/04/19 22:46:49
  25  * File existed as early as:    1997
  26  *
  27  * chongo <was here> /\oo/\     http://www.isthe.com/chongo/
  28  * Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
  29  */
  30
  31 /*
  32  * usage:
  33  *      test_random [[bits] seed_string]
  34  *
  35  *      seed_string     something for which we can seed (def: default seed)
  36  *      bits            number of bits to generate
  37  */
  38
  39
  40 #include <sys/types.h>
  41 #include <stdio.h>
  42 #include "calc.h"
  43 #include "zrandom.h"
  44 #include "have_const.h"
  45 #include "lib_util.h"
  46
  47 #define DEF_CNT 128     /* default number of bits to generate */
  48
  49 extern char *program;   /* our name */
  50
  51
  52 int
  53 main(int argc, char **argv)
  54 {
  55         RANDOM *prev_state;     /* previous random number state */
  56         ZVALUE seed;            /* seed for Blum-Blum-Shub */
  57         ZVALUE random_val;      /* random number produced */
  58         long cnt;               /* number of bits to generate */
  59         char *hexstr;           /* random number as hex string */
  60
  61         /*
  62          * parse args
  63          */
  64         program = argv[0];
  65         switch (argc) {
  66         case 3:
  67                 seed = convstr2z(argv[2]);
  68                 cnt = strtol(argv[1], NULL, 0);
  69                 break;
  70         case 2:
  71                 seed = _zero_;  /* use the default seed */
  72                 cnt = strtol(argv[1], NULL, 0);
  73                 break;
  74         case 1:
  75                 seed = _zero_;  /* use the default seed */
  76                 cnt = DEF_CNT;
  77                 break;
  78         default:
  79                 fprintf(stderr, "usage: %s [[bits] seed_string]\n", program);
  80                 exit(1);
  81         }
  82         if (cnt <= 0) {
  83                 fprintf(stderr, "%s: cnt:%d must be > 0\n", program, (int)cnt);
  84                 exit(2);
  85         }
  86         printf("seed= 0x%s\n", convz2hex(seed));
  87
  88         /*
  89          * libcalc setup
  90          */
  91         libcalc_call_me_first();
  92
  93         /*
  94          * seed the generator
  95          */
  96         prev_state = zsrandom2(seed, zconst[10]);
  97         if (prev_state == NULL) {
  98                 math_error("previous random state is NULL");
  99                 /*NOTREACHED*/
 100         }
 101
 102         /*
 103          * generate random bits
 104          */
 105         zrandom(cnt, &random_val);
 106
 107         /*
 108          * convert into hex string
 109          */
 110         hexstr = convz2hex(random_val);
 111         printf("random= 0x%s\n", hexstr);
 112
 113         /*
 114          * all done
 115          */
 116         /* exit(0); */
 117         return 0;
 118 }