games/random/random.c

   1 /*-
   2  * Copyright (c) 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Guy Harris at Network Appliance Corp.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#) Copyright (c) 1994 The Regents of the University of California.  All rights reserved.
  33  * @(#)random.c 8.5 (Berkeley) 4/5/94
  34  * $FreeBSD: src/games/random/random.c,v 1.17 2005/02/09 18:22:15 ru Exp $
  35  * $DragonFly: src/games/random/random.c,v 1.4 2005/03/02 06:59:23 cpressey Exp $
  36  */
  37
  38 #include <sys/types.h>
  39
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <limits.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <time.h>
  48 #include <unistd.h>
  49
  50 #include "randomize_fd.h"
  51
  52 static void usage(void);
  53
  54 int
  55 main(int argc, char *argv[])
  56 {
  57         double denom;
  58         int ch, fd, random_exit, randomize_lines, random_type, ret,
  59                 selected, unique_output, unbuffer_output;
  60         char *ep;
  61         const char *filename;
  62
  63         denom = 0;
  64         filename = "/dev/fd/0";
  65         random_type = RANDOM_TYPE_UNSET;
  66         random_exit = randomize_lines = random_type = unbuffer_output = 0;
  67         unique_output = 1;
  68         while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
  69                 switch (ch) {
  70                 case 'e':
  71                         random_exit = 1;
  72                         break;
  73                 case 'f':
  74                         randomize_lines = 1;
  75                         if (strcmp(optarg, "-") != 0)
  76                                 filename = optarg;
  77                         break;
  78                 case 'l':
  79                         randomize_lines = 1;
  80                         random_type = RANDOM_TYPE_LINES;
  81                         break;
  82                 case 'r':
  83                         unbuffer_output = 1;
  84                         break;
  85                 case 'u':
  86                         randomize_lines = 1;
  87                         unique_output = 1;
  88                         break;
  89                 case 'U':
  90                         randomize_lines = 1;
  91                         unique_output = 0;
  92                         break;
  93                 case 'w':
  94                         randomize_lines = 1;
  95                         random_type = RANDOM_TYPE_WORDS;
  96                         break;
  97                 default:
  98                 case '?':
  99                         usage();
 100                         /* NOTREACHED */
 101                 }
 102
 103         argc -= optind;
 104         argv += optind;
 105
 106         switch (argc) {
 107         case 0:
 108                 denom = (randomize_lines ? 1 : 2);
 109                 break;
 110         case 1:
 111                 errno = 0;
 112                 denom = strtod(*argv, &ep);
 113                 if (errno == ERANGE)
 114                         err(1, "%s", *argv);
 115                 if (denom <= 0 || *ep != '\0')
 116                         errx(1, "denominator is not valid.");
 117                 if (random_exit && denom > 255)
 118                         errx(1, "denominator must be <= 255 for random exit.");
 119                 break;
 120         default:
 121                 usage();
 122                 /* NOTREACHED */
 123         }
 124
 125         srandomdev();
 126
 127         /*
 128          * Act as a filter, randomly choosing lines of the standard input
 129          * to write to the standard output.
 130          */
 131         if (unbuffer_output)
 132                 setbuf(stdout, NULL);
 133
 134         /*
 135          * Act as a filter, randomizing lines read in from a given file
 136          * descriptor and write the output to standard output.
 137          */
 138         if (randomize_lines) {
 139                 if ((fd = open(filename, O_RDONLY, 0)) < 0)
 140                         err(1, "%s", filename);
 141                 ret = randomize_fd(fd, random_type, unique_output, denom);
 142                 if (!random_exit)
 143                         return(ret);
 144         }
 145
 146         /* Compute a random exit status between 0 and denom - 1. */
 147         if (random_exit)
 148                 return (int)((denom * random()) / LONG_MAX);
 149
 150         /*
 151          * Select whether to print the first line.  (Prime the pump.)
 152          * We find a random number between 0 and denom - 1 and, if it's
 153          * 0 (which has a 1 / denom chance of being true), we select the
 154          * line.
 155          */
 156         selected = (int)(denom * random() / LONG_MAX) == 0;
 157         while ((ch = getchar()) != EOF) {
 158                 if (selected)
 159                         (void)putchar(ch);
 160                 if (ch == '\n') {
 161                         /* End of that line.  See if we got an error. */
 162                         if (ferror(stdout))
 163                                 err(2, "stdout");
 164
 165                         /* Now see if the next line is to be printed. */
 166                         selected = (int)(denom * random() / LONG_MAX) == 0;
 167                 }
 168         }
 169         if (ferror(stdin))
 170                 err(2, "stdin");
 171         exit (0);
 172 }
 173
 174 static void
 175 usage(void)
 176 {
 177
 178         fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
 179         exit(1);
 180 }