3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Guy Harris at Network Appliance Corp.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
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 $
38 #include <sys/types.h>
50 #include "randomize_fd.h"
52 static void usage(void);
55 main(int argc, char *argv[])
58 int ch, fd, random_exit, randomize_lines, random_type, ret,
59 selected, unique_output, unbuffer_output;
64 filename = "/dev/fd/0";
65 random_type = RANDOM_TYPE_UNSET;
66 random_exit = randomize_lines = random_type = unbuffer_output = 0;
68 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
75 if (strcmp(optarg, "-") != 0)
80 random_type = RANDOM_TYPE_LINES;
95 random_type = RANDOM_TYPE_WORDS;
108 denom = (randomize_lines ? 1 : 2);
112 denom = strtod(*argv, &ep);
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.");
128 * Act as a filter, randomly choosing lines of the standard input
129 * to write to the standard output.
132 setbuf(stdout, NULL);
135 * Act as a filter, randomizing lines read in from a given file
136 * descriptor and write the output to standard output.
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);
146 /* Compute a random exit status between 0 and denom - 1. */
148 return (int)((denom * random()) / LONG_MAX);
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
156 selected = (int)(denom * random() / LONG_MAX) == 0;
157 while ((ch = getchar()) != EOF) {
161 /* End of that line. See if we got an error. */
165 /* Now see if the next line is to be printed. */
166 selected = (int)(denom * random() / LONG_MAX) == 0;
178 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");