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. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#) Copyright (c) 1994 The Regents of the University of California. All rights reserved.
37 * @(#)random.c 8.5 (Berkeley) 4/5/94
38 * $FreeBSD: src/games/random/random.c,v 1.17 2005/02/09 18:22:15 ru Exp $
39 * $DragonFly: src/games/random/random.c,v 1.4 2005/03/02 06:59:23 cpressey Exp $
42 #include <sys/types.h>
54 #include "randomize_fd.h"
56 static void usage(void);
59 main(int argc, char *argv[])
62 int ch, fd, random_exit, randomize_lines, random_type, ret,
63 selected, unique_output, unbuffer_output;
68 filename = "/dev/fd/0";
69 random_type = RANDOM_TYPE_UNSET;
70 random_exit = randomize_lines = random_type = unbuffer_output = 0;
72 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
79 if (strcmp(optarg, "-") != 0)
84 random_type = RANDOM_TYPE_LINES;
99 random_type = RANDOM_TYPE_WORDS;
112 denom = (randomize_lines ? 1 : 2);
116 denom = strtod(*argv, &ep);
119 if (denom <= 0 || *ep != '\0')
120 errx(1, "denominator is not valid.");
121 if (random_exit && denom > 255)
122 errx(1, "denominator must be <= 255 for random exit.");
132 * Act as a filter, randomly choosing lines of the standard input
133 * to write to the standard output.
136 setbuf(stdout, NULL);
139 * Act as a filter, randomizing lines read in from a given file
140 * descriptor and write the output to standard output.
142 if (randomize_lines) {
143 if ((fd = open(filename, O_RDONLY, 0)) < 0)
144 err(1, "%s", filename);
145 ret = randomize_fd(fd, random_type, unique_output, denom);
150 /* Compute a random exit status between 0 and denom - 1. */
152 return (int)((denom * random()) / LONG_MAX);
155 * Select whether to print the first line. (Prime the pump.)
156 * We find a random number between 0 and denom - 1 and, if it's
157 * 0 (which has a 1 / denom chance of being true), we select the
160 selected = (int)(denom * random() / LONG_MAX) == 0;
161 while ((ch = getchar()) != EOF) {
165 /* End of that line. See if we got an error. */
169 /* Now see if the next line is to be printed. */
170 selected = (int)(denom * random() / LONG_MAX) == 0;
182 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");