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
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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
39 static const char copyright[] =
40 "@(#) Copyright (c) 1994\n\
41 The Regents of the University of California. All rights reserved.\n";
45 static const char sccsid[] = "@(#)random.c 8.5 (Berkeley) 4/5/94";
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
51 #include <sys/types.h>
63 #include "randomize_fd.h"
66 * The random() function is defined to return values between 0 and
67 * 2^31 - 1 inclusive in random(3).
69 #define RANDOM_MAX 0x7fffffffL
71 static void usage(void);
74 main(int argc, char *argv[])
77 int ch, fd, random_exit, randomize_lines, random_type, ret,
78 selected, unique_output, unbuffer_output;
83 filename = "/dev/fd/0";
84 random_type = RANDOM_TYPE_UNSET;
85 random_exit = randomize_lines = random_type = unbuffer_output = 0;
87 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
94 if (strcmp(optarg, "-") != 0)
99 random_type = RANDOM_TYPE_LINES;
114 random_type = RANDOM_TYPE_WORDS;
127 denom = (randomize_lines ? 1 : 2);
131 denom = strtod(*argv, &ep);
134 if (denom <= 0 || *ep != '\0')
135 errx(1, "denominator is not valid.");
136 if (random_exit && denom > 255)
137 errx(1, "denominator must be <= 255 for random exit.");
147 * Act as a filter, randomly choosing lines of the standard input
148 * to write to the standard output.
151 setbuf(stdout, NULL);
154 * Act as a filter, randomizing lines read in from a given file
155 * descriptor and write the output to standard output.
157 if (randomize_lines) {
158 if ((fd = open(filename, O_RDONLY, 0)) < 0)
159 err(1, "%s", filename);
160 ret = randomize_fd(fd, random_type, unique_output, denom);
165 /* Compute a random exit status between 0 and denom - 1. */
167 return (int)((denom * random()) / RANDOM_MAX);
170 * Select whether to print the first line. (Prime the pump.)
171 * We find a random number between 0 and denom - 1 and, if it's
172 * 0 (which has a 1 / denom chance of being true), we select the
175 selected = (int)(denom * random() / RANDOM_MAX) == 0;
176 while ((ch = getchar()) != EOF) {
180 /* End of that line. See if we got an error. */
184 /* Now see if the next line is to be printed. */
185 selected = (int)(denom * random() / RANDOM_MAX) == 0;
197 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");