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
33#include <sys/types.h>
34
35#include <err.h>
36#include <errno.h>
37#include <fcntl.h>
38#include <limits.h>
39#include <locale.h>
40#include <stdbool.h>
41#include <stdint.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <time.h>
46#include <unistd.h>
47
48#include "randomize_fd.h"
49
50static void usage(void) __dead2;
51
52int
53main(int argc, char *argv[])
54{
55	double denom;
56	int ch, fd, random_exit, randomize_lines, random_type, ret,
57	    unique_output, unbuffer_output;
58	bool selected;
59	char *ep;
60	const char *filename;
61
62	denom = 0.;
63	filename = "/dev/fd/0";
64	random_type = RANDOM_TYPE_UNSET;
65	random_exit = randomize_lines = unbuffer_output = 0;
66	unique_output = 1;
67
68	(void)setlocale(LC_CTYPE, "");
69
70	while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
71		switch (ch) {
72		case 'e':
73			random_exit = 1;
74			break;
75		case 'f':
76			randomize_lines = 1;
77			if (strcmp(optarg, "-") != 0)
78				filename = optarg;
79			break;
80		case 'l':
81			randomize_lines = 1;
82			random_type = RANDOM_TYPE_LINES;
83			break;
84		case 'r':
85			unbuffer_output = 1;
86			break;
87		case 'u':
88			randomize_lines = 1;
89			unique_output = 1;
90			break;
91		case 'U':
92			randomize_lines = 1;
93			unique_output = 0;
94			break;
95		case 'w':
96			randomize_lines = 1;
97			random_type = RANDOM_TYPE_WORDS;
98			break;
99		default:
100		case '?':
101			usage();
102			/* NOTREACHED */
103		}
104
105	argc -= optind;
106	argv += optind;
107
108	switch (argc) {
109	case 0:
110		denom = (randomize_lines ? 1. : 2.);
111		break;
112	case 1:
113		errno = 0;
114		denom = strtod(*argv, &ep);
115		if (errno == ERANGE)
116			err(1, "%s", *argv);
117		if (denom < 1. || *ep != '\0')
118			errx(1, "denominator is not valid.");
119		if (random_exit && denom > 256.)
120			errx(1, "denominator must be <= 256 for random exit.");
121		break;
122	default:
123		usage();
124		/* NOTREACHED */
125	}
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 (arc4random_uniform(denom));
149
150	/*
151	 * Filter stdin, selecting lines with probability 1/denom, one
152	 * character at a time.
153	 */
154	do {
155		selected = random_uniform_denom(denom);
156		if (selected) {
157			while ((ch = getchar()) != EOF) {
158				putchar(ch);
159				if (ch == '\n')
160					break;
161			}
162		} else {
163			while ((ch = getchar()) != EOF)
164				if (ch == '\n')
165					break;
166		}
167		if (ferror(stdout))
168			err(2, "stdout");
169	} while (ch != EOF);
170	if (ferror(stdin))
171		err(2, "stdin");
172	exit (0);
173}
174
175static void
176usage(void)
177{
178
179	fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
180	exit(1);
181}
182