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
50 static void usage(void) __dead2;
51
52 int
main(int argc,char * argv[])53 main(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
175 static void
usage(void)176 usage(void)
177 {
178
179 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
180 exit(1);
181 }
182