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 #if 0
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1994\n\
37 The Regents of the University of California. All rights reserved.\n";
38 #endif /* not lint */
39
40 #ifndef lint
41 static const char sccsid[] = "@(#)random.c 8.5 (Berkeley) 4/5/94";
42 #endif /* not lint */
43 #endif
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46
47 #include <sys/types.h>
48
49 #include <err.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <limits.h>
53 #include <locale.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <time.h>
58 #include <unistd.h>
59
60 #include "randomize_fd.h"
61
62 static void usage(void);
63
64 int
main(int argc,char * argv[])65 main(int argc, char *argv[])
66 {
67 double denom;
68 int ch, fd, random_exit, randomize_lines, random_type, ret,
69 selected, unique_output, unbuffer_output;
70 char *ep;
71 const char *filename;
72
73 denom = 0;
74 filename = "/dev/fd/0";
75 random_type = RANDOM_TYPE_UNSET;
76 random_exit = randomize_lines = unbuffer_output = 0;
77 unique_output = 1;
78
79 (void)setlocale(LC_CTYPE, "");
80
81 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
82 switch (ch) {
83 case 'e':
84 random_exit = 1;
85 break;
86 case 'f':
87 randomize_lines = 1;
88 if (strcmp(optarg, "-") != 0)
89 filename = optarg;
90 break;
91 case 'l':
92 randomize_lines = 1;
93 random_type = RANDOM_TYPE_LINES;
94 break;
95 case 'r':
96 unbuffer_output = 1;
97 break;
98 case 'u':
99 randomize_lines = 1;
100 unique_output = 1;
101 break;
102 case 'U':
103 randomize_lines = 1;
104 unique_output = 0;
105 break;
106 case 'w':
107 randomize_lines = 1;
108 random_type = RANDOM_TYPE_WORDS;
109 break;
110 default:
111 case '?':
112 usage();
113 /* NOTREACHED */
114 }
115
116 argc -= optind;
117 argv += optind;
118
119 switch (argc) {
120 case 0:
121 denom = (randomize_lines ? 1 : 2);
122 break;
123 case 1:
124 errno = 0;
125 denom = strtod(*argv, &ep);
126 if (errno == ERANGE)
127 err(1, "%s", *argv);
128 if (denom <= 0 || *ep != '\0')
129 errx(1, "denominator is not valid.");
130 if (random_exit && denom > 256)
131 errx(1, "denominator must be <= 256 for random exit.");
132 break;
133 default:
134 usage();
135 /* NOTREACHED */
136 }
137
138 srandomdev();
139
140 /*
141 * Act as a filter, randomly choosing lines of the standard input
142 * to write to the standard output.
143 */
144 if (unbuffer_output)
145 setbuf(stdout, NULL);
146
147 /*
148 * Act as a filter, randomizing lines read in from a given file
149 * descriptor and write the output to standard output.
150 */
151 if (randomize_lines) {
152 if ((fd = open(filename, O_RDONLY, 0)) < 0)
153 err(1, "%s", filename);
154 ret = randomize_fd(fd, random_type, unique_output, denom);
155 if (!random_exit)
156 return(ret);
157 }
158
159 /* Compute a random exit status between 0 and denom - 1. */
160 if (random_exit)
161 return (int)(denom * random() / RANDOM_MAX_PLUS1);
162
163 /*
164 * Select whether to print the first line. (Prime the pump.)
165 * We find a random number between 0 and denom - 1 and, if it's
166 * 0 (which has a 1 / denom chance of being true), we select the
167 * line.
168 */
169 selected = (int)(denom * random() / RANDOM_MAX_PLUS1) == 0;
170 while ((ch = getchar()) != EOF) {
171 if (selected)
172 (void)putchar(ch);
173 if (ch == '\n') {
174 /* End of that line. See if we got an error. */
175 if (ferror(stdout))
176 err(2, "stdout");
177
178 /* Now see if the next line is to be printed. */
179 selected = (int)(denom * random() /
180 RANDOM_MAX_PLUS1) == 0;
181 }
182 }
183 if (ferror(stdin))
184 err(2, "stdin");
185 exit (0);
186 }
187
188 static void
usage(void)189 usage(void)
190 {
191
192 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
193 exit(1);
194 }
195