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 * @(#) Copyright (c) 1994 The Regents of the University of California. All rights reserved.
33 * @(#)random.c 8.5 (Berkeley) 4/5/94
34 * $FreeBSD: src/games/random/random.c,v 1.17 2005/02/09 18:22:15 ru Exp $
35 */
36
37 #include <sys/types.h>
38
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <limits.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <time.h>
47 #include <unistd.h>
48
49 #include "randomize_fd.h"
50
51 static void usage(void);
52
53 int
main(int argc,char * argv[])54 main(int argc, char *argv[])
55 {
56 double denom;
57 int ch, fd, random_exit, randomize_lines, random_type, ret,
58 selected, unique_output, unbuffer_output;
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 = random_type = unbuffer_output = 0;
66 unique_output = 1;
67 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
68 switch (ch) {
69 case 'e':
70 random_exit = 1;
71 break;
72 case 'f':
73 randomize_lines = 1;
74 if (strcmp(optarg, "-") != 0)
75 filename = optarg;
76 break;
77 case 'l':
78 randomize_lines = 1;
79 random_type = RANDOM_TYPE_LINES;
80 break;
81 case 'r':
82 unbuffer_output = 1;
83 break;
84 case 'u':
85 randomize_lines = 1;
86 unique_output = 1;
87 break;
88 case 'U':
89 randomize_lines = 1;
90 unique_output = 0;
91 break;
92 case 'w':
93 randomize_lines = 1;
94 random_type = RANDOM_TYPE_WORDS;
95 break;
96 default:
97 case '?':
98 usage();
99 /* NOTREACHED */
100 }
101
102 argc -= optind;
103 argv += optind;
104
105 switch (argc) {
106 case 0:
107 denom = (randomize_lines ? 1 : 2);
108 break;
109 case 1:
110 errno = 0;
111 denom = strtod(*argv, &ep);
112 if (errno == ERANGE)
113 err(1, "%s", *argv);
114 if (denom <= 0 || *ep != '\0')
115 errx(1, "denominator is not valid.");
116 if (random_exit && denom > 255)
117 errx(1, "denominator must be <= 255 for random exit.");
118 break;
119 default:
120 usage();
121 /* NOTREACHED */
122 }
123
124 srandomdev();
125
126 /*
127 * Act as a filter, randomly choosing lines of the standard input
128 * to write to the standard output.
129 */
130 if (unbuffer_output)
131 setbuf(stdout, NULL);
132
133 /*
134 * Act as a filter, randomizing lines read in from a given file
135 * descriptor and write the output to standard output.
136 */
137 if (randomize_lines) {
138 if ((fd = open(filename, O_RDONLY, 0)) < 0)
139 err(1, "%s", filename);
140 ret = randomize_fd(fd, random_type, unique_output, denom);
141 if (!random_exit)
142 return(ret);
143 }
144
145 /* Compute a random exit status between 0 and denom - 1. */
146 if (random_exit)
147 return (int)((denom * random()) / LONG_MAX);
148
149 /*
150 * Select whether to print the first line. (Prime the pump.)
151 * We find a random number between 0 and denom - 1 and, if it's
152 * 0 (which has a 1 / denom chance of being true), we select the
153 * line.
154 */
155 selected = (int)(denom * random() / LONG_MAX) == 0;
156 while ((ch = getchar()) != EOF) {
157 if (selected)
158 putchar(ch);
159 if (ch == '\n') {
160 /* End of that line. See if we got an error. */
161 if (ferror(stdout))
162 err(2, "stdout");
163
164 /* Now see if the next line is to be printed. */
165 selected = (int)(denom * random() / LONG_MAX) == 0;
166 }
167 }
168 if (ferror(stdin))
169 err(2, "stdin");
170 exit (0);
171 }
172
173 static void
usage(void)174 usage(void)
175 {
176
177 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
178 exit(1);
179 }
180