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 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 189 usage(void) 190 { 191 192 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n"); 193 exit(1); 194 } 195