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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#) Copyright (c) 1994 The Regents of the University of California. All rights reserved. 37 * @(#)random.c 8.5 (Berkeley) 4/5/94 38 * $FreeBSD: src/games/random/random.c,v 1.17 2005/02/09 18:22:15 ru Exp $ 39 * $DragonFly: src/games/random/random.c,v 1.4 2005/03/02 06:59:23 cpressey Exp $ 40 */ 41 42 #include <sys/types.h> 43 44 #include <err.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <limits.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <time.h> 52 #include <unistd.h> 53 54 #include "randomize_fd.h" 55 56 static void usage(void); 57 58 int 59 main(int argc, char *argv[]) 60 { 61 double denom; 62 int ch, fd, random_exit, randomize_lines, random_type, ret, 63 selected, unique_output, unbuffer_output; 64 char *ep; 65 const char *filename; 66 67 denom = 0; 68 filename = "/dev/fd/0"; 69 random_type = RANDOM_TYPE_UNSET; 70 random_exit = randomize_lines = random_type = unbuffer_output = 0; 71 unique_output = 1; 72 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1) 73 switch (ch) { 74 case 'e': 75 random_exit = 1; 76 break; 77 case 'f': 78 randomize_lines = 1; 79 if (strcmp(optarg, "-") != 0) 80 filename = optarg; 81 break; 82 case 'l': 83 randomize_lines = 1; 84 random_type = RANDOM_TYPE_LINES; 85 break; 86 case 'r': 87 unbuffer_output = 1; 88 break; 89 case 'u': 90 randomize_lines = 1; 91 unique_output = 1; 92 break; 93 case 'U': 94 randomize_lines = 1; 95 unique_output = 0; 96 break; 97 case 'w': 98 randomize_lines = 1; 99 random_type = RANDOM_TYPE_WORDS; 100 break; 101 default: 102 case '?': 103 usage(); 104 /* NOTREACHED */ 105 } 106 107 argc -= optind; 108 argv += optind; 109 110 switch (argc) { 111 case 0: 112 denom = (randomize_lines ? 1 : 2); 113 break; 114 case 1: 115 errno = 0; 116 denom = strtod(*argv, &ep); 117 if (errno == ERANGE) 118 err(1, "%s", *argv); 119 if (denom <= 0 || *ep != '\0') 120 errx(1, "denominator is not valid."); 121 if (random_exit && denom > 255) 122 errx(1, "denominator must be <= 255 for random exit."); 123 break; 124 default: 125 usage(); 126 /* NOTREACHED */ 127 } 128 129 srandomdev(); 130 131 /* 132 * Act as a filter, randomly choosing lines of the standard input 133 * to write to the standard output. 134 */ 135 if (unbuffer_output) 136 setbuf(stdout, NULL); 137 138 /* 139 * Act as a filter, randomizing lines read in from a given file 140 * descriptor and write the output to standard output. 141 */ 142 if (randomize_lines) { 143 if ((fd = open(filename, O_RDONLY, 0)) < 0) 144 err(1, "%s", filename); 145 ret = randomize_fd(fd, random_type, unique_output, denom); 146 if (!random_exit) 147 return(ret); 148 } 149 150 /* Compute a random exit status between 0 and denom - 1. */ 151 if (random_exit) 152 return (int)((denom * random()) / LONG_MAX); 153 154 /* 155 * Select whether to print the first line. (Prime the pump.) 156 * We find a random number between 0 and denom - 1 and, if it's 157 * 0 (which has a 1 / denom chance of being true), we select the 158 * line. 159 */ 160 selected = (int)(denom * random() / LONG_MAX) == 0; 161 while ((ch = getchar()) != EOF) { 162 if (selected) 163 (void)putchar(ch); 164 if (ch == '\n') { 165 /* End of that line. See if we got an error. */ 166 if (ferror(stdout)) 167 err(2, "stdout"); 168 169 /* Now see if the next line is to be printed. */ 170 selected = (int)(denom * random() / LONG_MAX) == 0; 171 } 172 } 173 if (ferror(stdin)) 174 err(2, "stdin"); 175 exit (0); 176 } 177 178 static void 179 usage(void) 180 { 181 182 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n"); 183 exit(1); 184 } 185