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 * $DragonFly: src/games/random/random.c,v 1.4 2005/03/02 06:59:23 cpressey Exp $ 36 */ 37 38 #include <sys/types.h> 39 40 #include <err.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <limits.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <time.h> 48 #include <unistd.h> 49 50 #include "randomize_fd.h" 51 52 static void usage(void); 53 54 int 55 main(int argc, char *argv[]) 56 { 57 double denom; 58 int ch, fd, random_exit, randomize_lines, random_type, ret, 59 selected, unique_output, unbuffer_output; 60 char *ep; 61 const char *filename; 62 63 denom = 0; 64 filename = "/dev/fd/0"; 65 random_type = RANDOM_TYPE_UNSET; 66 random_exit = randomize_lines = random_type = unbuffer_output = 0; 67 unique_output = 1; 68 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1) 69 switch (ch) { 70 case 'e': 71 random_exit = 1; 72 break; 73 case 'f': 74 randomize_lines = 1; 75 if (strcmp(optarg, "-") != 0) 76 filename = optarg; 77 break; 78 case 'l': 79 randomize_lines = 1; 80 random_type = RANDOM_TYPE_LINES; 81 break; 82 case 'r': 83 unbuffer_output = 1; 84 break; 85 case 'u': 86 randomize_lines = 1; 87 unique_output = 1; 88 break; 89 case 'U': 90 randomize_lines = 1; 91 unique_output = 0; 92 break; 93 case 'w': 94 randomize_lines = 1; 95 random_type = RANDOM_TYPE_WORDS; 96 break; 97 default: 98 case '?': 99 usage(); 100 /* NOTREACHED */ 101 } 102 103 argc -= optind; 104 argv += optind; 105 106 switch (argc) { 107 case 0: 108 denom = (randomize_lines ? 1 : 2); 109 break; 110 case 1: 111 errno = 0; 112 denom = strtod(*argv, &ep); 113 if (errno == ERANGE) 114 err(1, "%s", *argv); 115 if (denom <= 0 || *ep != '\0') 116 errx(1, "denominator is not valid."); 117 if (random_exit && denom > 255) 118 errx(1, "denominator must be <= 255 for random exit."); 119 break; 120 default: 121 usage(); 122 /* NOTREACHED */ 123 } 124 125 srandomdev(); 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 (int)((denom * random()) / LONG_MAX); 149 150 /* 151 * Select whether to print the first line. (Prime the pump.) 152 * We find a random number between 0 and denom - 1 and, if it's 153 * 0 (which has a 1 / denom chance of being true), we select the 154 * line. 155 */ 156 selected = (int)(denom * random() / LONG_MAX) == 0; 157 while ((ch = getchar()) != EOF) { 158 if (selected) 159 (void)putchar(ch); 160 if (ch == '\n') { 161 /* End of that line. See if we got an error. */ 162 if (ferror(stdout)) 163 err(2, "stdout"); 164 165 /* Now see if the next line is to be printed. */ 166 selected = (int)(denom * random() / LONG_MAX) == 0; 167 } 168 } 169 if (ferror(stdin)) 170 err(2, "stdin"); 171 exit (0); 172 } 173 174 static void 175 usage(void) 176 { 177 178 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n"); 179 exit(1); 180 } 181