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 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 174 usage(void) 175 { 176 177 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n"); 178 exit(1); 179 } 180