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 #include <sys/types.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <limits.h> 39 #include <locale.h> 40 #include <stdbool.h> 41 #include <stdint.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <time.h> 46 #include <unistd.h> 47 48 #include "randomize_fd.h" 49 50 static void usage(void) __dead2; 51 52 int 53 main(int argc, char *argv[]) 54 { 55 double denom; 56 int ch, fd, random_exit, randomize_lines, random_type, ret, 57 unique_output, unbuffer_output; 58 bool selected; 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 = unbuffer_output = 0; 66 unique_output = 1; 67 68 (void)setlocale(LC_CTYPE, ""); 69 70 while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1) 71 switch (ch) { 72 case 'e': 73 random_exit = 1; 74 break; 75 case 'f': 76 randomize_lines = 1; 77 if (strcmp(optarg, "-") != 0) 78 filename = optarg; 79 break; 80 case 'l': 81 randomize_lines = 1; 82 random_type = RANDOM_TYPE_LINES; 83 break; 84 case 'r': 85 unbuffer_output = 1; 86 break; 87 case 'u': 88 randomize_lines = 1; 89 unique_output = 1; 90 break; 91 case 'U': 92 randomize_lines = 1; 93 unique_output = 0; 94 break; 95 case 'w': 96 randomize_lines = 1; 97 random_type = RANDOM_TYPE_WORDS; 98 break; 99 default: 100 case '?': 101 usage(); 102 /* NOTREACHED */ 103 } 104 105 argc -= optind; 106 argv += optind; 107 108 switch (argc) { 109 case 0: 110 denom = (randomize_lines ? 1. : 2.); 111 break; 112 case 1: 113 errno = 0; 114 denom = strtod(*argv, &ep); 115 if (errno == ERANGE) 116 err(1, "%s", *argv); 117 if (denom < 1. || *ep != '\0') 118 errx(1, "denominator is not valid."); 119 if (random_exit && denom > 256.) 120 errx(1, "denominator must be <= 256 for random exit."); 121 break; 122 default: 123 usage(); 124 /* NOTREACHED */ 125 } 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 (arc4random_uniform(denom)); 149 150 /* 151 * Filter stdin, selecting lines with probability 1/denom, one 152 * character at a time. 153 */ 154 do { 155 selected = random_uniform_denom(denom); 156 if (selected) { 157 while ((ch = getchar()) != EOF) { 158 putchar(ch); 159 if (ch == '\n') 160 break; 161 } 162 } else { 163 while ((ch = getchar()) != EOF) 164 if (ch == '\n') 165 break; 166 } 167 if (ferror(stdout)) 168 err(2, "stdout"); 169 } while (ch != EOF); 170 if (ferror(stdin)) 171 err(2, "stdin"); 172 exit (0); 173 } 174 175 static void 176 usage(void) 177 { 178 179 fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n"); 180 exit(1); 181 } 182