1 /*- 2 * Copyright (C) 2003 Sean Chittenden <seanc@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/games/random/randomize_fd.c,v 1.2.2.1 2003/02/15 10:34:35 seanc Exp $ 27 * $DragonFly: src/games/random/randomize_fd.c,v 1.2 2003/06/17 04:25:24 dillon Exp $ 28 */ 29 30 #include <sys/types.h> 31 #include <sys/param.h> 32 33 #include <ctype.h> 34 #include <err.h> 35 #include <stdlib.h> 36 #include <stdio.h> 37 #include <string.h> 38 #include <unistd.h> 39 40 #include "randomize_fd.h" 41 42 static struct rand_node *rand_root; 43 static struct rand_node *rand_tail; 44 45 static struct rand_node * 46 rand_node_allocate(void) 47 { 48 struct rand_node *n; 49 50 n = (struct rand_node *)malloc(sizeof(struct rand_node)); 51 if (n == NULL) 52 err(1, "malloc"); 53 54 n->len = 0; 55 n->cp = NULL; 56 n->next = NULL; 57 return(n); 58 } 59 60 static void 61 rand_node_free(struct rand_node *n) 62 { 63 if (n != NULL) { 64 if (n->cp != NULL) 65 free(n->cp); 66 67 free(n); 68 } 69 } 70 71 static void 72 rand_node_free_rec(struct rand_node *n) 73 { 74 if (n != NULL) { 75 if (n->next != NULL) 76 rand_node_free_rec(n->next); 77 78 rand_node_free(n); 79 } 80 } 81 82 static void 83 rand_node_append(struct rand_node *n) 84 { 85 if (rand_root == NULL) 86 rand_root = rand_tail = n; 87 else { 88 rand_tail->next = n; 89 rand_tail = n; 90 } 91 } 92 93 int 94 randomize_fd(int fd, int type, int unique, double denom) 95 { 96 u_char *buf, *p; 97 u_int numnode, j, selected, slen; 98 struct rand_node *n, *prev; 99 int bufleft, eof, fndstr, ret; 100 size_t bufc, buflen, i; 101 ssize_t len; 102 103 rand_root = rand_tail = NULL; 104 bufc = i = 0; 105 bufleft = eof = fndstr = numnode = ret = 0; 106 107 if (type == RANDOM_TYPE_UNSET) 108 type = RANDOM_TYPE_LINES; 109 110 buflen = sizeof(u_char) * MAXBSIZE; 111 buf = (u_char *)malloc(buflen); 112 if (buf == NULL) 113 err(1, "malloc"); 114 115 while (!eof) { 116 /* Check to see if we have bits in the buffer */ 117 if (bufleft == 0) { 118 len = read(fd, buf, buflen); 119 if (len == -1) 120 err(1, "read"); 121 else if (len == 0) { 122 eof++; 123 break; 124 } else if ((size_t)len < buflen) 125 buflen = (size_t)len; 126 127 bufleft = (int)len; 128 } 129 130 /* Look for a newline */ 131 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) { 132 if (i == buflen) { 133 if (fndstr) { 134 if (!eof) { 135 memmove(buf, &buf[bufc], i - bufc); 136 i -= bufc; 137 bufc = 0; 138 len = read(fd, &buf[i], buflen - i); 139 if (len == -1) 140 err(1, "read"); 141 else if (len == 0) { 142 eof++; 143 break; 144 } else if (len < (ssize_t)(buflen - i)) 145 buflen = i + (size_t)len; 146 147 bufleft = (int)len; 148 fndstr = 0; 149 } 150 } else { 151 p = (u_char *)realloc(buf, buflen * 2); 152 if (p == NULL) 153 err(1, "realloc"); 154 155 buf = p; 156 if (!eof) { 157 len = read(fd, &buf[i], buflen); 158 if (len == -1) 159 err(1, "read"); 160 else if (len == 0) { 161 eof++; 162 break; 163 } else if (len < (ssize_t)(buflen - i)) 164 buflen = (size_t)len; 165 166 bufleft = (int)len; 167 } 168 169 buflen *= 2; 170 } 171 } 172 173 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') || 174 (type == RANDOM_TYPE_WORDS && isspace((int)buf[i])) || 175 (eof && i == buflen - 1)) { 176 make_token: 177 n = rand_node_allocate(); 178 if (-1 != (int)i) { 179 slen = i - (u_long)bufc; 180 n->len = slen + 2; 181 n->cp = (u_char *)malloc(slen + 2); 182 if (n->cp == NULL) 183 err(1, "malloc"); 184 185 memmove(n->cp, &buf[bufc], slen); 186 n->cp[slen] = buf[i]; 187 n->cp[slen + 1] = '\0'; 188 bufc = i + 1; 189 } 190 rand_node_append(n); 191 fndstr = 1; 192 numnode++; 193 } 194 } 195 } 196 197 (void)close(fd); 198 199 /* Necessary evil to compensate for files that don't end with a newline */ 200 if (bufc != i) { 201 i--; 202 goto make_token; 203 } 204 205 for (i = numnode; i > 0; i--) { 206 selected = ((int)denom * random())/(((double)RAND_MAX + 1) / numnode); 207 208 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) { 209 if (j == selected) { 210 if (n->cp == NULL) 211 break; 212 213 ret = printf("%.*s", (int)n->len - 1, n->cp); 214 if (ret < 0) 215 err(1, "printf"); 216 if (unique) { 217 if (n == rand_root) 218 rand_root = n->next; 219 if (n == rand_tail) 220 rand_tail = prev; 221 222 prev->next = n->next; 223 rand_node_free(n); 224 numnode--; 225 break; 226 } 227 } 228 } 229 } 230 231 fflush(stdout); 232 233 if (!unique) 234 rand_node_free_rec(rand_root); 235 236 return(0); 237 } 238