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 */ 28 29 #include <sys/types.h> 30 #include <sys/param.h> 31 32 #include <ctype.h> 33 #include <err.h> 34 #include <stdlib.h> 35 #include <stdio.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #include "randomize_fd.h" 40 41 static struct rand_node *rand_root; 42 static struct rand_node *rand_tail; 43 44 static struct rand_node * 45 rand_node_allocate(void) 46 { 47 struct rand_node *n; 48 49 n = (struct rand_node *)malloc(sizeof(struct rand_node)); 50 if (n == NULL) 51 err(1, "malloc"); 52 53 n->len = 0; 54 n->cp = NULL; 55 n->next = NULL; 56 return(n); 57 } 58 59 static void 60 rand_node_free(struct rand_node *n) 61 { 62 if (n != NULL) { 63 if (n->cp != NULL) 64 free(n->cp); 65 66 free(n); 67 } 68 } 69 70 static void 71 rand_node_free_rec(struct rand_node *n) 72 { 73 if (n != NULL) { 74 if (n->next != NULL) 75 rand_node_free_rec(n->next); 76 77 rand_node_free(n); 78 } 79 } 80 81 static void 82 rand_node_append(struct rand_node *n) 83 { 84 if (rand_root == NULL) 85 rand_root = rand_tail = n; 86 else { 87 rand_tail->next = n; 88 rand_tail = n; 89 } 90 } 91 92 int 93 randomize_fd(int fd, int type, int unique, double denom) 94 { 95 u_char *buf, *p; 96 u_int numnode, j, selected, slen; 97 struct rand_node *n, *prev; 98 int bufleft, eof, fndstr, ret; 99 size_t bufc, buflen, i; 100 ssize_t len; 101 102 rand_root = rand_tail = NULL; 103 bufc = i = 0; 104 bufleft = eof = fndstr = numnode = ret = 0; 105 106 if (type == RANDOM_TYPE_UNSET) 107 type = RANDOM_TYPE_LINES; 108 109 buflen = sizeof(u_char) * MAXBSIZE; 110 buf = (u_char *)malloc(buflen); 111 if (buf == NULL) 112 err(1, "malloc"); 113 114 while (!eof) { 115 /* Check to see if we have bits in the buffer */ 116 if (bufleft == 0) { 117 len = read(fd, buf, buflen); 118 if (len == -1) 119 err(1, "read"); 120 else if (len == 0) { 121 eof++; 122 break; 123 } else if ((size_t)len < buflen) 124 buflen = (size_t)len; 125 126 bufleft = (int)len; 127 } 128 129 /* Look for a newline */ 130 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) { 131 if (i == buflen) { 132 if (fndstr) { 133 if (!eof) { 134 memmove(buf, &buf[bufc], i - bufc); 135 i -= bufc; 136 bufc = 0; 137 len = read(fd, &buf[i], buflen - i); 138 if (len == -1) 139 err(1, "read"); 140 else if (len == 0) { 141 eof++; 142 break; 143 } else if (len < (ssize_t)(buflen - i)) 144 buflen = i + (size_t)len; 145 146 bufleft = (int)len; 147 fndstr = 0; 148 } 149 } else { 150 p = (u_char *)realloc(buf, buflen * 2); 151 if (p == NULL) 152 err(1, "realloc"); 153 154 buf = p; 155 if (!eof) { 156 len = read(fd, &buf[i], buflen); 157 if (len == -1) 158 err(1, "read"); 159 else if (len == 0) { 160 eof++; 161 break; 162 } else if (len < (ssize_t)(buflen - i)) 163 buflen = (size_t)len; 164 165 bufleft = (int)len; 166 } 167 168 buflen *= 2; 169 } 170 } 171 172 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') || 173 (type == RANDOM_TYPE_WORDS && isspace((int)buf[i])) || 174 (eof && i == buflen - 1)) { 175 make_token: 176 n = rand_node_allocate(); 177 if (-1 != (int)i) { 178 slen = i - (u_long)bufc; 179 n->len = slen + 2; 180 n->cp = (u_char *)malloc(slen + 2); 181 if (n->cp == NULL) 182 err(1, "malloc"); 183 184 memmove(n->cp, &buf[bufc], slen); 185 n->cp[slen] = buf[i]; 186 n->cp[slen + 1] = '\0'; 187 bufc = i + 1; 188 } 189 rand_node_append(n); 190 fndstr = 1; 191 numnode++; 192 } 193 } 194 } 195 196 close(fd); 197 198 /* Necessary evil to compensate for files that don't end with a newline */ 199 if (bufc != i) { 200 i--; 201 goto make_token; 202 } 203 204 for (i = numnode; i > 0; i--) { 205 selected = ((int)denom * random())/(((double)RAND_MAX + 1) / numnode); 206 207 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) { 208 if (j == selected) { 209 if (n->cp == NULL) 210 break; 211 212 ret = printf("%.*s", (int)n->len - 1, n->cp); 213 if (ret < 0) 214 err(1, "printf"); 215 if (unique) { 216 if (n == rand_root) 217 rand_root = n->next; 218 if (n == rand_tail) 219 rand_tail = prev; 220 221 prev->next = n->next; 222 rand_node_free(n); 223 numnode--; 224 break; 225 } 226 } 227 } 228 } 229 230 fflush(stdout); 231 232 if (!unique) 233 rand_node_free_rec(rand_root); 234 235 return(0); 236 } 237