2 * Copyright (C) 2003 Sean Chittenden <seanc@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/games/random/randomize_fd.c,v 1.2.2.1 2003/02/15 10:34:35 seanc Exp $
29 #include <sys/types.h>
30 #include <sys/param.h>
39 #include "randomize_fd.h"
41 static struct rand_node *rand_root;
42 static struct rand_node *rand_tail;
44 static struct rand_node *
45 rand_node_allocate(void)
49 n = (struct rand_node *)malloc(sizeof(struct rand_node));
60 rand_node_free(struct rand_node *n)
71 rand_node_free_rec(struct rand_node *n)
75 rand_node_free_rec(n->next);
82 rand_node_append(struct rand_node *n)
84 if (rand_root == NULL)
85 rand_root = rand_tail = n;
93 randomize_fd(int fd, int type, int unique, double denom)
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;
102 rand_root = rand_tail = NULL;
104 bufleft = eof = fndstr = numnode = ret = 0;
106 if (type == RANDOM_TYPE_UNSET)
107 type = RANDOM_TYPE_LINES;
109 buflen = sizeof(u_char) * MAXBSIZE;
110 buf = (u_char *)malloc(buflen);
115 /* Check to see if we have bits in the buffer */
117 len = read(fd, buf, buflen);
123 } else if ((size_t)len < buflen)
124 buflen = (size_t)len;
129 /* Look for a newline */
130 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) {
134 memmove(buf, &buf[bufc], i - bufc);
137 len = read(fd, &buf[i], buflen - i);
143 } else if (len < (ssize_t)(buflen - i))
144 buflen = i + (size_t)len;
150 p = (u_char *)realloc(buf, buflen * 2);
156 len = read(fd, &buf[i], buflen);
162 } else if (len < (ssize_t)(buflen - i))
163 buflen = (size_t)len;
172 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') ||
173 (type == RANDOM_TYPE_WORDS && isspace((int)buf[i])) ||
174 (eof && i == buflen - 1)) {
176 n = rand_node_allocate();
178 slen = i - (u_long)bufc;
180 n->cp = (u_char *)malloc(slen + 2);
184 memmove(n->cp, &buf[bufc], slen);
185 n->cp[slen] = buf[i];
186 n->cp[slen + 1] = '\0';
198 /* Necessary evil to compensate for files that don't end with a newline */
204 for (i = numnode; i > 0; i--) {
205 selected = ((int)denom * random())/(((double)RAND_MAX + 1) / numnode);
207 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) {
212 ret = printf("%.*s", (int)n->len - 1, n->cp);
221 prev->next = n->next;
233 rand_node_free_rec(rand_root);