1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Landon Curt Noll.
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/*
34 * primes - generate a table of primes between two values
35 *
36 * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
37 *
38 * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
39 *
40 * usage:
41 *	primes [-h] [start [stop]]
42 *
43 *	Print primes >= start and < stop.  If stop is omitted,
44 *	the value 18446744073709551615 (2^64-1) is assumed.  If
45 *	start is omitted, start is read from standard input.
46 *
47 * validation check: there are 664579 primes between 0 and 10^7
48 */
49
50#include <capsicum_helpers.h>
51#include <ctype.h>
52#include <err.h>
53#include <errno.h>
54#include <inttypes.h>
55#include <limits.h>
56#include <math.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <nl_types.h>
61#include <unistd.h>
62
63#include "primes.h"
64
65/*
66 * Eratosthenes sieve table
67 *
68 * We only sieve the odd numbers.  The base of our sieve windows are always
69 * odd.  If the base of table is 1, table[i] represents 2*i-1.  After the
70 * sieve, table[i] == 1 if and only if 2*i-1 is prime.
71 *
72 * We make TABSIZE large to reduce the overhead of inner loop setup.
73 */
74static char table[TABSIZE];	 /* Eratosthenes sieve of odd numbers */
75
76static int	hflag;
77
78static void	primes(ubig, ubig);
79static ubig	read_num_buf(void);
80static void	usage(void);
81
82int
83main(int argc, char *argv[])
84{
85	ubig start;		/* where to start generating */
86	ubig stop;		/* don't generate at or above this value */
87	int ch;
88	char *p;
89
90	caph_cache_catpages();
91	if (caph_enter() < 0)
92		err(1, "cap_enter");
93
94	while ((ch = getopt(argc, argv, "h")) != -1)
95		switch (ch) {
96		case 'h':
97			hflag++;
98			break;
99		case '?':
100		default:
101			usage();
102		}
103	argc -= optind;
104	argv += optind;
105
106	start = 0;
107	stop = (uint64_t)(-1);
108
109	/*
110	 * Convert low and high args.  Strtoumax(3) sets errno to
111	 * ERANGE if the number is too large, but, if there's
112	 * a leading minus sign it returns the negation of the
113	 * result of the conversion, which we'd rather disallow.
114	 */
115	switch (argc) {
116	case 2:
117		/* Start and stop supplied on the command line. */
118		if (argv[0][0] == '-' || argv[1][0] == '-')
119			errx(1, "negative numbers aren't permitted.");
120
121		errno = 0;
122		start = strtoumax(argv[0], &p, 0);
123		if (errno)
124			err(1, "%s", argv[0]);
125		if (*p != '\0')
126			errx(1, "%s: illegal numeric format.", argv[0]);
127
128		errno = 0;
129		stop = strtoumax(argv[1], &p, 0);
130		if (errno)
131			err(1, "%s", argv[1]);
132		if (*p != '\0')
133			errx(1, "%s: illegal numeric format.", argv[1]);
134		break;
135	case 1:
136		/* Start on the command line. */
137		if (argv[0][0] == '-')
138			errx(1, "negative numbers aren't permitted.");
139
140		errno = 0;
141		start = strtoumax(argv[0], &p, 0);
142		if (errno)
143			err(1, "%s", argv[0]);
144		if (*p != '\0')
145			errx(1, "%s: illegal numeric format.", argv[0]);
146		break;
147	case 0:
148		start = read_num_buf();
149		break;
150	default:
151		usage();
152	}
153
154	if (start > stop)
155		errx(1, "start value must be less than stop value.");
156	primes(start, stop);
157	return (0);
158}
159
160/*
161 * read_num_buf --
162 *	This routine returns a number n, where 0 <= n && n <= BIG.
163 */
164static ubig
165read_num_buf(void)
166{
167	ubig val;
168	char *p, buf[LINE_MAX];		/* > max number of digits. */
169
170	for (;;) {
171		if (fgets(buf, sizeof(buf), stdin) == NULL) {
172			if (ferror(stdin))
173				err(1, "stdin");
174			exit(0);
175		}
176		for (p = buf; isblank(*p); ++p);
177		if (*p == '\n' || *p == '\0')
178			continue;
179		if (*p == '-')
180			errx(1, "negative numbers aren't permitted.");
181		errno = 0;
182		val = strtoumax(buf, &p, 0);
183		if (errno)
184			err(1, "%s", buf);
185		if (*p != '\n')
186			errx(1, "%s: illegal numeric format.", buf);
187		return (val);
188	}
189}
190
191/*
192 * primes - sieve and print primes from start up to and but not including stop
193 */
194static void
195primes(ubig start, ubig stop)
196{
197	char *q;		/* sieve spot */
198	ubig factor;		/* index and factor */
199	char *tab_lim;		/* the limit to sieve on the table */
200	const ubig *p;		/* prime table pointer */
201	ubig fact_lim;		/* highest prime for current block */
202	ubig mod;		/* temp storage for mod */
203
204	/*
205	 * A number of systems can not convert double values into unsigned
206	 * longs when the values are larger than the largest signed value.
207	 * We don't have this problem, so we can go all the way to BIG.
208	 */
209	if (start < 3) {
210		start = (ubig)2;
211	}
212	if (stop < 3) {
213		stop = (ubig)2;
214	}
215	if (stop <= start) {
216		return;
217	}
218
219	/*
220	 * be sure that the values are odd, or 2
221	 */
222	if (start != 2 && (start&0x1) == 0) {
223		++start;
224	}
225	if (stop != 2 && (stop&0x1) == 0) {
226		++stop;
227	}
228
229	/*
230	 * quick list of primes <= pr_limit
231	 */
232	if (start <= *pr_limit) {
233		/* skip primes up to the start value */
234		for (p = &prime[0], factor = prime[0];
235		    factor < stop && p <= pr_limit; factor = *(++p)) {
236			if (factor >= start) {
237				printf(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\n", factor);
238			}
239		}
240		/* return early if we are done */
241		if (p <= pr_limit) {
242			return;
243		}
244		start = *pr_limit+2;
245	}
246
247	/*
248	 * we shall sieve a bytemap window, note primes and move the window
249	 * upward until we pass the stop point
250	 */
251	while (start < stop) {
252		/*
253		 * factor out 3, 5, 7, 11 and 13
254		 */
255		/* initial pattern copy */
256		factor = (start%(2*3*5*7*11*13))/2; /* starting copy spot */
257		memcpy(table, &pattern[factor], pattern_size-factor);
258		/* main block pattern copies */
259		for (fact_lim=pattern_size-factor;
260		    fact_lim+pattern_size<=TABSIZE; fact_lim+=pattern_size) {
261			memcpy(&table[fact_lim], pattern, pattern_size);
262		}
263		/* final block pattern copy */
264		memcpy(&table[fact_lim], pattern, TABSIZE-fact_lim);
265
266		/*
267		 * sieve for primes 17 and higher
268		 */
269		/* note highest useful factor and sieve spot */
270		if (stop-start > TABSIZE+TABSIZE) {
271			tab_lim = &table[TABSIZE]; /* sieve it all */
272			fact_lim = sqrt(start+1.0+TABSIZE+TABSIZE);
273		} else {
274			tab_lim = &table[(stop-start)/2]; /* partial sieve */
275			fact_lim = sqrt(stop+1.0);
276		}
277		/* sieve for factors >= 17 */
278		factor = 17;	/* 17 is first prime to use */
279		p = &prime[7];	/* 19 is next prime, pi(19)=7 */
280		do {
281			/* determine the factor's initial sieve point */
282			mod = start%factor;
283			if (mod & 0x1) {
284				q = &table[(factor-mod)/2];
285			} else {
286				q = &table[mod ? factor-(mod/2) : 0];
287			}
288			/* sive for our current factor */
289			for ( ; q < tab_lim; q += factor) {
290				*q = '\0'; /* sieve out a spot */
291			}
292			factor = *p++;
293		} while (factor <= fact_lim);
294
295		/*
296		 * print generated primes
297		 */
298		for (q = table; q < tab_lim; ++q, start+=2) {
299			if (*q) {
300				if (start > SIEVEMAX) {
301					if (!isprime(start))
302						continue;
303				}
304				printf(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\n", start);
305			}
306		}
307	}
308}
309
310static void
311usage(void)
312{
313	fprintf(stderr, "usage: primes [-h] [start [stop]]\n");
314	exit(1);
315}
316