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#ifndef lint
34static const char copyright[] =
35"@(#) Copyright (c) 1989, 1993\n\
36	The Regents of the University of California.  All rights reserved.\n";
37#endif /* not lint */
38
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)primes.c	8.5 (Berkeley) 5/10/95";
42#endif
43static const char rcsid[] =
44 "$FreeBSD$";
45#endif /* not lint */
46
47/*
48 * primes - generate a table of primes between two values
49 *
50 * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
51 *
52 * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
53 *
54 * usage:
55 *	primes [-h] [start [stop]]
56 *
57 *	Print primes >= start and < stop.  If stop is omitted,
58 *	the value 18446744073709551615 (2^64-1) is assumed.  If
59 *	start is omitted, start is read from standard input.
60 *
61 * validation check: there are 664579 primes between 0 and 10^7
62 */
63
64#include <capsicum_helpers.h>
65#include <ctype.h>
66#include <err.h>
67#include <errno.h>
68#include <inttypes.h>
69#include <limits.h>
70#include <math.h>
71#include <stdio.h>
72#include <stdlib.h>
73#include <string.h>
74#include <nl_types.h>
75#include <unistd.h>
76
77#include "primes.h"
78
79/*
80 * Eratosthenes sieve table
81 *
82 * We only sieve the odd numbers.  The base of our sieve windows are always
83 * odd.  If the base of table is 1, table[i] represents 2*i-1.  After the
84 * sieve, table[i] == 1 if and only if 2*i-1 is prime.
85 *
86 * We make TABSIZE large to reduce the overhead of inner loop setup.
87 */
88static char table[TABSIZE];	 /* Eratosthenes sieve of odd numbers */
89
90static int	hflag;
91
92static void	primes(ubig, ubig);
93static ubig	read_num_buf(void);
94static void	usage(void);
95
96int
97main(int argc, char *argv[])
98{
99	ubig start;		/* where to start generating */
100	ubig stop;		/* don't generate at or above this value */
101	int ch;
102	char *p;
103
104	caph_cache_catpages();
105	if (caph_enter() < 0)
106		err(1, "cap_enter");
107
108	while ((ch = getopt(argc, argv, "h")) != -1)
109		switch (ch) {
110		case 'h':
111			hflag++;
112			break;
113		case '?':
114		default:
115			usage();
116		}
117	argc -= optind;
118	argv += optind;
119
120	start = 0;
121	stop = (uint64_t)(-1);
122
123	/*
124	 * Convert low and high args.  Strtoumax(3) sets errno to
125	 * ERANGE if the number is too large, but, if there's
126	 * a leading minus sign it returns the negation of the
127	 * result of the conversion, which we'd rather disallow.
128	 */
129	switch (argc) {
130	case 2:
131		/* Start and stop supplied on the command line. */
132		if (argv[0][0] == '-' || argv[1][0] == '-')
133			errx(1, "negative numbers aren't permitted.");
134
135		errno = 0;
136		start = strtoumax(argv[0], &p, 0);
137		if (errno)
138			err(1, "%s", argv[0]);
139		if (*p != '\0')
140			errx(1, "%s: illegal numeric format.", argv[0]);
141
142		errno = 0;
143		stop = strtoumax(argv[1], &p, 0);
144		if (errno)
145			err(1, "%s", argv[1]);
146		if (*p != '\0')
147			errx(1, "%s: illegal numeric format.", argv[1]);
148		break;
149	case 1:
150		/* Start on the command line. */
151		if (argv[0][0] == '-')
152			errx(1, "negative numbers aren't permitted.");
153
154		errno = 0;
155		start = strtoumax(argv[0], &p, 0);
156		if (errno)
157			err(1, "%s", argv[0]);
158		if (*p != '\0')
159			errx(1, "%s: illegal numeric format.", argv[0]);
160		break;
161	case 0:
162		start = read_num_buf();
163		break;
164	default:
165		usage();
166	}
167
168	if (start > stop)
169		errx(1, "start value must be less than stop value.");
170	primes(start, stop);
171	return (0);
172}
173
174/*
175 * read_num_buf --
176 *	This routine returns a number n, where 0 <= n && n <= BIG.
177 */
178static ubig
179read_num_buf(void)
180{
181	ubig val;
182	char *p, buf[LINE_MAX];		/* > max number of digits. */
183
184	for (;;) {
185		if (fgets(buf, sizeof(buf), stdin) == NULL) {
186			if (ferror(stdin))
187				err(1, "stdin");
188			exit(0);
189		}
190		for (p = buf; isblank(*p); ++p);
191		if (*p == '\n' || *p == '\0')
192			continue;
193		if (*p == '-')
194			errx(1, "negative numbers aren't permitted.");
195		errno = 0;
196		val = strtoumax(buf, &p, 0);
197		if (errno)
198			err(1, "%s", buf);
199		if (*p != '\n')
200			errx(1, "%s: illegal numeric format.", buf);
201		return (val);
202	}
203}
204
205/*
206 * primes - sieve and print primes from start up to and but not including stop
207 */
208static void
209primes(ubig start, ubig stop)
210{
211	char *q;		/* sieve spot */
212	ubig factor;		/* index and factor */
213	char *tab_lim;		/* the limit to sieve on the table */
214	const ubig *p;		/* prime table pointer */
215	ubig fact_lim;		/* highest prime for current block */
216	ubig mod;		/* temp storage for mod */
217
218	/*
219	 * A number of systems can not convert double values into unsigned
220	 * longs when the values are larger than the largest signed value.
221	 * We don't have this problem, so we can go all the way to BIG.
222	 */
223	if (start < 3) {
224		start = (ubig)2;
225	}
226	if (stop < 3) {
227		stop = (ubig)2;
228	}
229	if (stop <= start) {
230		return;
231	}
232
233	/*
234	 * be sure that the values are odd, or 2
235	 */
236	if (start != 2 && (start&0x1) == 0) {
237		++start;
238	}
239	if (stop != 2 && (stop&0x1) == 0) {
240		++stop;
241	}
242
243	/*
244	 * quick list of primes <= pr_limit
245	 */
246	if (start <= *pr_limit) {
247		/* skip primes up to the start value */
248		for (p = &prime[0], factor = prime[0];
249		    factor < stop && p <= pr_limit; factor = *(++p)) {
250			if (factor >= start) {
251				printf(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\n", factor);
252			}
253		}
254		/* return early if we are done */
255		if (p <= pr_limit) {
256			return;
257		}
258		start = *pr_limit+2;
259	}
260
261	/*
262	 * we shall sieve a bytemap window, note primes and move the window
263	 * upward until we pass the stop point
264	 */
265	while (start < stop) {
266		/*
267		 * factor out 3, 5, 7, 11 and 13
268		 */
269		/* initial pattern copy */
270		factor = (start%(2*3*5*7*11*13))/2; /* starting copy spot */
271		memcpy(table, &pattern[factor], pattern_size-factor);
272		/* main block pattern copies */
273		for (fact_lim=pattern_size-factor;
274		    fact_lim+pattern_size<=TABSIZE; fact_lim+=pattern_size) {
275			memcpy(&table[fact_lim], pattern, pattern_size);
276		}
277		/* final block pattern copy */
278		memcpy(&table[fact_lim], pattern, TABSIZE-fact_lim);
279
280		/*
281		 * sieve for primes 17 and higher
282		 */
283		/* note highest useful factor and sieve spot */
284		if (stop-start > TABSIZE+TABSIZE) {
285			tab_lim = &table[TABSIZE]; /* sieve it all */
286			fact_lim = sqrt(start+1.0+TABSIZE+TABSIZE);
287		} else {
288			tab_lim = &table[(stop-start)/2]; /* partial sieve */
289			fact_lim = sqrt(stop+1.0);
290		}
291		/* sieve for factors >= 17 */
292		factor = 17;	/* 17 is first prime to use */
293		p = &prime[7];	/* 19 is next prime, pi(19)=7 */
294		do {
295			/* determine the factor's initial sieve point */
296			mod = start%factor;
297			if (mod & 0x1) {
298				q = &table[(factor-mod)/2];
299			} else {
300				q = &table[mod ? factor-(mod/2) : 0];
301			}
302			/* sive for our current factor */
303			for ( ; q < tab_lim; q += factor) {
304				*q = '\0'; /* sieve out a spot */
305			}
306			factor = *p++;
307		} while (factor <= fact_lim);
308
309		/*
310		 * print generated primes
311		 */
312		for (q = table; q < tab_lim; ++q, start+=2) {
313			if (*q) {
314				if (start > SIEVEMAX) {
315					if (!isprime(start))
316						continue;
317				}
318				printf(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\n", start);
319			}
320		}
321	}
322}
323
324static void
325usage(void)
326{
327	fprintf(stderr, "usage: primes [-h] [start [stop]]\n");
328	exit(1);
329}
330