+/* $NetBSD: primes.c,v 1.22 2018/02/03 15:40:29 christos Exp $ */
+
/*
- * Copyright (c) 1989 The Regents of the University of California.
- * All rights reserved.
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Landon Curt Noll.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* SUCH DAMAGE.
*/
+#include <sys/cdefs.h>
#ifndef lint
-char copyright[] =
-"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
- All rights reserved.\n";
+__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
+ The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
-/*static char sccsid[] = "from: @(#)primes.c 5.4 (Berkeley) 6/1/90";*/
-static char rcsid[] = "$Id: primes.c,v 1.2 1993/08/01 18:53:04 mycroft Exp $";
+#if 0
+static char sccsid[] = "@(#)primes.c 8.5 (Berkeley) 5/10/95";
+#else
+__RCSID("$NetBSD: primes.c,v 1.22 2018/02/03 15:40:29 christos Exp $");
+#endif
#endif /* not lint */
/*
* primes - generate a table of primes between two values
*
- * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
- *
- * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
+ * By Landon Curt Noll, http://www.isthe.com/chongo/index.html /\oo/\
*
* usage:
- * primes [start [stop]]
+ * primes [-dh] [start [stop]]
*
* Print primes >= start and < stop. If stop is omitted,
- * the value 4294967295 (2^32-1) is assumed. If start is
+ * the value SPSPMAX is assumed. If start is
* omitted, start is read from standard input.
- *
- * Prints "ouch" if start or stop is bogus.
+ * -d: print difference to previous prime, e.g. 3 (1)
+ * -h: print primes in hexadecimal
*
* validation check: there are 664579 primes between 0 and 10^7
*/
-#include <stdio.h>
-#include <math.h>
-#include <memory.h>
#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
#include "primes.h"
/*
*
* We only sieve the odd numbers. The base of our sieve windows are always
* odd. If the base of table is 1, table[i] represents 2*i-1. After the
- * sieve, table[i] == 1 if and only iff 2*i-1 is prime.
+ * sieve, table[i] == 1 if and only if 2*i-1 is prime.
*
* We make TABSIZE large to reduce the overhead of inner loop setup.
*/
-char table[TABSIZE]; /* Eratosthenes sieve of odd numbers */
+static char table[TABSIZE]; /* Eratosthenes sieve of odd numbers */
-/*
- * prime[i] is the (i-1)th prime.
- *
- * We are able to sieve 2^32-1 because this byte table yields all primes
- * up to 65537 and 65537^2 > 2^32-1.
- */
-extern ubig prime[];
-extern ubig *pr_limit; /* largest prime in the prime array */
+static int dflag, hflag;
-/*
- * To avoid excessive sieves for small factors, we use the table below to
- * setup our sieve blocks. Each element represents a odd number starting
- * with 1. All non-zero elements are factors of 3, 5, 7, 11 and 13.
- */
-extern char pattern[];
-extern int pattern_size; /* length of pattern array */
+static void primes(uint64_t, uint64_t);
+static uint64_t read_num_buf(void);
+static void usage(void) __dead;
-#define MAX_LINE 255 /* max line allowed on stdin */
-char *read_num_buf(); /* read a number buffer */
-void primes(); /* print the primes in range */
-char *program; /* our name */
-
-main(argc, argv)
- int argc; /* arg count */
- char *argv[]; /* args */
+int
+main(int argc, char *argv[])
{
- char buf[MAX_LINE+1]; /* input buffer */
- char *ret; /* return result */
- ubig start; /* where to start generating */
- ubig stop; /* don't generate at or above this value */
-
- /*
- * parse args
- */
- program = argv[0];
- start = 0;
- stop = BIG;
- if (argc == 3) {
- /* convert low and high args */
- if (read_num_buf(NULL, argv[1]) == NULL) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- if (read_num_buf(NULL, argv[2]) == NULL) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- if (sscanf(argv[1], "%ld", &start) != 1) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- if (sscanf(argv[2], "%ld", &stop) != 1) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
-
- } else if (argc == 2) {
- /* convert low arg */
- if (read_num_buf(NULL, argv[1]) == NULL) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- if (sscanf(argv[1], "%ld", &start) != 1) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
+ uint64_t start; /* where to start generating */
+ uint64_t stop; /* don't generate at or above this value */
+ int ch;
+ char *p;
+
+ while ((ch = getopt(argc, argv, "dh")) != -1)
+ switch (ch) {
+ case 'd':
+ dflag++;
+ break;
+ case 'h':
+ hflag++;
+ break;
+ case '?':
+ default:
+ usage();
}
+ argc -= optind;
+ argv += optind;
- } else {
- /* read input until we get a good line */
- if (read_num_buf(stdin, buf) != NULL) {
+ start = 0;
+ stop = (uint64_t)(-1);
- /* convert the buffer */
- if (sscanf(buf, "%ld", &start) != 1) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- } else {
- exit(0);
- }
- }
- if (start > stop) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
+ /*
+ * Convert low and high args. Strtoumax(3) sets errno to
+ * ERANGE if the number is too large, but, if there's
+ * a leading minus sign it returns the negation of the
+ * result of the conversion, which we'd rather disallow.
+ */
+ switch (argc) {
+ case 2:
+ /* Start and stop supplied on the command line. */
+ if (argv[0][0] == '-' || argv[1][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+
+ errno = 0;
+ start = strtoumax(argv[0], &p, 0);
+ if (errno)
+ err(1, "%s", argv[0]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[0]);
+
+ errno = 0;
+ stop = strtoumax(argv[1], &p, 0);
+ if (errno)
+ err(1, "%s", argv[1]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[1]);
+ break;
+ case 1:
+ /* Start on the command line. */
+ if (argv[0][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+
+ errno = 0;
+ start = strtoumax(argv[0], &p, 0);
+ if (errno)
+ err(1, "%s", argv[0]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[0]);
+ break;
+ case 0:
+ start = read_num_buf();
+ break;
+ default:
+ usage();
}
+
+ if (start > stop)
+ errx(1, "start value must be less than stop value.");
primes(start, stop);
- exit(0);
+ return (0);
}
/*
- * read_num_buf - read a number buffer from a stream
- *
- * Read a number on a line of the form:
- *
- * ^[ \t]*\(+?[0-9][0-9]\)*.*$
- *
- * where ? is a 1-or-0 operator and the number is within \( \).
- *
- * If does not match the above pattern, it is ignored and a new
- * line is read. If the number is too large or small, we will
- * print ouch and read a new line.
- *
- * We have to be very careful on how we check the magnitude of the
- * input. We can not use numeric checks because of the need to
- * check values against maximum numeric values.
- *
- * This routine will return a line containing a ascii number between
- * 0 and BIG, or it will return NULL.
- *
- * If the stream is NULL then buf will be processed as if were
- * a single line stream.
- *
- * returns:
- * char * pointer to leading digit or +
- * NULL EOF or error
+ * read_num_buf --
+ * This routine returns a number n, where 0 <= n && n <= ULONG_MAX.
*/
-char *
-read_num_buf(input, buf)
- FILE *input; /* input stream or NULL */
- char *buf; /* input buffer */
+static uint64_t
+read_num_buf(void)
{
- static char limit[MAX_LINE+1]; /* ascii value of BIG */
- static int limit_len; /* digit count of limit */
- int len; /* digits in input (excluding +/-) */
- char *s; /* line start marker */
- char *d; /* first digit, skip +/- */
- char *p; /* scan pointer */
- char *z; /* zero scan pointer */
-
- /* form the ascii value of SEMIBIG if needed */
- if (!isascii(limit[0]) || !isdigit(limit[0])) {
- sprintf(limit, "%ld", SEMIBIG);
- limit_len = strlen(limit);
- }
-
- /*
- * the search for a good line
- */
- if (input != NULL && fgets(buf, MAX_LINE, input) == NULL) {
- /* error or EOF */
- return NULL;
- }
- do {
-
- /* ignore leading whitespace */
- for (s=buf; *s && s < buf+MAX_LINE; ++s) {
- if (!isascii(*s) || !isspace(*s)) {
- break;
- }
- }
-
- /* object if - */
- if (*s == '-') {
- fprintf(stderr, "%s: ouch\n", program);
- continue;
- }
-
- /* skip over any leading + */
- if (*s == '+') {
- d = s+1;
- } else {
- d = s;
- }
+ uint64_t val;
+ char *p, buf[LINE_MAX]; /* > max number of digits. */
- /* note leading zeros */
- for (z=d; *z && z < buf+MAX_LINE; ++z) {
- if (*z != '0') {
- break;
- }
- }
-
- /* scan for the first non-digit/non-plus/non-minus */
- for (p=d; *p && p < buf+MAX_LINE; ++p) {
- if (!isascii(*p) || !isdigit(*p)) {
- break;
- }
- }
-
- /* ignore empty lines */
- if (p == d) {
- continue;
+ for (;;) {
+ if (fgets(buf, sizeof(buf), stdin) == NULL) {
+ if (ferror(stdin))
+ err(1, "stdin");
+ exit(0);
}
- *p = '\0';
-
- /* object if too many digits */
- len = strlen(z);
- len = (len<=0) ? 1 : len;
- /* accept if digit count is below limit */
- if (len < limit_len) {
- /* we have good input */
- return s;
-
- /* reject very large numbers */
- } else if (len > limit_len) {
- fprintf(stderr, "%s: ouch\n", program);
- continue;
-
- /* carefully check against near limit numbers */
- } else if (strcmp(z, limit) > 0) {
- fprintf(stderr, "%s: ouch\n", program);
+ for (p = buf; isblank((unsigned char)*p); ++p);
+ if (*p == '\n' || *p == '\0')
continue;
- }
- /* number is near limit, but is under it */
- return s;
- } while (input != NULL && fgets(buf, MAX_LINE, input) != NULL);
-
- /* error or EOF */
- return NULL;
+ if (*p == '-')
+ errx(1, "negative numbers aren't permitted.");
+ errno = 0;
+ val = strtoumax(buf, &p, 0);
+ if (errno)
+ err(1, "%s", buf);
+ if (*p != '\n')
+ errx(1, "%s: illegal numeric format.", buf);
+ return (val);
+ }
}
/*
* primes - sieve and print primes from start up to and but not including stop
*/
-void
-primes(start, stop)
- ubig start; /* where to start generating */
- ubig stop; /* don't generate at or above this value */
+static void
+primes(uint64_t start, uint64_t stop)
{
- register char *q; /* sieve spot */
- register ubig factor; /* index and factor */
- register char *tab_lim; /* the limit to sieve on the table */
- register ubig *p; /* prime table pointer */
- register ubig fact_lim; /* highest prime for current block */
+ char *q; /* sieve spot */
+ uint64_t factor; /* index and factor */
+ char *tab_lim; /* the limit to sieve on the table */
+ const uint64_t *p; /* prime table pointer */
+ uint64_t fact_lim; /* highest prime for current block */
+ uint64_t mod; /* temp storage for mod */
+ uint64_t prev = 0;
/*
- * A number of systems can not convert double values
- * into unsigned longs when the values are larger than
- * the largest signed value. Thus we take case when
- * the double is larger than the value SEMIBIG. *sigh*
+ * A number of systems can not convert double values into unsigned
+ * longs when the values are larger than the largest signed value.
+ * We don't have this problem, so we can go all the way to ULONG_MAX.
*/
if (start < 3) {
- start = (ubig)2;
+ start = 2;
}
if (stop < 3) {
- stop = (ubig)2;
+ stop = 2;
}
if (stop <= start) {
return;
if (start <= *pr_limit) {
/* skip primes up to the start value */
for (p = &prime[0], factor = prime[0];
- factor < stop && p <= pr_limit;
- factor = *(++p)) {
+ factor < stop && p <= pr_limit; factor = *(++p)) {
if (factor >= start) {
- printf("%u\n", factor);
+ printf(hflag ? "%" PRIx64 : "%" PRIu64, factor);
+ if (dflag) {
+ printf(" (%" PRIu64 ")", factor - prev);
+ }
+ putchar('\n');
}
+ prev = factor;
}
/* return early if we are done */
if (p <= pr_limit) {
memcpy(table, &pattern[factor], pattern_size-factor);
/* main block pattern copies */
for (fact_lim=pattern_size-factor;
- fact_lim+pattern_size<=TABSIZE;
- fact_lim+=pattern_size) {
+ fact_lim+pattern_size<=TABSIZE; fact_lim+=pattern_size) {
memcpy(&table[fact_lim], pattern, pattern_size);
}
/* final block pattern copy */
/* note highest useful factor and sieve spot */
if (stop-start > TABSIZE+TABSIZE) {
tab_lim = &table[TABSIZE]; /* sieve it all */
- fact_lim = (int)sqrt(
- (double)(start)+TABSIZE+TABSIZE+1.0);
+ fact_lim = sqrt(start+1.0+TABSIZE+TABSIZE);
} else {
tab_lim = &table[(stop-start)/2]; /* partial sieve */
- fact_lim = (int)sqrt((double)(stop)+1.0);
+ fact_lim = sqrt(stop+1.0);
}
/* sieve for factors >= 17 */
factor = 17; /* 17 is first prime to use */
p = &prime[7]; /* 19 is next prime, pi(19)=7 */
do {
/* determine the factor's initial sieve point */
- q = (char *)(start%factor); /* temp storage for mod */
- if ((int)q & 0x1) {
- q = &table[(factor-(int)q)/2];
+ mod = start%factor;
+ if (mod & 0x1) {
+ q = &table[(factor-mod)/2];
} else {
- q = &table[q ? factor-((int)q/2) : 0];
+ q = &table[mod ? factor-(mod/2) : 0];
}
- /* sive for our current factor */
+ /* sieve for our current factor */
for ( ; q < tab_lim; q += factor) {
*q = '\0'; /* sieve out a spot */
}
- } while ((factor=(ubig)(*(p++))) <= fact_lim);
+ factor = *p++;
+ } while (factor <= fact_lim);
/*
* print generated primes
*/
for (q = table; q < tab_lim; ++q, start+=2) {
if (*q) {
- printf("%u\n", start);
+ if (start > SIEVEMAX) {
+ if (!isprime(start))
+ continue;
+ }
+ printf(hflag ? "%" PRIx64 : "%" PRIu64, start);
+ if (dflag && (prev || (start <= *pr_limit))) {
+ printf(" (%" PRIu64 ")", start - prev);
+ }
+ putchar('\n');
+ prev = start;
}
}
}
}
+
+static void
+usage(void)
+{
+ (void)fprintf(stderr, "usage: primes [-dh] [start [stop]]\n");
+ exit(1);
+}
git.ckatri.com / bsdgames-darwin.git / blobdiff