+/* $NetBSD: factor.c,v 1.7 1997/10/10 12:51:32 lukem 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.
* 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\n\
+ The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
#ifndef lint
-/*static char sccsid[] = "from: @(#)factor.c 4.4 (Berkeley) 6/1/90";*/
-static char rcsid[] = "$Id: factor.c,v 1.2 1993/08/01 18:54:58 mycroft Exp $";
+#if 0
+static char sccsid[] = "@(#)factor.c 8.4 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: factor.c,v 1.7 1997/10/10 12:51:32 lukem Exp $");
+#endif
#endif /* not lint */
/*
* If no args are given, the list of numbers are read from stdin.
*/
-#include <stdio.h>
+#include <err.h>
#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
#include "primes.h"
/*
* up to 65537 and 65537^2 > 2^32-1.
*/
extern ubig prime[];
-extern ubig *pr_limit; /* largest prime in the prime array */
-
-#define MAX_LINE 255 /* max line allowed on stdin */
+extern ubig *pr_limit; /* largest prime in the prime array */
-void pr_fact(); /* print factors of a value */
-long small_fact(); /* find smallest factor of a value */
-char *read_num_buf(); /* read a number buffer */
-char *program; /* name of this program */
+int main __P((int, char *[]));
+void pr_fact __P((ubig)); /* print factors of a value */
+void usage __P((void));
+int
main(argc, argv)
- int argc; /* arg count */
- char *argv[]; /* the args */
+ int argc;
+ char *argv[];
{
- int arg; /* which arg to factor */
- long val; /* the value to factor */
- char buf[MAX_LINE+1]; /* input buffer */
-
- /* parse args */
- program = argv[0];
- if (argc >= 2) {
-
- /* factor each arg */
- for (arg=1; arg < argc; ++arg) {
-
- /* process the buffer */
- if (read_num_buf(NULL, argv[arg]) == NULL) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
-
- /* factor the argument */
- if (sscanf(argv[arg], "%ld", &val) == 1) {
- pr_fact(val);
- } else {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
+ ubig val;
+ int ch;
+ char *p, buf[100]; /* > max number of digits. */
+
+ while ((ch = getopt(argc, argv, "")) != -1)
+ switch (ch) {
+ case '?':
+ default:
+ usage();
}
-
- /* no args supplied, read numbers from stdin */
- } else {
- /*
- * read asciii numbers from input
- */
- while (read_num_buf(stdin, buf) != NULL) {
-
- /* factor the argument */
- if (sscanf(buf, "%ld", &val) == 1) {
- pr_fact(val);
+ argc -= optind;
+ argv += optind;
+
+ /* No args supplied, read numbers from stdin. */
+ if (argc == 0)
+ for (;;) {
+ if (fgets(buf, sizeof(buf), stdin) == NULL) {
+ if (ferror(stdin))
+ err(1, "stdin");
+ exit (0);
}
+ for (p = buf; isblank(*p); ++p);
+ if (*p == '\n' || *p == '\0')
+ continue;
+ if (*p == '-')
+ errx(1, "negative numbers aren't permitted.");
+ errno = 0;
+ val = strtoul(buf, &p, 10);
+ if (errno)
+ err(1, "%s", buf);
+ if (*p != '\n')
+ errx(1, "%s: illegal numeric format.", buf);
+ pr_fact(val);
}
- }
- exit(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
- * NEG_SEMIBIG and SEMIBIG, 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
- */
-char *
-read_num_buf(input, buf)
- FILE *input; /* input stream or NULL */
- char *buf; /* input buffer */
-{
- static char limit[MAX_LINE+1]; /* ascii value of SEMIBIG */
- static int limit_len; /* digit count of limit */
- static char neg_limit[MAX_LINE+1]; /* value of NEG_SEMIBIG */
- static int neg_limit_len; /* digit count of neg_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);
- sprintf(neg_limit, "%ld", NEG_SEMIBIG);
- neg_limit_len = strlen(neg_limit)-1; /* exclude - */
- }
-
- /*
- * 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;
- }
+ /* Factor the arguments. */
+ else
+ for (; *argv != NULL; ++argv) {
+ if (argv[0][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+ errno = 0;
+ val = strtoul(argv[0], &p, 10);
+ if (errno)
+ err(1, "%s", argv[0]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[0]);
+ pr_fact(val);
}
-
- /* skip over any leading + or - */
- if (*s == '+' || *s == '-') {
- d = s+1;
- } else {
- d = s;
- }
-
- /* note leading zeros */
- for (z=d; *z && z < buf+MAX_LINE; ++z) {
- if (*z != '0') {
- break;
- }
- }
-
- /* scan for the first non-digit */
- for (p=d; *p && p < buf+MAX_LINE; ++p) {
- if (!isascii(*p) || !isdigit(*p)) {
- break;
- }
- }
-
- /* ignore empty lines */
- if (p == d) {
- continue;
- }
- *p = '\0';
-
- /* object if too many digits */
- len = strlen(z);
- len = (len<=0) ? 1 : len;
- if (*s == '-') {
- /* accept if digit count is below limit */
- if (len < neg_limit_len) {
- /* we have good input */
- return s;
-
- /* reject very large numbers */
- } else if (len > neg_limit_len) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
-
- /* carefully check against near limit numbers */
- } else if (strcmp(z, neg_limit+1) > 0) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- /* number is near limit, but is under it */
- return s;
-
- } else {
- /* 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);
- exit(1);
-
- /* carefully check against near limit numbers */
- } else if (strcmp(z, limit) > 0) {
- fprintf(stderr, "%s: ouch\n", program);
- exit(1);
- }
- /* number is near limit, but is under it */
- return s;
- }
- } while (input != NULL && fgets(buf, MAX_LINE, input) != NULL);
-
- /* error or EOF */
- return NULL;
+ exit(0);
}
-
/*
* pr_fact - print the factors of a number
*
*/
void
pr_fact(val)
- long val; /* factor this value */
+ ubig val; /* Factor this value. */
{
- ubig *fact; /* the factor found */
+ ubig *fact; /* The factor found. */
- /* firewall - catch 0 and 1 */
- switch (val) {
- case -2147483648:
- /* avoid negation problems */
- puts("-2147483648: -1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2\n");
- return;
- case -1:
- puts("-1: -1\n");
- return;
- case 0:
+ /* Firewall - catch 0 and 1. */
+ if (val == 0) /* Historical practice; 0 just exits. */
exit(0);
- case 1:
- puts("1: 1\n");
+ if (val == 1) {
+ (void)printf("1: 1\n");
return;
- default:
- if (val < 0) {
- val = -val;
- printf("%ld: -1", val);
- } else {
- printf("%ld:", val);
- }
- fflush(stdout);
- break;
}
- /*
- * factor value
- */
- fact = &prime[0];
- while (val > 1) {
-
- /* look for the smallest factor */
+ /* Factor value. */
+ (void)printf("%lu:", val);
+ for (fact = &prime[0]; val > 1; ++fact) {
+ /* Look for the smallest factor. */
do {
- if (val%(long)*fact == 0) {
+ if (val % (long)*fact == 0)
break;
- }
} while (++fact <= pr_limit);
- /* watch for primes larger than the table */
+ /* Watch for primes larger than the table. */
if (fact > pr_limit) {
- printf(" %ld\n", val);
- return;
+ (void)printf(" %lu", val);
+ break;
}
- /* divide factor out until none are left */
+ /* Divide factor out until none are left. */
do {
- printf(" %ld", *fact);
+ (void)printf(" %lu", *fact);
val /= (long)*fact;
} while ((val % (long)*fact) == 0);
- fflush(stdout);
- ++fact;
+
+ /* Let the user know we're doing something. */
+ (void)fflush(stdout);
}
- putchar('\n');
- return;
+ (void)putchar('\n');
+}
+
+void
+usage()
+{
+ (void)fprintf(stderr, "usage: factor [value ...]\n");
+ exit (0);
}
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