1/*	$NetBSD: seq.c,v 1.7 2010/05/27 08:40:19 dholland Exp $	*/
2/*-
3 * SPDX-License-Identifier: BSD-2-Clause
4 *
5 * Copyright (c) 2005 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Brian Ginsbach.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34#include <ctype.h>
35#include <err.h>
36#include <errno.h>
37#include <getopt.h>
38#include <math.h>
39#include <locale.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44
45#define ZERO	'0'
46#define SPACE	' '
47
48#define MAX(a, b)	(((a) < (b))? (b) : (a))
49#define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
50#define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
51#define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
52
53/* Globals */
54
55static const char *decimal_point = ".";	/* default */
56static char default_format[] = { "%g" };	/* default */
57
58static const struct option long_opts[] = {
59	{"format",	required_argument,	NULL, 'f'},
60	{"separator",	required_argument,	NULL, 's'},
61	{"terminator",	required_argument,	NULL, 't'},
62	{"equal-width",	no_argument,		NULL, 'w'},
63	{NULL,		no_argument,		NULL, 0}
64};
65
66/* Prototypes */
67
68static double e_atof(const char *);
69
70static int decimal_places(const char *);
71static int numeric(const char *);
72static int valid_format(const char *);
73
74static char *generate_format(double, double, double, int, char);
75static char *unescape(char *);
76
77/*
78 * The seq command will print out a numeric sequence from 1, the default,
79 * to a user specified upper limit by 1.  The lower bound and increment
80 * maybe indicated by the user on the command line.  The sequence can
81 * be either whole, the default, or decimal numbers.
82 */
83int
84main(int argc, char *argv[])
85{
86	const char *sep, *term;
87	struct lconv *locale;
88	char pad, *fmt, *cur_print, *last_print, *prev_print;
89	double first, last, incr, prev, cur, step;
90	int c, errflg, equalize;
91
92	pad = ZERO;
93	fmt = NULL;
94	first = 1.0;
95	last = incr = prev = 0.0;
96	c = errflg = equalize = 0;
97	sep = "\n";
98	term = NULL;
99
100	/* Determine the locale's decimal point. */
101	locale = localeconv();
102	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
103		decimal_point = locale->decimal_point;
104
105	/*
106	 * Process options, but handle negative numbers separately
107	 * least they trip up getopt(3).
108	 */
109	while ((optind < argc) && !numeric(argv[optind]) &&
110	    (c = getopt_long(argc, argv, "+f:hs:t:w", long_opts, NULL)) != -1) {
111
112		switch (c) {
113		case 'f':	/* format (plan9) */
114			fmt = optarg;
115			equalize = 0;
116			break;
117		case 's':	/* separator (GNU) */
118			sep = unescape(optarg);
119			break;
120		case 't':	/* terminator (new) */
121			term = unescape(optarg);
122			break;
123		case 'w':	/* equal width (plan9) */
124			if (!fmt)
125				if (equalize++)
126					pad = SPACE;
127			break;
128		case 'h':	/* help (GNU) */
129		default:
130			errflg++;
131			break;
132		}
133	}
134
135	argc -= optind;
136	argv += optind;
137	if (argc < 1 || argc > 3)
138		errflg++;
139
140	if (errflg) {
141		fprintf(stderr,
142		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
143		    getprogname());
144		exit(1);
145	}
146
147	last = e_atof(argv[argc - 1]);
148
149	if (argc > 1)
150		first = e_atof(argv[0]);
151
152	if (argc > 2) {
153		incr = e_atof(argv[1]);
154		/* Plan 9/GNU don't do zero */
155		if (incr == 0.0)
156			errx(1, "zero %screment", (first < last) ? "in" : "de");
157	}
158
159	/* default is one for Plan 9/GNU work alike */
160	if (incr == 0.0)
161		incr = (first < last) ? 1.0 : -1.0;
162
163	if (incr <= 0.0 && first < last)
164		errx(1, "needs positive increment");
165
166	if (incr >= 0.0 && first > last)
167		errx(1, "needs negative decrement");
168
169	if (fmt != NULL) {
170		if (!valid_format(fmt))
171			errx(1, "invalid format string: `%s'", fmt);
172		fmt = unescape(fmt);
173		if (!valid_format(fmt))
174			errx(1, "invalid format string");
175		/*
176		 * XXX to be bug for bug compatible with Plan 9 add a
177		 * newline if none found at the end of the format string.
178		 */
179	} else
180		fmt = generate_format(first, incr, last, equalize, pad);
181
182	for (step = 1, cur = first; incr > 0 ? cur <= last : cur >= last;
183	    cur = first + incr * step++) {
184		if (step > 1)
185			fputs(sep, stdout);
186		printf(fmt, cur);
187		prev = cur;
188	}
189
190	/*
191	 * Did we miss the last value of the range in the loop above?
192	 *
193	 * We might have, so check if the printable version of the last
194	 * computed value ('cur') and desired 'last' value are equal.  If they
195	 * are equal after formatting truncation, but 'cur' and 'prev' are not
196	 * equal, it means the exit condition of the loop held true due to a
197	 * rounding error and we still need to print 'last'.
198	 */
199	if (asprintf(&cur_print, fmt, cur) < 0 ||
200	    asprintf(&last_print, fmt, last) < 0 ||
201	    asprintf(&prev_print, fmt, prev) < 0) {
202		err(1, "asprintf");
203	}
204	if (strcmp(cur_print, last_print) == 0 &&
205	    strcmp(cur_print, prev_print) != 0) {
206		fputs(sep, stdout);
207		fputs(last_print, stdout);
208	}
209	free(cur_print);
210	free(last_print);
211	free(prev_print);
212
213	if (term != NULL) {
214		fputs(sep, stdout);
215		fputs(term, stdout);
216	}
217
218	fputs("\n", stdout);
219
220	return (0);
221}
222
223/*
224 * numeric - verify that string is numeric
225 */
226static int
227numeric(const char *s)
228{
229	int seen_decimal_pt, decimal_pt_len;
230
231	/* skip any sign */
232	if (ISSIGN((unsigned char)*s))
233		s++;
234
235	seen_decimal_pt = 0;
236	decimal_pt_len = strlen(decimal_point);
237	while (*s) {
238		if (!isdigit((unsigned char)*s)) {
239			if (!seen_decimal_pt &&
240			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
241				s += decimal_pt_len;
242				seen_decimal_pt = 1;
243				continue;
244			}
245			if (ISEXP((unsigned char)*s)) {
246				s++;
247				if (ISSIGN((unsigned char)*s) ||
248				    isdigit((unsigned char)*s)) {
249					s++;
250					continue;
251				}
252			}
253			break;
254		}
255		s++;
256	}
257	return (*s == '\0');
258}
259
260/*
261 * valid_format - validate user specified format string
262 */
263static int
264valid_format(const char *fmt)
265{
266	unsigned conversions = 0;
267
268	while (*fmt != '\0') {
269		/* scan for conversions */
270		if (*fmt != '%') {
271			fmt++;
272			continue;
273		}
274		fmt++;
275
276		/* allow %% but not things like %10% */
277		if (*fmt == '%') {
278			fmt++;
279			continue;
280		}
281
282		/* flags */
283		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
284			fmt++;
285		}
286
287		/* field width */
288		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
289			fmt++;
290		}
291
292		/* precision */
293		if (*fmt == '.') {
294			fmt++;
295			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
296				fmt++;
297			}
298		}
299
300		/* conversion */
301		switch (*fmt) {
302		case 'A':
303		case 'a':
304		case 'E':
305		case 'e':
306		case 'F':
307		case 'f':
308		case 'G':
309		case 'g':
310			/* floating point formats are accepted */
311			conversions++;
312			break;
313		default:
314			/* anything else is not */
315			return 0;
316		}
317	}
318
319	/* PR 236347 -- user format strings must have a conversion */
320	return (conversions == 1);
321}
322
323/*
324 * unescape - handle C escapes in a string
325 */
326static char *
327unescape(char *orig)
328{
329	char c, *cp, *new = orig;
330	int i;
331
332	for (cp = orig; (*orig = *cp); cp++, orig++) {
333		if (*cp != '\\')
334			continue;
335
336		switch (*++cp) {
337		case 'a':	/* alert (bell) */
338			*orig = '\a';
339			continue;
340		case 'b':	/* backspace */
341			*orig = '\b';
342			continue;
343		case 'e':	/* escape */
344			*orig = '\e';
345			continue;
346		case 'f':	/* formfeed */
347			*orig = '\f';
348			continue;
349		case 'n':	/* newline */
350			*orig = '\n';
351			continue;
352		case 'r':	/* carriage return */
353			*orig = '\r';
354			continue;
355		case 't':	/* horizontal tab */
356			*orig = '\t';
357			continue;
358		case 'v':	/* vertical tab */
359			*orig = '\v';
360			continue;
361		case '\\':	/* backslash */
362			*orig = '\\';
363			continue;
364		case '\'':	/* single quote */
365			*orig = '\'';
366			continue;
367		case '\"':	/* double quote */
368			*orig = '"';
369			continue;
370		case '0':
371		case '1':
372		case '2':
373		case '3':	/* octal */
374		case '4':
375		case '5':
376		case '6':
377		case '7':	/* number */
378			for (i = 0, c = 0;
379			     ISODIGIT((unsigned char)*cp) && i < 3;
380			     i++, cp++) {
381				c <<= 3;
382				c |= (*cp - '0');
383			}
384			*orig = c;
385			--cp;
386			continue;
387		case 'x':	/* hexadecimal number */
388			cp++;	/* skip 'x' */
389			for (i = 0, c = 0;
390			     isxdigit((unsigned char)*cp) && i < 2;
391			     i++, cp++) {
392				c <<= 4;
393				if (isdigit((unsigned char)*cp))
394					c |= (*cp - '0');
395				else
396					c |= ((toupper((unsigned char)*cp) -
397					    'A') + 10);
398			}
399			*orig = c;
400			--cp;
401			continue;
402		default:
403			--cp;
404			break;
405		}
406	}
407
408	return (new);
409}
410
411/*
412 * e_atof - convert an ASCII string to a double
413 *	exit if string is not a valid double, or if converted value would
414 *	cause overflow or underflow
415 */
416static double
417e_atof(const char *num)
418{
419	char *endp;
420	double dbl;
421
422	errno = 0;
423	dbl = strtod(num, &endp);
424
425	if (errno == ERANGE)
426		/* under or overflow */
427		err(2, "%s", num);
428	else if (*endp != '\0')
429		/* "junk" left in number */
430		errx(2, "invalid floating point argument: %s", num);
431
432	/* zero shall have no sign */
433	if (dbl == -0.0)
434		dbl = 0;
435	return (dbl);
436}
437
438/*
439 * decimal_places - count decimal places in a number (string)
440 */
441static int
442decimal_places(const char *number)
443{
444	int places = 0;
445	char *dp;
446
447	/* look for a decimal point */
448	if ((dp = strstr(number, decimal_point))) {
449		dp += strlen(decimal_point);
450
451		while (isdigit((unsigned char)*dp++))
452			places++;
453	}
454	return (places);
455}
456
457/*
458 * generate_format - create a format string
459 *
460 * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
461 * when "%g" prints as "%e" (this way no width adjustments are made)
462 */
463static char *
464generate_format(double first, double incr, double last, int equalize, char pad)
465{
466	static char buf[256];
467	char cc = '\0';
468	int precision, width1, width2, places;
469
470	if (equalize == 0)
471		return (default_format);
472
473	/* figure out "last" value printed */
474	if (first > last)
475		last = first - incr * floor((first - last) / incr);
476	else
477		last = first + incr * floor((last - first) / incr);
478
479	sprintf(buf, "%g", incr);
480	if (strchr(buf, 'e'))
481		cc = 'e';
482	precision = decimal_places(buf);
483
484	width1 = sprintf(buf, "%g", first);
485	if (strchr(buf, 'e'))
486		cc = 'e';
487	if ((places = decimal_places(buf)))
488		width1 -= (places + strlen(decimal_point));
489
490	precision = MAX(places, precision);
491
492	width2 = sprintf(buf, "%g", last);
493	if (strchr(buf, 'e'))
494		cc = 'e';
495	if ((places = decimal_places(buf)))
496		width2 -= (places + strlen(decimal_point));
497
498	if (precision) {
499		sprintf(buf, "%%%c%d.%d%c", pad,
500		    MAX(width1, width2) + (int) strlen(decimal_point) +
501		    precision, precision, (cc) ? cc : 'f');
502	} else {
503		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
504		    (cc) ? cc : 'g');
505	}
506
507	return (buf);
508}
509