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