xref: /freebsd/usr.bin/seq/seq.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
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 __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 
57 static const char *decimal_point = ".";	/* default */
58 static char default_format[] = { "%g" };	/* default */
59 
60 static const struct option long_opts[] = {
61 	{"format",	required_argument,	NULL, 'f'},
62 	{"separator",	required_argument,	NULL, 's'},
63 	{"terminator",	required_argument,	NULL, 't'},
64 	{"equal-width",	no_argument,		NULL, 'w'},
65 	{NULL,		no_argument,		NULL, 0}
66 };
67 
68 /* Prototypes */
69 
70 static double e_atof(const char *);
71 
72 static int decimal_places(const char *);
73 static int numeric(const char *);
74 static int valid_format(const char *);
75 
76 static char *generate_format(double, double, double, int, char);
77 static char *unescape(char *);
78 
79 /*
80  * The seq command will print out a numeric sequence from 1, the default,
81  * to a user specified upper limit by 1.  The lower bound and increment
82  * maybe indicated by the user on the command line.  The sequence can
83  * be either whole, the default, or decimal numbers.
84  */
85 int
86 main(int argc, char *argv[])
87 {
88 	const char *sep, *term;
89 	struct lconv *locale;
90 	char pad, *fmt, *cur_print, *last_print, *prev_print;
91 	double first, last, incr, prev, cur, step;
92 	int c, errflg, equalize;
93 
94 	pad = ZERO;
95 	fmt = NULL;
96 	first = 1.0;
97 	last = incr = prev = 0.0;
98 	c = errflg = equalize = 0;
99 	sep = "\n";
100 	term = NULL;
101 
102 	/* Determine the locale's decimal point. */
103 	locale = localeconv();
104 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
105 		decimal_point = locale->decimal_point;
106 
107 	/*
108 	 * Process options, but handle negative numbers separately
109 	 * least they trip up getopt(3).
110 	 */
111 	while ((optind < argc) && !numeric(argv[optind]) &&
112 	    (c = getopt_long(argc, argv, "+f:hs:t:w", long_opts, NULL)) != -1) {
113 
114 		switch (c) {
115 		case 'f':	/* format (plan9) */
116 			fmt = optarg;
117 			equalize = 0;
118 			break;
119 		case 's':	/* separator (GNU) */
120 			sep = unescape(optarg);
121 			break;
122 		case 't':	/* terminator (new) */
123 			term = unescape(optarg);
124 			break;
125 		case 'w':	/* equal width (plan9) */
126 			if (!fmt)
127 				if (equalize++)
128 					pad = SPACE;
129 			break;
130 		case 'h':	/* help (GNU) */
131 		default:
132 			errflg++;
133 			break;
134 		}
135 	}
136 
137 	argc -= optind;
138 	argv += optind;
139 	if (argc < 1 || argc > 3)
140 		errflg++;
141 
142 	if (errflg) {
143 		fprintf(stderr,
144 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
145 		    getprogname());
146 		exit(1);
147 	}
148 
149 	last = e_atof(argv[argc - 1]);
150 
151 	if (argc > 1)
152 		first = e_atof(argv[0]);
153 
154 	if (argc > 2) {
155 		incr = e_atof(argv[1]);
156 		/* Plan 9/GNU don't do zero */
157 		if (incr == 0.0)
158 			errx(1, "zero %screment", (first < last) ? "in" : "de");
159 	}
160 
161 	/* default is one for Plan 9/GNU work alike */
162 	if (incr == 0.0)
163 		incr = (first < last) ? 1.0 : -1.0;
164 
165 	if (incr <= 0.0 && first < last)
166 		errx(1, "needs positive increment");
167 
168 	if (incr >= 0.0 && first > last)
169 		errx(1, "needs negative decrement");
170 
171 	if (fmt != NULL) {
172 		if (!valid_format(fmt))
173 			errx(1, "invalid format string: `%s'", fmt);
174 		fmt = unescape(fmt);
175 		if (!valid_format(fmt))
176 			errx(1, "invalid format string");
177 		/*
178 		 * XXX to be bug for bug compatible with Plan 9 add a
179 		 * newline if none found at the end of the format string.
180 		 */
181 	} else
182 		fmt = generate_format(first, incr, last, equalize, pad);
183 
184 	for (step = 1, cur = first; incr > 0 ? cur <= last : cur >= last;
185 	    cur = first + incr * step++) {
186 		printf(fmt, cur);
187 		fputs(sep, stdout);
188 		prev = cur;
189 	}
190 
191 	/*
192 	 * Did we miss the last value of the range in the loop above?
193 	 *
194 	 * We might have, so check if the printable version of the last
195 	 * computed value ('cur') and desired 'last' value are equal.  If they
196 	 * are equal after formatting truncation, but 'cur' and 'prev' are not
197 	 * equal, it means the exit condition of the loop held true due to a
198 	 * rounding error and we still need to print 'last'.
199 	 */
200 	if (asprintf(&cur_print, fmt, cur) < 0 ||
201 	    asprintf(&last_print, fmt, last) < 0 ||
202 	    asprintf(&prev_print, fmt, prev) < 0) {
203 		err(1, "asprintf");
204 	}
205 	if (strcmp(cur_print, last_print) == 0 &&
206 	    strcmp(cur_print, prev_print) != 0) {
207 		fputs(last_print, stdout);
208 		fputs(sep, stdout);
209 	}
210 	free(cur_print);
211 	free(last_print);
212 	free(prev_print);
213 
214 	if (term != NULL)
215 		fputs(term, stdout);
216 
217 	return (0);
218 }
219 
220 /*
221  * numeric - verify that string is numeric
222  */
223 static int
224 numeric(const char *s)
225 {
226 	int seen_decimal_pt, decimal_pt_len;
227 
228 	/* skip any sign */
229 	if (ISSIGN((unsigned char)*s))
230 		s++;
231 
232 	seen_decimal_pt = 0;
233 	decimal_pt_len = strlen(decimal_point);
234 	while (*s) {
235 		if (!isdigit((unsigned char)*s)) {
236 			if (!seen_decimal_pt &&
237 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
238 				s += decimal_pt_len;
239 				seen_decimal_pt = 1;
240 				continue;
241 			}
242 			if (ISEXP((unsigned char)*s)) {
243 				s++;
244 				if (ISSIGN((unsigned char)*s) ||
245 				    isdigit((unsigned char)*s)) {
246 					s++;
247 					continue;
248 				}
249 			}
250 			break;
251 		}
252 		s++;
253 	}
254 	return (*s == '\0');
255 }
256 
257 /*
258  * valid_format - validate user specified format string
259  */
260 static int
261 valid_format(const char *fmt)
262 {
263 	unsigned conversions = 0;
264 
265 	while (*fmt != '\0') {
266 		/* scan for conversions */
267 		if (*fmt != '%') {
268 			fmt++;
269 			continue;
270 		}
271 		fmt++;
272 
273 		/* allow %% but not things like %10% */
274 		if (*fmt == '%') {
275 			fmt++;
276 			continue;
277 		}
278 
279 		/* flags */
280 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
281 			fmt++;
282 		}
283 
284 		/* field width */
285 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
286 			fmt++;
287 		}
288 
289 		/* precision */
290 		if (*fmt == '.') {
291 			fmt++;
292 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
293 				fmt++;
294 			}
295 		}
296 
297 		/* conversion */
298 		switch (*fmt) {
299 		case 'A':
300 		case 'a':
301 		case 'E':
302 		case 'e':
303 		case 'F':
304 		case 'f':
305 		case 'G':
306 		case 'g':
307 			/* floating point formats are accepted */
308 			conversions++;
309 			break;
310 		default:
311 			/* anything else is not */
312 			return 0;
313 		}
314 	}
315 
316 	/* PR 236347 -- user format strings must have a conversion */
317 	return (conversions == 1);
318 }
319 
320 /*
321  * unescape - handle C escapes in a string
322  */
323 static char *
324 unescape(char *orig)
325 {
326 	char c, *cp, *new = orig;
327 	int i;
328 
329 	for (cp = orig; (*orig = *cp); cp++, orig++) {
330 		if (*cp != '\\')
331 			continue;
332 
333 		switch (*++cp) {
334 		case 'a':	/* alert (bell) */
335 			*orig = '\a';
336 			continue;
337 		case 'b':	/* backspace */
338 			*orig = '\b';
339 			continue;
340 		case 'e':	/* escape */
341 			*orig = '\e';
342 			continue;
343 		case 'f':	/* formfeed */
344 			*orig = '\f';
345 			continue;
346 		case 'n':	/* newline */
347 			*orig = '\n';
348 			continue;
349 		case 'r':	/* carriage return */
350 			*orig = '\r';
351 			continue;
352 		case 't':	/* horizontal tab */
353 			*orig = '\t';
354 			continue;
355 		case 'v':	/* vertical tab */
356 			*orig = '\v';
357 			continue;
358 		case '\\':	/* backslash */
359 			*orig = '\\';
360 			continue;
361 		case '\'':	/* single quote */
362 			*orig = '\'';
363 			continue;
364 		case '\"':	/* double quote */
365 			*orig = '"';
366 			continue;
367 		case '0':
368 		case '1':
369 		case '2':
370 		case '3':	/* octal */
371 		case '4':
372 		case '5':
373 		case '6':
374 		case '7':	/* number */
375 			for (i = 0, c = 0;
376 			     ISODIGIT((unsigned char)*cp) && i < 3;
377 			     i++, cp++) {
378 				c <<= 3;
379 				c |= (*cp - '0');
380 			}
381 			*orig = c;
382 			--cp;
383 			continue;
384 		case 'x':	/* hexadecimal number */
385 			cp++;	/* skip 'x' */
386 			for (i = 0, c = 0;
387 			     isxdigit((unsigned char)*cp) && i < 2;
388 			     i++, cp++) {
389 				c <<= 4;
390 				if (isdigit((unsigned char)*cp))
391 					c |= (*cp - '0');
392 				else
393 					c |= ((toupper((unsigned char)*cp) -
394 					    'A') + 10);
395 			}
396 			*orig = c;
397 			--cp;
398 			continue;
399 		default:
400 			--cp;
401 			break;
402 		}
403 	}
404 
405 	return (new);
406 }
407 
408 /*
409  * e_atof - convert an ASCII string to a double
410  *	exit if string is not a valid double, or if converted value would
411  *	cause overflow or underflow
412  */
413 static double
414 e_atof(const char *num)
415 {
416 	char *endp;
417 	double dbl;
418 
419 	errno = 0;
420 	dbl = strtod(num, &endp);
421 
422 	if (errno == ERANGE)
423 		/* under or overflow */
424 		err(2, "%s", num);
425 	else if (*endp != '\0')
426 		/* "junk" left in number */
427 		errx(2, "invalid floating point argument: %s", num);
428 
429 	/* zero shall have no sign */
430 	if (dbl == -0.0)
431 		dbl = 0;
432 	return (dbl);
433 }
434 
435 /*
436  * decimal_places - count decimal places in a number (string)
437  */
438 static int
439 decimal_places(const char *number)
440 {
441 	int places = 0;
442 	char *dp;
443 
444 	/* look for a decimal point */
445 	if ((dp = strstr(number, decimal_point))) {
446 		dp += strlen(decimal_point);
447 
448 		while (isdigit((unsigned char)*dp++))
449 			places++;
450 	}
451 	return (places);
452 }
453 
454 /*
455  * generate_format - create a format string
456  *
457  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
458  * when "%g" prints as "%e" (this way no width adjustments are made)
459  */
460 static char *
461 generate_format(double first, double incr, double last, int equalize, char pad)
462 {
463 	static char buf[256];
464 	char cc = '\0';
465 	int precision, width1, width2, places;
466 
467 	if (equalize == 0)
468 		return (default_format);
469 
470 	/* figure out "last" value printed */
471 	if (first > last)
472 		last = first - incr * floor((first - last) / incr);
473 	else
474 		last = first + incr * floor((last - first) / incr);
475 
476 	sprintf(buf, "%g", incr);
477 	if (strchr(buf, 'e'))
478 		cc = 'e';
479 	precision = decimal_places(buf);
480 
481 	width1 = sprintf(buf, "%g", first);
482 	if (strchr(buf, 'e'))
483 		cc = 'e';
484 	if ((places = decimal_places(buf)))
485 		width1 -= (places + strlen(decimal_point));
486 
487 	precision = MAX(places, precision);
488 
489 	width2 = sprintf(buf, "%g", last);
490 	if (strchr(buf, 'e'))
491 		cc = 'e';
492 	if ((places = decimal_places(buf)))
493 		width2 -= (places + strlen(decimal_point));
494 
495 	if (precision) {
496 		sprintf(buf, "%%%c%d.%d%c", pad,
497 		    MAX(width1, width2) + (int) strlen(decimal_point) +
498 		    precision, precision, (cc) ? cc : 'f');
499 	} else {
500 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
501 		    (cc) ? cc : 'g');
502 	}
503 
504 	return (buf);
505 }
506