seq.c revision 215034 
1/*	$NetBSD: seq.c,v 1.5 2008/07/21 14:19:26 lukem Exp $	*/
2/*
3 * Copyright (c) 2005 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Brian Ginsbach.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.bin/seq/seq.c 215034 2010-11-09 10:59:09Z brucec $");
33
34#include <ctype.h>
35#include <err.h>
36#include <errno.h>
37#include <math.h>
38#include <locale.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#define ZERO	'0'
45#define SPACE	' '
46
47#define MAX(a, b)	(((a) < (b))? (b) : (a))
48#define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
49#define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
50#define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
51
52/* Globals */
53
54const char *decimal_point = ".";	/* default */
55char default_format[] = { "%g" };	/* default */
56
57/* Prototypes */
58
59double e_atof(const char *);
60
61int decimal_places(const char *);
62int main(int, char *[]);
63int numeric(const char *);
64int valid_format(const char *);
65
66char *generate_format(double, double, double, int, char);
67char *unescape(char *);
68
69/*
70 * The seq command will print out a numeric sequence from 1, the default,
71 * to a user specified upper limit by 1.  The lower bound and increment
72 * maybe indicated by the user on the command line.  The sequence can
73 * be either whole, the default, or decimal numbers.
74 */
75int
76main(int argc, char *argv[])
77{
78	int c = 0, errflg = 0;
79	int equalize = 0;
80	double first = 1.0;
81	double last = 0.0;
82	double incr = 0.0;
83	struct lconv *locale;
84	char *fmt = NULL;
85	const char *sep = "\n";
86	const char *term = NULL;
87	char pad = ZERO;
88
89	/* Determine the locale's decimal point. */
90	locale = localeconv();
91	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
92		decimal_point = locale->decimal_point;
93
94	/*
95         * Process options, but handle negative numbers separately
96         * least they trip up getopt(3).
97         */
98	while ((optind < argc) && !numeric(argv[optind]) &&
99	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
100
101		switch (c) {
102		case 'f':	/* format (plan9) */
103			fmt = optarg;
104			equalize = 0;
105			break;
106		case 's':	/* separator (GNU) */
107			sep = unescape(optarg);
108			break;
109		case 't':	/* terminator (new) */
110			term = unescape(optarg);
111			break;
112		case 'w':	/* equal width (plan9) */
113			if (!fmt)
114				if (equalize++)
115					pad = SPACE;
116			break;
117		case 'h':	/* help (GNU) */
118		default:
119			errflg++;
120			break;
121		}
122	}
123
124	argc -= optind;
125	argv += optind;
126	if (argc < 1 || argc > 3)
127		errflg++;
128
129	if (errflg) {
130		fprintf(stderr,
131		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
132		    getprogname());
133		exit(1);
134	}
135
136	last = e_atof(argv[argc - 1]);
137
138	if (argc > 1)
139		first = e_atof(argv[0]);
140
141	if (argc > 2) {
142		incr = e_atof(argv[1]);
143		/* Plan 9/GNU don't do zero */
144		if (incr == 0.0)
145			errx(1, "zero %screment", (first < last)? "in" : "de");
146	}
147
148	/* default is one for Plan 9/GNU work alike */
149	if (incr == 0.0)
150		incr = (first < last) ? 1.0 : -1.0;
151
152	if (incr <= 0.0 && first < last)
153		errx(1, "needs positive increment");
154
155	if (incr >= 0.0 && first > last)
156		errx(1, "needs negative decrement");
157
158	if (fmt != NULL) {
159		if (!valid_format(fmt))
160			errx(1, "invalid format string: `%s'", fmt);
161		fmt = unescape(fmt);
162		/*
163	         * XXX to be bug for bug compatible with Plan 9 add a
164		 * newline if none found at the end of the format string.
165		 */
166	} else
167		fmt = generate_format(first, incr, last, equalize, pad);
168
169	if (incr > 0) {
170		for (; first <= last; first += incr) {
171			printf(fmt, first);
172			fputs(sep, stdout);
173		}
174	} else {
175		for (; first >= last; first += incr) {
176			printf(fmt, first);
177			fputs(sep, stdout);
178		}
179	}
180	if (term != NULL)
181		fputs(term, stdout);
182
183	return (0);
184}
185
186/*
187 * numeric - verify that string is numeric
188 */
189int
190numeric(const char *s)
191{
192	int seen_decimal_pt, decimal_pt_len;
193
194	/* skip any sign */
195	if (ISSIGN((unsigned char)*s))
196		s++;
197
198	seen_decimal_pt = 0;
199	decimal_pt_len = strlen(decimal_point);
200	while (*s) {
201		if (!isdigit((unsigned char)*s)) {
202			if (!seen_decimal_pt &&
203			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
204				s += decimal_pt_len;
205				seen_decimal_pt = 1;
206				continue;
207			}
208			if (ISEXP((unsigned char)*s)) {
209				s++;
210				if (ISSIGN((unsigned char)*s) ||
211				    isdigit((unsigned char)*s)) {
212					s++;
213					continue;
214				}
215			}
216			break;
217		}
218		s++;
219	}
220	return (*s == '\0');
221}
222
223/*
224 * valid_format - validate user specified format string
225 */
226int
227valid_format(const char *fmt)
228{
229	int conversions = 0;
230
231	while (*fmt != '\0') {
232		/* scan for conversions */
233		if (*fmt != '\0' && *fmt != '%') {
234			do {
235				fmt++;
236			} while (*fmt != '\0' && *fmt != '%');
237		}
238		/* scan a conversion */
239		if (*fmt != '\0') {
240			do {
241				fmt++;
242
243				/* ok %% */
244				if (*fmt == '%') {
245					fmt++;
246					break;
247				}
248				/* valid conversions */
249				if (strchr("eEfgG", *fmt) &&
250				    conversions++ < 1) {
251					fmt++;
252					break;
253				}
254				/* flags, width and precision */
255				if (isdigit((unsigned char)*fmt) ||
256				    strchr("+- 0#.", *fmt))
257					continue;
258
259				/* oops! bad conversion format! */
260				return (0);
261			} while (*fmt != '\0');
262		}
263	}
264
265	return (conversions <= 1);
266}
267
268/*
269 * unescape - handle C escapes in a string
270 */
271char *
272unescape(char *orig)
273{
274	char c, *cp, *new = orig;
275	int i;
276
277	for (cp = orig; (*orig = *cp); cp++, orig++) {
278		if (*cp != '\\')
279			continue;
280
281		switch (*++cp) {
282		case 'a':	/* alert (bell) */
283			*orig = '\a';
284			continue;
285		case 'b':	/* backspace */
286			*orig = '\b';
287			continue;
288		case 'e':	/* escape */
289			*orig = '\e';
290			continue;
291		case 'f':	/* formfeed */
292			*orig = '\f';
293			continue;
294		case 'n':	/* newline */
295			*orig = '\n';
296			continue;
297		case 'r':	/* carriage return */
298			*orig = '\r';
299			continue;
300		case 't':	/* horizontal tab */
301			*orig = '\t';
302			continue;
303		case 'v':	/* vertical tab */
304			*orig = '\v';
305			continue;
306		case '\\':	/* backslash */
307			*orig = '\\';
308			continue;
309		case '\'':	/* single quote */
310			*orig = '\'';
311			continue;
312		case '\"':	/* double quote */
313			*orig = '"';
314			continue;
315		case '0':
316		case '1':
317		case '2':
318		case '3':	/* octal */
319		case '4':
320		case '5':
321		case '6':
322		case '7':	/* number */
323			for (i = 0, c = 0;
324			     ISODIGIT((unsigned char)*cp) && i < 3;
325			     i++, cp++) {
326				c <<= 3;
327				c |= (*cp - '0');
328			}
329			*orig = c;
330			--cp;
331			continue;
332		case 'x':	/* hexadecimal number */
333			cp++;	/* skip 'x' */
334			for (i = 0, c = 0;
335			     isxdigit((unsigned char)*cp) && i < 2;
336			     i++, cp++) {
337				c <<= 4;
338				if (isdigit((unsigned char)*cp))
339					c |= (*cp - '0');
340				else
341					c |= ((toupper((unsigned char)*cp) -
342					    'A') + 10);
343			}
344			*orig = c;
345			--cp;
346			continue;
347		default:
348			--cp;
349			break;
350		}
351	}
352
353	return (new);
354}
355
356/*
357 * e_atof - convert an ASCII string to a double
358 *	exit if string is not a valid double, or if converted value would
359 *	cause overflow or underflow
360 */
361double
362e_atof(const char *num)
363{
364	char *endp;
365	double dbl;
366
367	errno = 0;
368	dbl = strtod(num, &endp);
369
370	if (errno == ERANGE)
371		/* under or overflow */
372		err(2, "%s", num);
373	else if (*endp != '\0')
374		/* "junk" left in number */
375		errx(2, "invalid floating point argument: %s", num);
376
377	/* zero shall have no sign */
378	if (dbl == -0.0)
379		dbl = 0;
380	return (dbl);
381}
382
383/*
384 * decimal_places - count decimal places in a number (string)
385 */
386int
387decimal_places(const char *number)
388{
389	int places = 0;
390	char *dp;
391
392	/* look for a decimal point */
393	if ((dp = strstr(number, decimal_point))) {
394		dp += strlen(decimal_point);
395
396		while (isdigit((unsigned char)*dp++))
397			places++;
398	}
399	return (places);
400}
401
402/*
403 * generate_format - create a format string
404 *
405 * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
406 * when "%g" prints as "%e" (this way no width adjustments are made)
407 */
408char *
409generate_format(double first, double incr, double last, int equalize, char pad)
410{
411	static char buf[256];
412	char cc = '\0';
413	int precision, width1, width2, places;
414
415	if (equalize == 0)
416		return (default_format);
417
418	/* figure out "last" value printed */
419	if (first > last)
420		last = first - incr * floor((first - last) / incr);
421	else
422		last = first + incr * floor((last - first) / incr);
423
424	sprintf(buf, "%g", incr);
425	if (strchr(buf, 'e'))
426		cc = 'e';
427	precision = decimal_places(buf);
428
429	width1 = sprintf(buf, "%g", first);
430	if (strchr(buf, 'e'))
431		cc = 'e';
432	if ((places = decimal_places(buf)))
433		width1 -= (places + strlen(decimal_point));
434
435	precision = MAX(places, precision);
436
437	width2 = sprintf(buf, "%g", last);
438	if (strchr(buf, 'e'))
439		cc = 'e';
440	if ((places = decimal_places(buf)))
441		width2 -= (places + strlen(decimal_point));
442
443	if (precision) {
444		sprintf(buf, "%%%c%d.%d%c", pad,
445		    MAX(width1, width2) + (int) strlen(decimal_point) +
446		    precision, precision, (cc) ? cc : 'f');
447	} else {
448		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
449		    (cc) ? cc : 'g');
450	}
451
452	return (buf);
453}
454