xref: /netbsd-src/usr.bin/seq/seq.c (revision c2c241e6a627d1c0c295f0b0b2a08ace8399c557)
1 /*
2  * Copyright (c) 2005 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Brian Ginsbach.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __COPYRIGHT("@(#) Copyright (c) 2005\
33  The NetBSD Foundation, Inc.  All rights reserved.");
34 __RCSID("$NetBSD: seq.c,v 1.14 2024/05/04 13:29:41 mlelstv Exp $");
35 #endif /* not lint */
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.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 const char *decimal_point = ".";	/* default */
58 char default_format[] = { "%g" };	/* default */
59 char default_format_fmt[] = { "%%.%uf" };
60 #define MAXPRECISION 40
61 
62 /* Prototypes */
63 
64 double e_atof(const char *);
65 
66 int decimal_places(const char *);
67 int numeric(const char *);
68 int valid_format(const char *);
69 
70 unsigned get_precision(const char *, unsigned);
71 char *generate_format(double, double, double, int, char, char *);
72 char *unescape(char *);
73 
74 unsigned
get_precision(const char * number,unsigned minprec)75 get_precision(const char *number, unsigned minprec)
76 {
77 	const char *p;
78 	unsigned prec;
79 
80 	p = strstr(number, decimal_point);
81 	if (p) {
82 		prec = strlen(number) - (p - number);
83 		if (prec > 0)
84 			prec -= 1;
85 		if (prec > MAXPRECISION)
86 			prec = MAXPRECISION;
87 	} else
88 		prec = 0;
89 
90 	return prec < minprec ? minprec : prec;
91 }
92 
93 /*
94  * The seq command will print out a numeric sequence from 1, the default,
95  * to a user specified upper limit by 1.  The lower bound and increment
96  * maybe indicated by the user on the command line.  The sequence can
97  * be either whole, the default, or decimal numbers.
98  */
99 int
main(int argc,char * argv[])100 main(int argc, char *argv[])
101 {
102 	int c = 0, errflg = 0;
103 	int equalize = 0;
104 	unsigned prec;
105 	double first = 1.0;
106 	double last = 0.0;
107 	double incr = 0.0;
108 	double prev;
109 	struct lconv *locale;
110 	char *fmt = NULL;
111 	const char *sep = "\n";
112 	const char *term = "\n";
113 	char pad = ZERO;
114 	char buf[6]; /* %.MAXPRECISIONf */
115 
116 
117 	/* Determine the locale's decimal point. */
118 	locale = localeconv();
119 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
120 		decimal_point = locale->decimal_point;
121 
122 	/*
123          * Process options, but handle negative numbers separately
124          * least they trip up getopt(3).
125          */
126 	while ((optind < argc) && !numeric(argv[optind]) &&
127 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
128 
129 		switch (c) {
130 		case 'f':	/* format (plan9) */
131 			fmt = optarg;
132 			equalize = 0;
133 			break;
134 		case 's':	/* separator (GNU) */
135 			sep = unescape(optarg);
136 			break;
137 		case 't':	/* terminator (new) */
138 			term = unescape(optarg);
139 			break;
140 		case 'w':	/* equal width (plan9) */
141 			if (!fmt)
142 				if (equalize++)
143 					pad = SPACE;
144 			break;
145 		case 'h':	/* help (GNU) */
146 		default:
147 			errflg++;
148 			break;
149 		}
150 	}
151 
152 	argc -= optind;
153 	argv += optind;
154 	if (argc < 1 || argc > 3)
155 		errflg++;
156 
157 	if (errflg) {
158 		fprintf(stderr,
159 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
160 		    getprogname());
161 		exit(1);
162 	}
163 
164 	last = e_atof(argv[argc - 1]);
165 	prec = get_precision(argv[argc - 1], 0);
166 
167 	if (argc > 1) {
168 		first = e_atof(argv[0]);
169 		prec = get_precision(argv[0], prec);
170 	}
171 
172 	if (argc > 2) {
173 		incr = e_atof(argv[1]);
174 		prec = get_precision(argv[1], prec);
175 		/* Plan 9/GNU don't do zero */
176 		if (incr == 0.0)
177 			errx(1, "zero %screment", (first < last)? "in" : "de");
178 	}
179 
180 	/* default is one for Plan 9/GNU work alike */
181 	if (incr == 0.0)
182 		incr = (first < last) ? 1.0 : -1.0;
183 
184 	if (incr <= 0.0 && first < last)
185 		errx(1, "needs positive increment");
186 
187 	if (incr >= 0.0 && first > last)
188 		errx(1, "needs negative decrement");
189 
190 	if (fmt != NULL) {
191 		if (!valid_format(fmt))
192 			errx(1, "invalid format string: `%s'", fmt);
193 		fmt = unescape(fmt);
194 		if (!valid_format(fmt))
195 			errx(1, "invalid format string");
196 		/*
197 	         * XXX to be bug for bug compatible with Plan 9 add a
198 		 * newline if none found at the end of the format string.
199 		 */
200 	} else {
201 		if (prec == 0)
202 			fmt = default_format;
203 		else {
204 			sprintf(buf, default_format_fmt, prec);
205 			fmt = buf;
206 		}
207 		fmt = generate_format(first, incr, last, equalize, pad, fmt);
208 	}
209 
210 	if (incr > 0) {
211 		printf(fmt, first);
212 		prev = first;
213 		for (first += incr; first <= last; first += incr) {
214 			if (first <= prev)
215 				errx(1, "increment too small\n");
216 			fputs(sep, stdout);
217 			printf(fmt, first);
218 			prev = first;
219 		}
220 	} else {
221 		printf(fmt, first);
222 		prev = first;
223 		for (first += incr; first >= last; first += incr) {
224 			if (first >= prev)
225 				errx(1, "increment too small\n");
226 			fputs(sep, stdout);
227 			printf(fmt, first);
228 			prev = first;
229 		}
230 	}
231 	if (term != NULL)
232 		fputs(term, stdout);
233 
234 	return (0);
235 }
236 
237 /*
238  * numeric - verify that string is numeric
239  */
240 int
numeric(const char * s)241 numeric(const char *s)
242 {
243 	int seen_decimal_pt, decimal_pt_len;
244 
245 	/* skip any sign */
246 	if (ISSIGN((unsigned char)*s))
247 		s++;
248 
249 	seen_decimal_pt = 0;
250 	decimal_pt_len = strlen(decimal_point);
251 	while (*s) {
252 		if (!isdigit((unsigned char)*s)) {
253 			if (!seen_decimal_pt &&
254 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
255 				s += decimal_pt_len;
256 				seen_decimal_pt = 1;
257 				continue;
258 			}
259 			if (ISEXP((unsigned char)*s)) {
260 				s++;
261 				/* optional sign */
262 				if (ISSIGN((unsigned char)*s))
263 					s++;
264 				continue;
265 			}
266 			break;
267 		}
268 		s++;
269 	}
270 	return (*s == '\0');
271 }
272 
273 /*
274  * valid_format - validate user specified format string
275  */
276 int
valid_format(const char * fmt)277 valid_format(const char *fmt)
278 {
279 	unsigned conversions = 0;
280 
281 	while (*fmt != '\0') {
282 		/* scan for conversions */
283 		if (*fmt != '%') {
284 			fmt++;
285 			continue;
286 		}
287 		fmt++;
288 
289 		/* allow %% but not things like %10% */
290 		if (*fmt == '%') {
291 			fmt++;
292 			continue;
293 		}
294 
295 		/* flags */
296 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
297 			fmt++;
298 		}
299 
300 		/* field width */
301 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
302 			fmt++;
303 		}
304 
305 		/* precision */
306 		if (*fmt == '.') {
307 			fmt++;
308 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
309 				fmt++;
310 			}
311 		}
312 
313 		/* conversion */
314 		switch (*fmt) {
315 		    case 'A':
316 		    case 'a':
317 		    case 'E':
318 		    case 'e':
319 		    case 'F':
320 		    case 'f':
321 		    case 'G':
322 		    case 'g':
323 			/* floating point formats are accepted */
324 			conversions++;
325 			break;
326 		    default:
327 			/* anything else is not */
328 			return 0;
329 		}
330 	}
331 
332 	return (conversions <= 1);
333 }
334 
335 /*
336  * unescape - handle C escapes in a string
337  */
338 char *
unescape(char * orig)339 unescape(char *orig)
340 {
341 	char c, *cp, *new = orig;
342 	int i;
343 
344 	for (cp = orig; (*orig = *cp); cp++, orig++) {
345 		if (*cp != '\\')
346 			continue;
347 
348 		switch (*++cp) {
349 		case 'a':	/* alert (bell) */
350 			*orig = '\a';
351 			continue;
352 		case 'b':	/* backspace */
353 			*orig = '\b';
354 			continue;
355 		case 'e':	/* escape */
356 			*orig = '\x1B';
357 			continue;
358 		case 'f':	/* formfeed */
359 			*orig = '\f';
360 			continue;
361 		case 'n':	/* newline */
362 			*orig = '\n';
363 			continue;
364 		case 'r':	/* carriage return */
365 			*orig = '\r';
366 			continue;
367 		case 't':	/* horizontal tab */
368 			*orig = '\t';
369 			continue;
370 		case 'v':	/* vertical tab */
371 			*orig = '\v';
372 			continue;
373 		case '\\':	/* backslash */
374 			*orig = '\\';
375 			continue;
376 		case '\'':	/* single quote */
377 			*orig = '\'';
378 			continue;
379 		case '\"':	/* double quote */
380 			*orig = '"';
381 			continue;
382 		case '0':
383 		case '1':
384 		case '2':
385 		case '3':	/* octal */
386 		case '4':
387 		case '5':
388 		case '6':
389 		case '7':	/* number */
390 			for (i = 0, c = 0;
391 			     ISODIGIT((unsigned char)*cp) && i < 3;
392 			     i++, cp++) {
393 				c <<= 3;
394 				c |= (*cp - '0');
395 			}
396 			*orig = c;
397 			--cp;
398 			continue;
399 		case 'x':	/* hexadecimal number */
400 			cp++;	/* skip 'x' */
401 			for (i = 0, c = 0;
402 			     isxdigit((unsigned char)*cp) && i < 2;
403 			     i++, cp++) {
404 				c <<= 4;
405 				if (isdigit((unsigned char)*cp))
406 					c |= (*cp - '0');
407 				else
408 					c |= ((toupper((unsigned char)*cp) -
409 					    'A') + 10);
410 			}
411 			*orig = c;
412 			--cp;
413 			continue;
414 		default:
415 			--cp;
416 			break;
417 		}
418 	}
419 
420 	return (new);
421 }
422 
423 /*
424  * e_atof - convert an ASCII string to a double
425  *	exit if string is not a valid double, or if converted value would
426  *	cause overflow or underflow
427  */
428 double
e_atof(const char * num)429 e_atof(const char *num)
430 {
431 	char *endp;
432 	double dbl;
433 
434 	errno = 0;
435 	dbl = strtod(num, &endp);
436 
437 	if (errno == ERANGE)
438 		/* under or overflow */
439 		err(2, "%s", num);
440 	else if (*endp != '\0')
441 		/* "junk" left in number */
442 		errx(2, "invalid floating point argument: %s", num);
443 
444 	/* zero shall have no sign */
445 	if (dbl == -0.0)
446 		dbl = 0;
447 	return (dbl);
448 }
449 
450 /*
451  * decimal_places - count decimal places in a number (string)
452  */
453 int
decimal_places(const char * number)454 decimal_places(const char *number)
455 {
456 	int places = 0;
457 	char *dp;
458 
459 	/* look for a decimal point */
460 	if ((dp = strstr(number, decimal_point))) {
461 		dp += strlen(decimal_point);
462 
463 		while (isdigit((unsigned char)*dp++))
464 			places++;
465 	}
466 	return (places);
467 }
468 
469 /*
470  * generate_format - create a format string
471  *
472  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
473  * when "%g" prints as "%e" (this way no width adjustments are made)
474  */
475 char *
generate_format(double first,double incr,double last,int equalize,char pad,char * deffmt)476 generate_format(double first, double incr, double last,
477     int equalize, char pad, char *deffmt)
478 {
479 	static char buf[256];
480 	char cc = '\0';
481 	int precision, width1, width2, places;
482 
483 	if (equalize == 0)
484 		return deffmt;
485 
486 	/* figure out "last" value printed */
487 	if (first > last)
488 		last = first - incr * floor((first - last) / incr);
489 	else
490 		last = first + incr * floor((last - first) / incr);
491 
492 	sprintf(buf, deffmt, incr);
493 	if (strchr(buf, 'e'))
494 		cc = 'e';
495 	precision = decimal_places(buf);
496 
497 	width1 = sprintf(buf, deffmt, first);
498 	if (strchr(buf, 'e'))
499 		cc = 'e';
500 	if ((places = decimal_places(buf)))
501 		width1 -= (places + strlen(decimal_point));
502 
503 	precision = MAX(places, precision);
504 
505 	width2 = sprintf(buf, deffmt, last);
506 	if (strchr(buf, 'e'))
507 		cc = 'e';
508 	if ((places = decimal_places(buf)))
509 		width2 -= (places + strlen(decimal_point));
510 
511 	if (precision) {
512 		sprintf(buf, "%%%c%d.%d%c", pad,
513 		    MAX(width1, width2) + (int) strlen(decimal_point) +
514 		    precision, precision, (cc) ? cc : 'f');
515 	} else {
516 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
517 		    (cc) ? cc : 'g');
518 	}
519 
520 	return (buf);
521 }
522