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      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 1.15 2025/07/09 12:20:31 uwe 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
     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
    100 main(int argc, char *argv[])
    101 {
    102 	int c = 0, errflg = 0;
    103 	int equalize = 0;
    104 	unsigned prec;
    105 	unsigned maxprec = 0;
    106 	double first = 1.0;
    107 	double last = 0.0;
    108 	double incr = 0.0;
    109 	double prev;
    110 	struct lconv *locale;
    111 	char *fmt = NULL;
    112 	const char *sep = "\n";
    113 	const char *term = "\n";
    114 	char pad = ZERO;
    115 	char buf[6]; /* %.MAXPRECISIONf */
    116 
    117 
    118 	/* Determine the locale's decimal point. */
    119 	locale = localeconv();
    120 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
    121 		decimal_point = locale->decimal_point;
    122 
    123 	/*
    124          * Process options, but handle negative numbers separately
    125          * least they trip up getopt(3).
    126          */
    127 	while ((optind < argc) && !numeric(argv[optind]) &&
    128 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
    129 
    130 		switch (c) {
    131 		case 'f':	/* format (plan9) */
    132 			fmt = optarg;
    133 			equalize = 0;
    134 			break;
    135 		case 's':	/* separator (GNU) */
    136 			sep = unescape(optarg);
    137 			break;
    138 		case 't':	/* terminator (new) */
    139 			term = unescape(optarg);
    140 			break;
    141 		case 'w':	/* equal width (plan9) */
    142 			if (!fmt)
    143 				if (equalize++)
    144 					pad = SPACE;
    145 			break;
    146 		case 'h':	/* help (GNU) */
    147 		default:
    148 			errflg++;
    149 			break;
    150 		}
    151 	}
    152 
    153 	argc -= optind;
    154 	argv += optind;
    155 	if (argc < 1 || argc > 3)
    156 		errflg++;
    157 
    158 	if (errflg) {
    159 		fprintf(stderr,
    160 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
    161 		    getprogname());
    162 		exit(1);
    163 	}
    164 
    165 	last = e_atof(argv[argc - 1]);
    166 	maxprec = prec = get_precision(argv[argc - 1], 0);
    167 
    168 	if (argc > 1) {
    169 		first = e_atof(argv[0]);
    170 		prec = get_precision(argv[0], prec);
    171 		if (prec > maxprec)
    172 			maxprec = prec;
    173 	}
    174 
    175 	if (argc > 2) {
    176 		incr = e_atof(argv[1]);
    177 		prec = get_precision(argv[1], prec);
    178 		if (prec > maxprec)
    179 			maxprec = prec;
    180 		/* Plan 9/GNU don't do zero */
    181 		if (incr == 0.0)
    182 			errx(1, "zero %screment", (first < last)? "in" : "de");
    183 	}
    184 
    185 	/* default is one for Plan 9/GNU work alike */
    186 	if (incr == 0.0)
    187 		incr = (first < last) ? 1.0 : -1.0;
    188 
    189 	if (incr <= 0.0 && first < last)
    190 		errx(1, "needs positive increment");
    191 
    192 	if (incr >= 0.0 && first > last)
    193 		errx(1, "needs negative decrement");
    194 
    195 	if (fmt != NULL) {
    196 		if (!valid_format(fmt))
    197 			errx(1, "invalid format string: `%s'", fmt);
    198 		fmt = unescape(fmt);
    199 		if (!valid_format(fmt))
    200 			errx(1, "invalid format string");
    201 		/*
    202 	         * XXX to be bug for bug compatible with Plan 9 add a
    203 		 * newline if none found at the end of the format string.
    204 		 */
    205 	} else {
    206 		if (maxprec == 0)
    207 			fmt = default_format;
    208 		else {
    209 			sprintf(buf, default_format_fmt, maxprec);
    210 			fmt = buf;
    211 		}
    212 		fmt = generate_format(first, incr, last, equalize, pad, fmt);
    213 	}
    214 
    215 	if (incr > 0) {
    216 		printf(fmt, first);
    217 		prev = first;
    218 		for (first += incr; first <= last; first += incr) {
    219 			if (first <= prev)
    220 				errx(1, "increment too small\n");
    221 			fputs(sep, stdout);
    222 			printf(fmt, first);
    223 			prev = first;
    224 		}
    225 	} else {
    226 		printf(fmt, first);
    227 		prev = first;
    228 		for (first += incr; first >= last; first += incr) {
    229 			if (first >= prev)
    230 				errx(1, "increment too small\n");
    231 			fputs(sep, stdout);
    232 			printf(fmt, first);
    233 			prev = first;
    234 		}
    235 	}
    236 	if (term != NULL)
    237 		fputs(term, stdout);
    238 
    239 	return (0);
    240 }
    241 
    242 /*
    243  * numeric - verify that string is numeric
    244  */
    245 int
    246 numeric(const char *s)
    247 {
    248 	int seen_decimal_pt, decimal_pt_len;
    249 
    250 	/* skip any sign */
    251 	if (ISSIGN((unsigned char)*s))
    252 		s++;
    253 
    254 	seen_decimal_pt = 0;
    255 	decimal_pt_len = strlen(decimal_point);
    256 	while (*s) {
    257 		if (!isdigit((unsigned char)*s)) {
    258 			if (!seen_decimal_pt &&
    259 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
    260 				s += decimal_pt_len;
    261 				seen_decimal_pt = 1;
    262 				continue;
    263 			}
    264 			if (ISEXP((unsigned char)*s)) {
    265 				s++;
    266 				/* optional sign */
    267 				if (ISSIGN((unsigned char)*s))
    268 					s++;
    269 				continue;
    270 			}
    271 			break;
    272 		}
    273 		s++;
    274 	}
    275 	return (*s == '\0');
    276 }
    277 
    278 /*
    279  * valid_format - validate user specified format string
    280  */
    281 int
    282 valid_format(const char *fmt)
    283 {
    284 	unsigned conversions = 0;
    285 
    286 	while (*fmt != '\0') {
    287 		/* scan for conversions */
    288 		if (*fmt != '%') {
    289 			fmt++;
    290 			continue;
    291 		}
    292 		fmt++;
    293 
    294 		/* allow %% but not things like %10% */
    295 		if (*fmt == '%') {
    296 			fmt++;
    297 			continue;
    298 		}
    299 
    300 		/* flags */
    301 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
    302 			fmt++;
    303 		}
    304 
    305 		/* field width */
    306 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    307 			fmt++;
    308 		}
    309 
    310 		/* precision */
    311 		if (*fmt == '.') {
    312 			fmt++;
    313 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    314 				fmt++;
    315 			}
    316 		}
    317 
    318 		/* conversion */
    319 		switch (*fmt) {
    320 		    case 'A':
    321 		    case 'a':
    322 		    case 'E':
    323 		    case 'e':
    324 		    case 'F':
    325 		    case 'f':
    326 		    case 'G':
    327 		    case 'g':
    328 			/* floating point formats are accepted */
    329 			conversions++;
    330 			break;
    331 		    default:
    332 			/* anything else is not */
    333 			return 0;
    334 		}
    335 	}
    336 
    337 	return (conversions <= 1);
    338 }
    339 
    340 /*
    341  * unescape - handle C escapes in a string
    342  */
    343 char *
    344 unescape(char *orig)
    345 {
    346 	char c, *cp, *new = orig;
    347 	int i;
    348 
    349 	for (cp = orig; (*orig = *cp); cp++, orig++) {
    350 		if (*cp != '\\')
    351 			continue;
    352 
    353 		switch (*++cp) {
    354 		case 'a':	/* alert (bell) */
    355 			*orig = '\a';
    356 			continue;
    357 		case 'b':	/* backspace */
    358 			*orig = '\b';
    359 			continue;
    360 		case 'e':	/* escape */
    361 			*orig = '\x1B';
    362 			continue;
    363 		case 'f':	/* formfeed */
    364 			*orig = '\f';
    365 			continue;
    366 		case 'n':	/* newline */
    367 			*orig = '\n';
    368 			continue;
    369 		case 'r':	/* carriage return */
    370 			*orig = '\r';
    371 			continue;
    372 		case 't':	/* horizontal tab */
    373 			*orig = '\t';
    374 			continue;
    375 		case 'v':	/* vertical tab */
    376 			*orig = '\v';
    377 			continue;
    378 		case '\\':	/* backslash */
    379 			*orig = '\\';
    380 			continue;
    381 		case '\'':	/* single quote */
    382 			*orig = '\'';
    383 			continue;
    384 		case '\"':	/* double quote */
    385 			*orig = '"';
    386 			continue;
    387 		case '0':
    388 		case '1':
    389 		case '2':
    390 		case '3':	/* octal */
    391 		case '4':
    392 		case '5':
    393 		case '6':
    394 		case '7':	/* number */
    395 			for (i = 0, c = 0;
    396 			     ISODIGIT((unsigned char)*cp) && i < 3;
    397 			     i++, cp++) {
    398 				c <<= 3;
    399 				c |= (*cp - '0');
    400 			}
    401 			*orig = c;
    402 			--cp;
    403 			continue;
    404 		case 'x':	/* hexadecimal number */
    405 			cp++;	/* skip 'x' */
    406 			for (i = 0, c = 0;
    407 			     isxdigit((unsigned char)*cp) && i < 2;
    408 			     i++, cp++) {
    409 				c <<= 4;
    410 				if (isdigit((unsigned char)*cp))
    411 					c |= (*cp - '0');
    412 				else
    413 					c |= ((toupper((unsigned char)*cp) -
    414 					    'A') + 10);
    415 			}
    416 			*orig = c;
    417 			--cp;
    418 			continue;
    419 		default:
    420 			--cp;
    421 			break;
    422 		}
    423 	}
    424 
    425 	return (new);
    426 }
    427 
    428 /*
    429  * e_atof - convert an ASCII string to a double
    430  *	exit if string is not a valid double, or if converted value would
    431  *	cause overflow or underflow
    432  */
    433 double
    434 e_atof(const char *num)
    435 {
    436 	char *endp;
    437 	double dbl;
    438 
    439 	errno = 0;
    440 	dbl = strtod(num, &endp);
    441 
    442 	if (errno == ERANGE)
    443 		/* under or overflow */
    444 		err(2, "%s", num);
    445 	else if (*endp != '\0')
    446 		/* "junk" left in number */
    447 		errx(2, "invalid floating point argument: %s", num);
    448 
    449 	/* zero shall have no sign */
    450 	if (dbl == -0.0)
    451 		dbl = 0;
    452 	return (dbl);
    453 }
    454 
    455 /*
    456  * decimal_places - count decimal places in a number (string)
    457  */
    458 int
    459 decimal_places(const char *number)
    460 {
    461 	int places = 0;
    462 	char *dp;
    463 
    464 	/* look for a decimal point */
    465 	if ((dp = strstr(number, decimal_point))) {
    466 		dp += strlen(decimal_point);
    467 
    468 		while (isdigit((unsigned char)*dp++))
    469 			places++;
    470 	}
    471 	return (places);
    472 }
    473 
    474 /*
    475  * generate_format - create a format string
    476  *
    477  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
    478  * when "%g" prints as "%e" (this way no width adjustments are made)
    479  */
    480 char *
    481 generate_format(double first, double incr, double last,
    482     int equalize, char pad, char *deffmt)
    483 {
    484 	static char buf[256];
    485 	char cc = '\0';
    486 	int precision, width1, width2, places;
    487 
    488 	if (equalize == 0)
    489 		return deffmt;
    490 
    491 	/* figure out "last" value printed */
    492 	if (first > last)
    493 		last = first - incr * floor((first - last) / incr);
    494 	else
    495 		last = first + incr * floor((last - first) / incr);
    496 
    497 	sprintf(buf, deffmt, incr);
    498 	if (strchr(buf, 'e'))
    499 		cc = 'e';
    500 	precision = decimal_places(buf);
    501 
    502 	width1 = sprintf(buf, deffmt, first);
    503 	if (strchr(buf, 'e'))
    504 		cc = 'e';
    505 	if ((places = decimal_places(buf)))
    506 		width1 -= (places + strlen(decimal_point));
    507 
    508 	precision = MAX(places, precision);
    509 
    510 	width2 = sprintf(buf, deffmt, last);
    511 	if (strchr(buf, 'e'))
    512 		cc = 'e';
    513 	if ((places = decimal_places(buf)))
    514 		width2 -= (places + strlen(decimal_point));
    515 
    516 	if (precision) {
    517 		sprintf(buf, "%%%c%d.%d%c", pad,
    518 		    MAX(width1, width2) + (int) strlen(decimal_point) +
    519 		    precision, precision, (cc) ? cc : 'f');
    520 	} else {
    521 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
    522 		    (cc) ? cc : 'g');
    523 	}
    524 
    525 	return (buf);
    526 }
    527