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seq.c revision 1.14 
      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
     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 	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
    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
    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 *
    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
    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
    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 *
    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