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seq.c revision 1.13 
      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 1.13 2024/02/24 10:10:04 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 	struct lconv *locale;
    109 	char *fmt = NULL;
    110 	const char *sep = "\n";
    111 	const char *term = "\n";
    112 	char pad = ZERO;
    113 	char buf[6]; /* %.MAXPRECISIONf */
    114 
    115 
    116 	/* Determine the locale's decimal point. */
    117 	locale = localeconv();
    118 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
    119 		decimal_point = locale->decimal_point;
    120 
    121 	/*
    122          * Process options, but handle negative numbers separately
    123          * least they trip up getopt(3).
    124          */
    125 	while ((optind < argc) && !numeric(argv[optind]) &&
    126 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
    127 
    128 		switch (c) {
    129 		case 'f':	/* format (plan9) */
    130 			fmt = optarg;
    131 			equalize = 0;
    132 			break;
    133 		case 's':	/* separator (GNU) */
    134 			sep = unescape(optarg);
    135 			break;
    136 		case 't':	/* terminator (new) */
    137 			term = unescape(optarg);
    138 			break;
    139 		case 'w':	/* equal width (plan9) */
    140 			if (!fmt)
    141 				if (equalize++)
    142 					pad = SPACE;
    143 			break;
    144 		case 'h':	/* help (GNU) */
    145 		default:
    146 			errflg++;
    147 			break;
    148 		}
    149 	}
    150 
    151 	argc -= optind;
    152 	argv += optind;
    153 	if (argc < 1 || argc > 3)
    154 		errflg++;
    155 
    156 	if (errflg) {
    157 		fprintf(stderr,
    158 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
    159 		    getprogname());
    160 		exit(1);
    161 	}
    162 
    163 	last = e_atof(argv[argc - 1]);
    164 	prec = get_precision(argv[argc - 1], 0);
    165 
    166 	if (argc > 1) {
    167 		first = e_atof(argv[0]);
    168 		prec = get_precision(argv[0], prec);
    169 	}
    170 
    171 	if (argc > 2) {
    172 		incr = e_atof(argv[1]);
    173 		prec = get_precision(argv[1], prec);
    174 		/* Plan 9/GNU don't do zero */
    175 		if (incr == 0.0)
    176 			errx(1, "zero %screment", (first < last)? "in" : "de");
    177 	}
    178 
    179 	/* default is one for Plan 9/GNU work alike */
    180 	if (incr == 0.0)
    181 		incr = (first < last) ? 1.0 : -1.0;
    182 
    183 	if (incr <= 0.0 && first < last)
    184 		errx(1, "needs positive increment");
    185 
    186 	if (incr >= 0.0 && first > last)
    187 		errx(1, "needs negative decrement");
    188 
    189 	if (fmt != NULL) {
    190 		if (!valid_format(fmt))
    191 			errx(1, "invalid format string: `%s'", fmt);
    192 		fmt = unescape(fmt);
    193 		if (!valid_format(fmt))
    194 			errx(1, "invalid format string");
    195 		/*
    196 	         * XXX to be bug for bug compatible with Plan 9 add a
    197 		 * newline if none found at the end of the format string.
    198 		 */
    199 	} else {
    200 		if (prec == 0)
    201 			fmt = default_format;
    202 		else {
    203 			sprintf(buf, default_format_fmt, prec);
    204 			fmt = buf;
    205 		}
    206 		fmt = generate_format(first, incr, last, equalize, pad, fmt);
    207 	}
    208 
    209 	if (incr > 0) {
    210 		printf(fmt, first);
    211 		for (first += incr; first <= last; first += incr) {
    212 			fputs(sep, stdout);
    213 			printf(fmt, first);
    214 		}
    215 	} else {
    216 		printf(fmt, first);
    217 		for (first += incr; first >= last; first += incr) {
    218 			fputs(sep, stdout);
    219 			printf(fmt, first);
    220 		}
    221 	}
    222 	if (term != NULL)
    223 		fputs(term, stdout);
    224 
    225 	return (0);
    226 }
    227 
    228 /*
    229  * numeric - verify that string is numeric
    230  */
    231 int
    232 numeric(const char *s)
    233 {
    234 	int seen_decimal_pt, decimal_pt_len;
    235 
    236 	/* skip any sign */
    237 	if (ISSIGN((unsigned char)*s))
    238 		s++;
    239 
    240 	seen_decimal_pt = 0;
    241 	decimal_pt_len = strlen(decimal_point);
    242 	while (*s) {
    243 		if (!isdigit((unsigned char)*s)) {
    244 			if (!seen_decimal_pt &&
    245 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
    246 				s += decimal_pt_len;
    247 				seen_decimal_pt = 1;
    248 				continue;
    249 			}
    250 			if (ISEXP((unsigned char)*s)) {
    251 				s++;
    252 				/* optional sign */
    253 				if (ISSIGN((unsigned char)*s))
    254 					s++;
    255 				continue;
    256 			}
    257 			break;
    258 		}
    259 		s++;
    260 	}
    261 	return (*s == '\0');
    262 }
    263 
    264 /*
    265  * valid_format - validate user specified format string
    266  */
    267 int
    268 valid_format(const char *fmt)
    269 {
    270 	unsigned conversions = 0;
    271 
    272 	while (*fmt != '\0') {
    273 		/* scan for conversions */
    274 		if (*fmt != '%') {
    275 			fmt++;
    276 			continue;
    277 		}
    278 		fmt++;
    279 
    280 		/* allow %% but not things like %10% */
    281 		if (*fmt == '%') {
    282 			fmt++;
    283 			continue;
    284 		}
    285 
    286 		/* flags */
    287 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
    288 			fmt++;
    289 		}
    290 
    291 		/* field width */
    292 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    293 			fmt++;
    294 		}
    295 
    296 		/* precision */
    297 		if (*fmt == '.') {
    298 			fmt++;
    299 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    300 				fmt++;
    301 			}
    302 		}
    303 
    304 		/* conversion */
    305 		switch (*fmt) {
    306 		    case 'A':
    307 		    case 'a':
    308 		    case 'E':
    309 		    case 'e':
    310 		    case 'F':
    311 		    case 'f':
    312 		    case 'G':
    313 		    case 'g':
    314 			/* floating point formats are accepted */
    315 			conversions++;
    316 			break;
    317 		    default:
    318 			/* anything else is not */
    319 			return 0;
    320 		}
    321 	}
    322 
    323 	return (conversions <= 1);
    324 }
    325 
    326 /*
    327  * unescape - handle C escapes in a string
    328  */
    329 char *
    330 unescape(char *orig)
    331 {
    332 	char c, *cp, *new = orig;
    333 	int i;
    334 
    335 	for (cp = orig; (*orig = *cp); cp++, orig++) {
    336 		if (*cp != '\\')
    337 			continue;
    338 
    339 		switch (*++cp) {
    340 		case 'a':	/* alert (bell) */
    341 			*orig = '\a';
    342 			continue;
    343 		case 'b':	/* backspace */
    344 			*orig = '\b';
    345 			continue;
    346 		case 'e':	/* escape */
    347 			*orig = '\x1B';
    348 			continue;
    349 		case 'f':	/* formfeed */
    350 			*orig = '\f';
    351 			continue;
    352 		case 'n':	/* newline */
    353 			*orig = '\n';
    354 			continue;
    355 		case 'r':	/* carriage return */
    356 			*orig = '\r';
    357 			continue;
    358 		case 't':	/* horizontal tab */
    359 			*orig = '\t';
    360 			continue;
    361 		case 'v':	/* vertical tab */
    362 			*orig = '\v';
    363 			continue;
    364 		case '\\':	/* backslash */
    365 			*orig = '\\';
    366 			continue;
    367 		case '\'':	/* single quote */
    368 			*orig = '\'';
    369 			continue;
    370 		case '\"':	/* double quote */
    371 			*orig = '"';
    372 			continue;
    373 		case '0':
    374 		case '1':
    375 		case '2':
    376 		case '3':	/* octal */
    377 		case '4':
    378 		case '5':
    379 		case '6':
    380 		case '7':	/* number */
    381 			for (i = 0, c = 0;
    382 			     ISODIGIT((unsigned char)*cp) && i < 3;
    383 			     i++, cp++) {
    384 				c <<= 3;
    385 				c |= (*cp - '0');
    386 			}
    387 			*orig = c;
    388 			--cp;
    389 			continue;
    390 		case 'x':	/* hexadecimal number */
    391 			cp++;	/* skip 'x' */
    392 			for (i = 0, c = 0;
    393 			     isxdigit((unsigned char)*cp) && i < 2;
    394 			     i++, cp++) {
    395 				c <<= 4;
    396 				if (isdigit((unsigned char)*cp))
    397 					c |= (*cp - '0');
    398 				else
    399 					c |= ((toupper((unsigned char)*cp) -
    400 					    'A') + 10);
    401 			}
    402 			*orig = c;
    403 			--cp;
    404 			continue;
    405 		default:
    406 			--cp;
    407 			break;
    408 		}
    409 	}
    410 
    411 	return (new);
    412 }
    413 
    414 /*
    415  * e_atof - convert an ASCII string to a double
    416  *	exit if string is not a valid double, or if converted value would
    417  *	cause overflow or underflow
    418  */
    419 double
    420 e_atof(const char *num)
    421 {
    422 	char *endp;
    423 	double dbl;
    424 
    425 	errno = 0;
    426 	dbl = strtod(num, &endp);
    427 
    428 	if (errno == ERANGE)
    429 		/* under or overflow */
    430 		err(2, "%s", num);
    431 	else if (*endp != '\0')
    432 		/* "junk" left in number */
    433 		errx(2, "invalid floating point argument: %s", num);
    434 
    435 	/* zero shall have no sign */
    436 	if (dbl == -0.0)
    437 		dbl = 0;
    438 	return (dbl);
    439 }
    440 
    441 /*
    442  * decimal_places - count decimal places in a number (string)
    443  */
    444 int
    445 decimal_places(const char *number)
    446 {
    447 	int places = 0;
    448 	char *dp;
    449 
    450 	/* look for a decimal point */
    451 	if ((dp = strstr(number, decimal_point))) {
    452 		dp += strlen(decimal_point);
    453 
    454 		while (isdigit((unsigned char)*dp++))
    455 			places++;
    456 	}
    457 	return (places);
    458 }
    459 
    460 /*
    461  * generate_format - create a format string
    462  *
    463  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
    464  * when "%g" prints as "%e" (this way no width adjustments are made)
    465  */
    466 char *
    467 generate_format(double first, double incr, double last,
    468     int equalize, char pad, char *deffmt)
    469 {
    470 	static char buf[256];
    471 	char cc = '\0';
    472 	int precision, width1, width2, places;
    473 
    474 	if (equalize == 0)
    475 		return deffmt;
    476 
    477 	/* figure out "last" value printed */
    478 	if (first > last)
    479 		last = first - incr * floor((first - last) / incr);
    480 	else
    481 		last = first + incr * floor((last - first) / incr);
    482 
    483 	sprintf(buf, deffmt, incr);
    484 	if (strchr(buf, 'e'))
    485 		cc = 'e';
    486 	precision = decimal_places(buf);
    487 
    488 	width1 = sprintf(buf, deffmt, first);
    489 	if (strchr(buf, 'e'))
    490 		cc = 'e';
    491 	if ((places = decimal_places(buf)))
    492 		width1 -= (places + strlen(decimal_point));
    493 
    494 	precision = MAX(places, precision);
    495 
    496 	width2 = sprintf(buf, deffmt, last);
    497 	if (strchr(buf, 'e'))
    498 		cc = 'e';
    499 	if ((places = decimal_places(buf)))
    500 		width2 -= (places + strlen(decimal_point));
    501 
    502 	if (precision) {
    503 		sprintf(buf, "%%%c%d.%d%c", pad,
    504 		    MAX(width1, width2) + (int) strlen(decimal_point) +
    505 		    precision, precision, (cc) ? cc : 'f');
    506 	} else {
    507 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
    508 		    (cc) ? cc : 'g');
    509 	}
    510 
    511 	return (buf);
    512 }
    513