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seq.c revision 1.3 
      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  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgment:
     18  *      This product includes software developed by the NetBSD
     19  *      Foundation, Inc. and its contributors.
     20  * 4. Neither the name of The NetBSD Foundation nor the names of its
     21  *    contributors may be used to endorse or promote products derived
     22  *    from this software without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     25  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     27  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     28  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     34  * POSSIBILITY OF SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #ifndef lint
     39 __COPYRIGHT("@(#) Copyright (c) 2005\n\
     40 	The NetBSD Foundation, Inc.  All rights reserved.\n");
     41 __RCSID("$NetBSD: seq.c,v 1.3 2008/01/18 16:16:10 ginsbach Exp $");
     42 #endif /* not lint */
     43 
     44 #include <ctype.h>
     45 #include <err.h>
     46 #include <errno.h>
     47 #include <math.h>
     48 #include <locale.h>
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <string.h>
     52 #include <unistd.h>
     53 
     54 #define ZERO	'0'
     55 #define SPACE	' '
     56 
     57 #define MAX(a, b)	(((a) < (b))? (b) : (a))
     58 #define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
     59 #define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
     60 #define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
     61 
     62 /* Globals */
     63 
     64 const char *decimal_point = ".";	/* default */
     65 char default_format[] = { "%g" };	/* default */
     66 
     67 /* Prototypes */
     68 
     69 double e_atof(const char *);
     70 
     71 int decimal_places(const char *);
     72 int main(int, char *[]);
     73 int numeric(const char *);
     74 int valid_format(const char *);
     75 
     76 char *generate_format(double, double, double, int, char);
     77 char *unescape(char *);
     78 
     79 /*
     80  * The seq command will print out a numeric sequence from 1, the default,
     81  * to a user specified upper limit by 1.  The lower bound and increment
     82  * maybe indicated by the user on the command line.  The sequence can
     83  * be either whole, the default, or decimal numbers.
     84  */
     85 int
     86 main(int argc, char *argv[])
     87 {
     88 	int c = 0, errflg = 0;
     89 	int equalize = 0;
     90 	double first = 1.0;
     91 	double last = 0.0;
     92 	double incr = 0.0;
     93 	struct lconv *locale;
     94 	char *fmt = NULL;
     95 	const char *sep = "\n";
     96 	const char *term = NULL;
     97 	char pad = ZERO;
     98 
     99 	/* Determine the locale's decimal point. */
    100 	locale = localeconv();
    101 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
    102 		decimal_point = locale->decimal_point;
    103 
    104 	/*
    105          * Process options, but handle negative numbers separately
    106          * least they trip up getopt(3).
    107          */
    108 	while ((optind < argc) && !numeric(argv[optind]) &&
    109 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
    110 
    111 		switch (c) {
    112 		case 'f':	/* format (plan9) */
    113 			fmt = optarg;
    114 			equalize = 0;
    115 			break;
    116 		case 's':	/* separator (GNU) */
    117 			sep = unescape(optarg);
    118 			break;
    119 		case 't':	/* terminator (new) */
    120 			term = unescape(optarg);
    121 			break;
    122 		case 'w':	/* equal width (plan9) */
    123 			if (!fmt)
    124 				if (equalize++)
    125 					pad = SPACE;
    126 			break;
    127 		case 'h':	/* help (GNU) */
    128 		default:
    129 			errflg++;
    130 			break;
    131 		}
    132 	}
    133 
    134 	argc -= optind;
    135 	argv += optind;
    136 	if (argc < 1 || argc > 3)
    137 		errflg++;
    138 
    139 	if (errflg) {
    140 		fprintf(stderr,
    141 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
    142 		    getprogname());
    143 		exit(1);
    144 	}
    145 
    146 	last = e_atof(argv[argc - 1]);
    147 
    148 	if (argc > 1)
    149 		first = e_atof(argv[0]);
    150 
    151 	if (argc > 2) {
    152 		incr = e_atof(argv[1]);
    153 		/* Plan 9/GNU don't do zero */
    154 		if (incr == 0.0)
    155 			errx(1, "zero %screment", (first < last)? "in" : "de");
    156 	}
    157 
    158 	/* default is one for Plan 9/GNU work alike */
    159 	if (incr == 0.0)
    160 		incr = (first < last) ? 1.0 : -1.0;
    161 
    162 	if (incr <= 0.0 && first < last)
    163 		errx(1, "needs positive increment");
    164 
    165 	if (incr >= 0.0 && first > last)
    166 		errx(1, "needs negative decrement");
    167 
    168 	if (fmt != NULL) {
    169 		if (!valid_format(fmt))
    170 			errx(1, "invalid format string: `%s'", fmt);
    171 		fmt = unescape(fmt);
    172 		/*
    173 	         * XXX to be bug for bug compatible with Plan 9 add a
    174 		 * newline if none found at the end of the format string.
    175 		 */
    176 	} else
    177 		fmt = generate_format(first, incr, last, equalize, pad);
    178 
    179 	if (incr > 0) {
    180 		for (; first <= last; first += incr) {
    181 			printf(fmt, first);
    182 			fputs(sep, stdout);
    183 		}
    184 	} else {
    185 		for (; first >= last; first += incr) {
    186 			printf(fmt, first);
    187 			fputs(sep, stdout);
    188 		}
    189 	}
    190 	if (term != NULL)
    191 		fputs(term, stdout);
    192 
    193 	return (0);
    194 }
    195 
    196 /*
    197  * numeric - verify that string is numeric
    198  */
    199 int
    200 numeric(const char *s)
    201 {
    202 	int seen_decimal_pt, decimal_pt_len;
    203 
    204 	/* skip any sign */
    205 	if (ISSIGN((unsigned char)*s))
    206 		s++;
    207 
    208 	seen_decimal_pt = 0;
    209 	decimal_pt_len = strlen(decimal_point);
    210 	while (*s) {
    211 		if (!isdigit((unsigned char)*s)) {
    212 			if (!seen_decimal_pt &&
    213 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
    214 				s += decimal_pt_len;
    215 				seen_decimal_pt = 1;
    216 				continue;
    217 			}
    218 			if (ISEXP((unsigned char)*s)) {
    219 				s++;
    220 				if (ISSIGN((unsigned char)*s)) {
    221 					s++;
    222 					continue;
    223 				}
    224 			}
    225 			break;
    226 		}
    227 		s++;
    228 	}
    229 	return (*s == '\0');
    230 }
    231 
    232 /*
    233  * valid_format - validate user specified format string
    234  */
    235 int
    236 valid_format(const char *fmt)
    237 {
    238 	int conversions = 0;
    239 
    240 	while (*fmt != '\0') {
    241 		/* scan for conversions */
    242 		if (*fmt != '\0' && *fmt != '%') {
    243 			do {
    244 				fmt++;
    245 			} while (*fmt != '\0' && *fmt != '%');
    246 		}
    247 		/* scan a conversion */
    248 		if (*fmt != '\0') {
    249 			do {
    250 				fmt++;
    251 
    252 				/* ok %% */
    253 				if (*fmt == '%') {
    254 					fmt++;
    255 					break;
    256 				}
    257 				/* valid conversions */
    258 				if (strchr("eEfgG", *fmt) &&
    259 				    conversions++ < 1) {
    260 					fmt++;
    261 					break;
    262 				}
    263 				/* flags, width and precsision */
    264 				if (isdigit((unsigned char)*fmt) ||
    265 				    strchr("+- 0#.", *fmt))
    266 					continue;
    267 
    268 				/* oops! bad conversion format! */
    269 				return (0);
    270 			} while (*fmt != '\0');
    271 		}
    272 	}
    273 
    274 	return (conversions <= 1);
    275 }
    276 
    277 /*
    278  * unescape - handle C escapes in a string
    279  */
    280 char *
    281 unescape(char *orig)
    282 {
    283 	char c, *cp, *new = orig;
    284 	int i;
    285 
    286 	for (cp = orig; (*orig = *cp); cp++, orig++) {
    287 		if (*cp != '\\')
    288 			continue;
    289 
    290 		switch (*++cp) {
    291 		case 'a':	/* alert (bell) */
    292 			*orig = '\a';
    293 			continue;
    294 		case 'b':	/* backspace */
    295 			*orig = '\b';
    296 			continue;
    297 		case 'e':	/* escape */
    298 			*orig = '\e';
    299 			continue;
    300 		case 'f':	/* formfeed */
    301 			*orig = '\f';
    302 			continue;
    303 		case 'n':	/* newline */
    304 			*orig = '\n';
    305 			continue;
    306 		case 'r':	/* carriage return */
    307 			*orig = '\r';
    308 			continue;
    309 		case 't':	/* horizontal tab */
    310 			*orig = '\t';
    311 			continue;
    312 		case 'v':	/* vertical tab */
    313 			*orig = '\v';
    314 			continue;
    315 		case '\\':	/* backslash */
    316 			*orig = '\\';
    317 			continue;
    318 		case '\'':	/* single quote */
    319 			*orig = '\'';
    320 			continue;
    321 		case '\"':	/* double quote */
    322 			*orig = '"';
    323 			continue;
    324 		case '0':
    325 		case '1':
    326 		case '2':
    327 		case '3':	/* octal */
    328 		case '4':
    329 		case '5':
    330 		case '6':
    331 		case '7':	/* number */
    332 			for (i = 0, c = 0;
    333 			     ISODIGIT((unsigned char)*cp) && i < 3;
    334 			     i++, cp++) {
    335 				c <<= 3;
    336 				c |= (*cp - '0');
    337 			}
    338 			*orig = c;
    339 			--cp;
    340 			continue;
    341 		case 'x':	/* hexidecimal number */
    342 			cp++;	/* skip 'x' */
    343 			for (i = 0, c = 0;
    344 			     isxdigit((unsigned char)*cp) && i < 2;
    345 			     i++, cp++) {
    346 				c <<= 4;
    347 				if (isdigit((unsigned char)*cp))
    348 					c |= (*cp - '0');
    349 				else
    350 					c |= ((toupper((unsigned char)*cp) -
    351 					    'A') + 10);
    352 			}
    353 			*orig = c;
    354 			--cp;
    355 			continue;
    356 		default:
    357 			--cp;
    358 			break;
    359 		}
    360 	}
    361 
    362 	return (new);
    363 }
    364 
    365 /*
    366  * e_atof - convert an ASCII string to a double
    367  *	exit if string is not a valid double, or if converted value would
    368  *	cause overflow or underflow
    369  */
    370 double
    371 e_atof(const char *num)
    372 {
    373 	char *endp;
    374 	double dbl;
    375 
    376 	errno = 0;
    377 	dbl = strtod(num, &endp);
    378 
    379 	if (errno == ERANGE)
    380 		/* under or overflow */
    381 		err(2, "%s", num);
    382 	else if (*endp != '\0')
    383 		/* "junk" left in number */
    384 		errx(2, "invalid floating point argument: %s", num);
    385 
    386 	/* zero shall have no sign */
    387 	if (dbl == -0.0)
    388 		dbl = 0;
    389 	return (dbl);
    390 }
    391 
    392 /*
    393  * decimal_places - count decimal places in a number (string)
    394  */
    395 int
    396 decimal_places(const char *number)
    397 {
    398 	int places = 0;
    399 	char *dp;
    400 
    401 	/* look for a decimal point */
    402 	if ((dp = strstr(number, decimal_point))) {
    403 		dp += strlen(decimal_point);
    404 
    405 		while (isdigit((unsigned char)*dp++))
    406 			places++;
    407 	}
    408 	return (places);
    409 }
    410 
    411 /*
    412  * generate_format - create a format string
    413  *
    414  * XXX to be bug for bug compatable with Plan9 and GNU return "%g"
    415  * when "%g" prints as "%e" (this way no width adjustments are made)
    416  */
    417 char *
    418 generate_format(double first, double incr, double last, int equalize, char pad)
    419 {
    420 	static char buf[256];
    421 	char cc = '\0';
    422 	int precision, width1, width2, places;
    423 
    424 	if (equalize == 0)
    425 		return (default_format);
    426 
    427 	/* figure out "last" value printed */
    428 	if (first > last)
    429 		last = first - incr * floor((first - last) / incr);
    430 	else
    431 		last = first + incr * floor((last - first) / incr);
    432 
    433 	sprintf(buf, "%g", incr);
    434 	if (strchr(buf, 'e'))
    435 		cc = 'e';
    436 	precision = decimal_places(buf);
    437 
    438 	width1 = sprintf(buf, "%g", first);
    439 	if (strchr(buf, 'e'))
    440 		cc = 'e';
    441 	if ((places = decimal_places(buf)))
    442 		width1 -= (places + strlen(decimal_point));
    443 
    444 	precision = MAX(places, precision);
    445 
    446 	width2 = sprintf(buf, "%g", last);
    447 	if (strchr(buf, 'e'))
    448 		cc = 'e';
    449 	if ((places = decimal_places(buf)))
    450 		width2 -= (places + strlen(decimal_point));
    451 
    452 	if (precision) {
    453 		sprintf(buf, "%%%c%d.%d%c", pad,
    454 		    MAX(width1, width2) + (int) strlen(decimal_point) +
    455 		    precision, precision, (cc) ? cc : 'f');
    456 	} else {
    457 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
    458 		    (cc) ? cc : 'g');
    459 	}
    460 
    461 	return (buf);
    462 }
    463