1 /* $OpenBSD: seq.c,v 1.7 2023/06/12 20:15:06 millert Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Brian Ginsbach. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <ctype.h> 33 #include <err.h> 34 #include <errno.h> 35 #include <getopt.h> 36 #include <math.h> 37 #include <locale.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #define VERSION "1.0" 44 #define ZERO '0' 45 #define SPACE ' ' 46 47 #define MAXIMUM(a, b) (((a) < (b))? (b) : (a)) 48 #define ISSIGN(c) ((int)(c) == '-' || (int)(c) == '+') 49 #define ISEXP(c) ((int)(c) == 'e' || (int)(c) == 'E') 50 #define ISODIGIT(c) ((int)(c) >= '0' && (int)(c) <= '7') 51 52 /* Globals */ 53 54 static const char *decimal_point = "."; /* default */ 55 static char default_format[] = { "%g" }; /* default */ 56 57 static const struct option long_opts[] = { 58 {"format", required_argument, NULL, 'f'}, 59 {"help", no_argument, NULL, 'h'}, 60 {"separator", required_argument, NULL, 's'}, 61 {"version", no_argument, NULL, 'v'}, 62 {"equal-width", no_argument, NULL, 'w'}, 63 {NULL, no_argument, NULL, 0} 64 }; 65 66 /* Prototypes */ 67 68 static double e_atof(const char *); 69 70 static int decimal_places(const char *); 71 static int numeric(const char *); 72 static int valid_format(const char *); 73 74 static char *generate_format(double, double, double, int, char); 75 76 static __dead void usage(int error); 77 78 /* 79 * The seq command will print out a numeric sequence from 1, the default, 80 * to a user specified upper limit by 1. The lower bound and increment 81 * maybe indicated by the user on the command line. The sequence can 82 * be either whole, the default, or decimal numbers. 83 */ 84 int 85 main(int argc, char *argv[]) 86 { 87 int c = 0; 88 int equalize = 0; 89 double first = 1.0; 90 double last = 0.0; 91 double incr = 0.0; 92 double prev = 0.0; 93 double cur, step; 94 struct lconv *locale; 95 char *fmt = NULL; 96 const char *sep = "\n"; 97 const char *term = "\n"; 98 char *cur_print, *last_print, *prev_print; 99 char pad = ZERO; 100 101 if (pledge("stdio", NULL) == -1) 102 err(1, "pledge"); 103 104 /* Determine the locale's decimal point. */ 105 locale = localeconv(); 106 if (locale && locale->decimal_point && locale->decimal_point[0] != '\0') 107 decimal_point = locale->decimal_point; 108 109 /* 110 * Process options, but handle negative numbers separately 111 * least they trip up getopt(3). 112 */ 113 while ((optind < argc) && !numeric(argv[optind]) && 114 (c = getopt_long(argc, argv, "+f:s:w", long_opts, NULL)) != -1) { 115 116 switch (c) { 117 case 'f': /* format (plan9/GNU) */ 118 fmt = optarg; 119 equalize = 0; 120 break; 121 case 's': /* separator (GNU) */ 122 sep = optarg; 123 break; 124 case 'v': /* version (GNU) */ 125 printf("seq version %s\n", VERSION); 126 return 0; 127 case 'w': /* equal width (plan9/GNU) */ 128 if (fmt == NULL) { 129 if (equalize++) 130 pad = SPACE; 131 } 132 break; 133 case 'h': /* help (GNU) */ 134 usage(0); 135 break; 136 default: 137 usage(1); 138 break; 139 } 140 } 141 142 argc -= optind; 143 argv += optind; 144 if (argc < 1 || argc > 3) 145 usage(1); 146 147 last = e_atof(argv[argc - 1]); 148 149 if (argc > 1) 150 first = e_atof(argv[0]); 151 152 if (argc > 2) { 153 incr = e_atof(argv[1]); 154 /* Plan 9/GNU don't do zero */ 155 if (incr == 0.0) 156 errx(1, "zero %screment", (first < last) ? "in" : "de"); 157 } 158 159 /* default is one for Plan 9/GNU work alike */ 160 if (incr == 0.0) 161 incr = (first < last) ? 1.0 : -1.0; 162 163 if (incr <= 0.0 && first < last) 164 errx(1, "needs positive increment"); 165 166 if (incr >= 0.0 && first > last) 167 errx(1, "needs negative decrement"); 168 169 if (fmt != NULL) { 170 if (!valid_format(fmt)) 171 errx(1, "invalid format string: `%s'", 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 warnx("first: %f, incr: %f", first, incr); 180 for (step = 1, cur = first; incr > 0 ? cur <= last : cur >= last; 181 cur = first + incr * step++) { 182 if (cur != first) 183 fputs(sep, stdout); 184 printf(fmt, cur); 185 prev = cur; 186 } 187 188 /* 189 * Did we miss the last value of the range in the loop above? 190 * 191 * We might have, so check if the printable version of the last 192 * computed value ('cur') and desired 'last' value are equal. If 193 * they are equal after formatting truncation, but 'cur' and 'prev' 194 * are different, it means the exit condition of the loop held true 195 * due to a rounding error and we still need to print 'last'. 196 */ 197 if (asprintf(&cur_print, fmt, cur) == -1 || 198 asprintf(&last_print, fmt, last) == -1 || 199 asprintf(&prev_print, fmt, prev) == -1) 200 err(1, "asprintf"); 201 if (strcmp(cur_print, last_print) == 0 && 202 strcmp(cur_print, prev_print) != 0) { 203 if (cur != first) 204 fputs(sep, stdout); 205 fputs(last_print, stdout); 206 } 207 free(cur_print); 208 free(last_print); 209 free(prev_print); 210 211 fputs(term, stdout); 212 213 return 0; 214 } 215 216 /* 217 * numeric - verify that string is numeric 218 */ 219 static int 220 numeric(const char *s) 221 { 222 int seen_decimal_pt, decimal_pt_len; 223 224 /* skip any sign */ 225 if (ISSIGN((unsigned char)*s)) 226 s++; 227 228 seen_decimal_pt = 0; 229 decimal_pt_len = strlen(decimal_point); 230 while (*s) { 231 if (!isdigit((unsigned char)*s)) { 232 if (!seen_decimal_pt && 233 strncmp(s, decimal_point, decimal_pt_len) == 0) { 234 s += decimal_pt_len; 235 seen_decimal_pt = 1; 236 continue; 237 } 238 if (ISEXP((unsigned char)*s)) { 239 s++; 240 if (ISSIGN((unsigned char)*s) || 241 isdigit((unsigned char)*s)) { 242 s++; 243 continue; 244 } 245 } 246 break; 247 } 248 s++; 249 } 250 return *s == '\0'; 251 } 252 253 /* 254 * valid_format - validate user specified format string 255 */ 256 static int 257 valid_format(const char *fmt) 258 { 259 unsigned conversions = 0; 260 261 while (*fmt != '\0') { 262 /* scan for conversions */ 263 if (*fmt != '%') { 264 fmt++; 265 continue; 266 } 267 fmt++; 268 269 /* allow %% but not things like %10% */ 270 if (*fmt == '%') { 271 fmt++; 272 continue; 273 } 274 275 /* flags */ 276 while (*fmt != '\0' && strchr("#0- +'", *fmt)) { 277 fmt++; 278 } 279 280 /* field width */ 281 while (*fmt != '\0' && strchr("0123456789", *fmt)) { 282 fmt++; 283 } 284 285 /* precision */ 286 if (*fmt == '.') { 287 fmt++; 288 while (*fmt != '\0' && strchr("0123456789", *fmt)) { 289 fmt++; 290 } 291 } 292 293 /* conversion */ 294 switch (*fmt) { 295 case 'A': 296 case 'a': 297 case 'E': 298 case 'e': 299 case 'F': 300 case 'f': 301 case 'G': 302 case 'g': 303 /* floating point formats are accepted */ 304 conversions++; 305 break; 306 default: 307 /* anything else is not */ 308 return 0; 309 } 310 } 311 312 /* PR 236347 -- user format strings must have a conversion */ 313 return conversions == 1; 314 } 315 316 /* 317 * e_atof - convert an ASCII string to a double 318 * exit if string is not a valid double, or if converted value would 319 * cause overflow or underflow 320 */ 321 static double 322 e_atof(const char *num) 323 { 324 char *endp; 325 double dbl; 326 327 errno = 0; 328 dbl = strtod(num, &endp); 329 330 if (errno == ERANGE) 331 /* under or overflow */ 332 err(2, "%s", num); 333 else if (*endp != '\0') 334 /* "junk" left in number */ 335 errx(2, "invalid floating point argument: %s", num); 336 337 /* zero shall have no sign */ 338 if (dbl == -0.0) 339 dbl = 0; 340 return dbl; 341 } 342 343 /* 344 * decimal_places - count decimal places in a number (string) 345 */ 346 static int 347 decimal_places(const char *number) 348 { 349 int places = 0; 350 char *dp; 351 352 /* look for a decimal point */ 353 if ((dp = strstr(number, decimal_point))) { 354 dp += strlen(decimal_point); 355 356 while (isdigit((unsigned char)*dp++)) 357 places++; 358 } 359 return places; 360 } 361 362 /* 363 * generate_format - create a format string 364 * 365 * XXX to be bug for bug compatible with Plan9 and GNU return "%g" 366 * when "%g" prints as "%e" (this way no width adjustments are made) 367 */ 368 static char * 369 generate_format(double first, double incr, double last, int equalize, char pad) 370 { 371 static char buf[256]; 372 char cc = '\0'; 373 int precision, width1, width2, places; 374 375 if (equalize == 0) 376 return default_format; 377 378 /* figure out "last" value printed */ 379 if (first > last) 380 last = first - incr * floor((first - last) / incr); 381 else 382 last = first + incr * floor((last - first) / incr); 383 384 snprintf(buf, sizeof(buf), "%g", incr); 385 if (strchr(buf, 'e')) 386 cc = 'e'; 387 precision = decimal_places(buf); 388 389 width1 = snprintf(buf, sizeof(buf), "%g", first); 390 if (strchr(buf, 'e')) 391 cc = 'e'; 392 if ((places = decimal_places(buf))) 393 width1 -= (places + strlen(decimal_point)); 394 395 precision = MAXIMUM(places, precision); 396 397 width2 = snprintf(buf, sizeof(buf), "%g", last); 398 if (strchr(buf, 'e')) 399 cc = 'e'; 400 if ((places = decimal_places(buf))) 401 width2 -= (places + strlen(decimal_point)); 402 403 /* XXX if incr is floating point fix the precision */ 404 if (precision) { 405 snprintf(buf, sizeof(buf), "%%%c%d.%d%c", pad, 406 MAXIMUM(width1, width2) + (int)strlen(decimal_point) + 407 precision, precision, (cc) ? cc : 'f'); 408 } else { 409 snprintf(buf, sizeof(buf), "%%%c%d%c", pad, 410 MAXIMUM(width1, width2), (cc) ? cc : 'g'); 411 } 412 413 return buf; 414 } 415 416 static __dead void 417 usage(int error) 418 { 419 fprintf(stderr, 420 "usage: %s [-w] [-f format] [-s string] [first [incr]] last\n", 421 getprogname()); 422 exit(error); 423 } 424