src/seq.c

   1 /* seq - print sequence of numbers to standard output.
   2    Copyright (C) 1994-2002 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Ulrich Drepper.  */
  19
  20 #include <config.h>
  21 #include <getopt.h>
  22 #include <math.h>
  23 #include <stdio.h>
  24 #include <sys/types.h>
  25
  26 #include "system.h"
  27 #include "closeout.h"
  28 #include "error.h"
  29 #include "xstrtol.h"
  30 #include "xstrtod.h"
  31
  32 /* The official name of this program (e.g., no `g' prefix).  */
  33 #define PROGRAM_NAME "seq"
  34
  35 #define AUTHORS "Ulrich Drepper"
  36
  37 /* If nonzero print all number with equal width.  */
  38 static int equal_width;
  39
  40 /* The name that this program was run with.  */
  41 char *program_name;
  42
  43 /* The string used to separate two numbers.  */
  44 static char *separator;
  45
  46 /* The string output after all numbers have been output.
  47    Usually "\n" or "\0".  */
  48 /* FIXME: make this an option.  */
  49 static char *terminator = "\n";
  50
  51 /* The representation of the decimal point in the current locale.
  52    Always "." if the localeconv function is not supported.  */
  53 static char *decimal_point = ".";
  54
  55 /* The starting number.  */
  56 static double first;
  57
  58 /* The increment.  */
  59 static double step;
  60
  61 /* The last number.  */
  62 static double last;
  63
  64 static struct option const long_options[] =
  65 {
  66   { "equal-width", no_argument, NULL, 'w'},
  67   { "format", required_argument, NULL, 'f'},
  68   { "separator", required_argument, NULL, 's'},
  69   {GETOPT_HELP_OPTION_DECL},
  70   {GETOPT_VERSION_OPTION_DECL},
  71   { NULL, 0, NULL, 0}
  72 };
  73
  74 void
  75 usage (int status)
  76 {
  77   if (status != 0)
  78     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  79              program_name);
  80   else
  81     {
  82       printf (_("\
  83 Usage: %s [OPTION]... LAST\n\
  84   or:  %s [OPTION]... FIRST LAST\n\
  85   or:  %s [OPTION]... FIRST INCREMENT LAST\n\
  86 "), program_name, program_name, program_name);
  87       fputs (_("\
  88 Print numbers from FIRST to LAST, in steps of INCREMENT.\n\
  89 \n\
  90   -f, --format=FORMAT      use printf style floating-point FORMAT (default: %g)\n\
  91   -s, --separator=STRING   use STRING to separate numbers (default: \\n)\n\
  92   -w, --equal-width        equalize width by padding with leading zeroes\n\
  93 "), stdout);
  94       fputs (HELP_OPTION_DESCRIPTION, stdout);
  95       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  96       fputs (_("\
  97 \n\
  98 If FIRST or INCREMENT is omitted, it defaults to 1.\n\
  99 FIRST, INCREMENT, and LAST are interpreted as floating point values.\n\
 100 INCREMENT should be positive if FIRST is smaller than LAST, and negative\n\
 101 otherwise.  When given, the FORMAT argument must contain exactly one of\n\
 102 the printf-style, floating point output formats %e, %f, %g\n\
 103 "), stdout);
 104       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 105     }
 106   exit (status);
 107 }
 108
 109 /* Read a double value from the command line.
 110    Return if the string is correct else signal error.  */
 111
 112 static double
 113 scan_double_arg (const char *arg)
 114 {
 115   double ret_val;
 116
 117   if (xstrtod (arg, NULL, &ret_val))
 118     {
 119       error (0, 0, _("invalid floating point argument: %s"), arg);
 120       usage (EXIT_FAILURE);
 121     }
 122
 123   return ret_val;
 124 }
 125
 126 /* Check whether the format string is valid for a single `double'
 127    argument.  Return 0 if not, 1 if correct. */
 128
 129 static int
 130 valid_format (const char *fmt)
 131 {
 132   while (*fmt != '\0')
 133     {
 134       if (*fmt == '%')
 135         {
 136           fmt++;
 137           if (*fmt != '%')
 138             break;
 139         }
 140
 141       fmt++;
 142     }
 143   if (*fmt == '\0')
 144     return 0;
 145
 146   fmt += strspn (fmt, "-+#0");
 147   if (ISDIGIT (*fmt))
 148     {
 149       fmt += strspn (fmt, "0123456789");
 150
 151       if (*fmt == '.')
 152         {
 153           ++fmt;
 154           fmt += strspn (fmt, "0123456789");
 155         }
 156     }
 157
 158   if (!(*fmt == 'e' || *fmt == 'f' || *fmt == 'g'))
 159     return 0;
 160
 161   fmt++;
 162   while (*fmt != '\0')
 163     {
 164       if (*fmt == '%')
 165         {
 166           fmt++;
 167           if (*fmt != '%')
 168             return 0;
 169         }
 170
 171       fmt++;
 172     }
 173
 174   return 1;
 175 }
 176
 177 /* Actually print the sequence of numbers in the specified range, with the
 178    given or default stepping and format.  */
 179 static int
 180 print_numbers (const char *fmt)
 181 {
 182   if (first > last)
 183     {
 184       int i;
 185
 186       if (step >= 0)
 187         {
 188           error (0, 0,
 189                  _("when the starting value is larger than the limit,\n\
 190 the increment must be negative"));
 191           usage (EXIT_FAILURE);
 192         }
 193
 194       printf (fmt, first);
 195       for (i = 1; /* empty */; i++)
 196         {
 197           double x = first + i * step;
 198
 199           if (x < last)
 200             break;
 201
 202           fputs (separator, stdout);
 203           printf (fmt, x);
 204         }
 205     }
 206   else
 207     {
 208       int i;
 209
 210       if (step <= 0)
 211         {
 212           error (0, 0,
 213                  _("when the starting value is smaller than the limit,\n\
 214 the increment must be positive"));
 215           usage (EXIT_FAILURE);
 216         }
 217
 218       printf (fmt, first);
 219       for (i = 1; /* empty */; i++)
 220         {
 221           double x = first + i * step;
 222
 223           if (x > last)
 224             break;
 225
 226           fputs (separator, stdout);
 227           printf (fmt, x);
 228         }
 229     }
 230   fputs (terminator, stdout);
 231
 232   return 0;
 233 }
 234
 235 #if HAVE_RINT && HAVE_MODF && HAVE_FLOOR
 236
 237 /* Return a printf-style format string with which all selected numbers
 238    will format to strings of the same width.  */
 239
 240 static char *
 241 get_width_format ()
 242 {
 243   static char buffer[256];
 244   int full_width;
 245   int frac_width;
 246   int width1, width2;
 247   double max_val;
 248   double min_val;
 249   double temp;
 250
 251   if (first > last)
 252     {
 253       min_val = first - step * floor ((first - last) / step);
 254       max_val = first;
 255     }
 256   else
 257     {
 258       min_val = first;
 259       max_val = first + step * floor ((last - first) / step);
 260     }
 261
 262   sprintf (buffer, "%g", rint (max_val));
 263   if (buffer[strspn (buffer, "0123456789")] != '\0')
 264     return "%g";
 265   width1 = strlen (buffer);
 266
 267   if (min_val < 0.0)
 268     {
 269       double int_min_val = rint (min_val);
 270       sprintf (buffer, "%g", int_min_val);
 271       if (buffer[strspn (buffer, "-0123456789")] != '\0')
 272         return "%g";
 273       /* On some systems, `seq -w -.1 .1 .1' results in buffer being `-0'.
 274          On others, it is just `0'.  The former results in better output.  */
 275       width2 = (int_min_val == 0 ? 2 : strlen (buffer));
 276
 277       width1 = width1 > width2 ? width1 : width2;
 278     }
 279   full_width = width1;
 280
 281   sprintf (buffer, "%g", 1.0 + modf (fabs (min_val), &temp));
 282   width1 = strlen (buffer);
 283   if (width1 == 1)
 284     width1 = 0;
 285   else
 286     {
 287       if (buffer[0] != '1'
 288           /* FIXME: assumes that decimal_point is a single character
 289              string.  */
 290           || buffer[1] != decimal_point[0]
 291           || buffer[2 + strspn (&buffer[2], "0123456789")] != '\0')
 292         return "%g";
 293       width1 -= 2;
 294     }
 295
 296   sprintf (buffer, "%g", 1.0 + modf (fabs (step), &temp));
 297   width2 = strlen (buffer);
 298   if (width2 == 1)
 299     width2 = 0;
 300   else
 301     {
 302       if (buffer[0] != '1'
 303           /* FIXME: assumes that decimal_point is a single character
 304              string.  */
 305           || buffer[1] != decimal_point[0]
 306           || buffer[2 + strspn (&buffer[2], "0123456789")] != '\0')
 307         return "%g";
 308       width2 -= 2;
 309     }
 310   frac_width = width1 > width2 ? width1 : width2;
 311
 312   if (frac_width)
 313     sprintf (buffer, "%%0%d.%df", full_width + 1 + frac_width, frac_width);
 314   else
 315     sprintf (buffer, "%%0%dg", full_width);
 316
 317   return buffer;
 318 }
 319
 320 #else   /* one of the math functions rint, modf, floor is missing.  */
 321
 322 static char *
 323 get_width_format (void)
 324 {
 325   /* We cannot compute the needed information to determine the correct
 326      answer.  So we simply return a value that works for all cases.  */
 327   return "%g";
 328 }
 329
 330 #endif
 331
 332 int
 333 main (int argc, char **argv)
 334 {
 335   int errs;
 336   int optc;
 337   int step_is_set;
 338
 339   /* The printf(3) format used for output.  */
 340   char *format_str = NULL;
 341
 342   program_name = argv[0];
 343   setlocale (LC_ALL, "");
 344   bindtextdomain (PACKAGE, LOCALEDIR);
 345   textdomain (PACKAGE);
 346
 347   atexit (close_stdout);
 348
 349   equal_width = 0;
 350   separator = "\n";
 351   first = 1.0;
 352   step_is_set = 0;
 353
 354   /* Figure out the locale's idea of a decimal point.  */
 355 #if HAVE_LOCALECONV
 356   {
 357     struct lconv *locale;
 358
 359     locale = localeconv ();
 360     /* Paranoia.  */
 361     if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
 362       decimal_point = locale->decimal_point;
 363   }
 364 #endif
 365
 366   /* We have to handle negative numbers in the command line but this
 367      conflicts with the command line arguments.  So explicitly check first
 368      whether the next argument looks like a negative number.  */
 369   while (optind < argc)
 370     {
 371       if (argv[optind][0] == '-'
 372           && ((optc = argv[optind][1]) == decimal_point[0]
 373               || ISDIGIT (optc)))
 374         {
 375           /* means negative number */
 376           break;
 377         }
 378
 379       optc = getopt_long (argc, argv, "+f:s:w", long_options, NULL);
 380       if (optc == -1)
 381         break;
 382
 383       switch (optc)
 384         {
 385         case 0:
 386           break;
 387
 388         case 'f':
 389           format_str = optarg;
 390           break;
 391
 392         case 's':
 393           separator = optarg;
 394           break;
 395
 396         case 'w':
 397           equal_width = 1;
 398           break;
 399
 400         case_GETOPT_HELP_CHAR;
 401
 402         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 403
 404         default:
 405           usage (EXIT_FAILURE);
 406         }
 407     }
 408
 409   if (argc - optind < 1)
 410     {
 411       error (0, 0, _("too few arguments"));
 412       usage (EXIT_FAILURE);
 413     }
 414
 415   if (3 < argc - optind)
 416     {
 417       error (0, 0, _("too many arguments"));
 418       usage (EXIT_FAILURE);
 419     }
 420
 421   if (format_str && !valid_format (format_str))
 422     {
 423       error (0, 0, _("invalid format string: `%s'"), format_str);
 424       usage (EXIT_FAILURE);
 425     }
 426
 427   last = scan_double_arg (argv[optind++]);
 428
 429   if (optind < argc)
 430     {
 431       first = last;
 432       last = scan_double_arg (argv[optind++]);
 433
 434       if (optind < argc)
 435         {
 436           step = last;
 437           step_is_set = 1;
 438           last = scan_double_arg (argv[optind++]);
 439
 440         }
 441     }
 442
 443   if (format_str != NULL && equal_width)
 444     {
 445       error (0, 0, _("\
 446 format string may not be specified when printing equal width strings"));
 447       usage (EXIT_FAILURE);
 448     }
 449
 450   if (!step_is_set)
 451     {
 452       step = first <= last ? 1.0 : -1.0;
 453     }
 454
 455   if (format_str == NULL)
 456     {
 457       if (equal_width)
 458         format_str = get_width_format ();
 459       else
 460         format_str = "%g";
 461     }
 462
 463   errs = print_numbers (format_str);
 464
 465   exit (errs);
 466 }