src/seq.c

   1 /* seq - print sequence of numbers to standard output.
   2    Copyright (C) 1994-2008 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 3 of the License, or
   7    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Ulrich Drepper.  */
  18
  19 #include <config.h>
  20 #include <getopt.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25 #include "c-strtod.h"
  26 #include "error.h"
  27 #include "quote.h"
  28 #include "xstrtod.h"
  29
  30 /* Roll our own isfinite rather than using <math.h>, so that we don't
  31    have to worry about linking -lm just for isfinite.  */
  32 #ifndef isfinite
  33 # define isfinite(x) ((x) * 0 == 0)
  34 #endif
  35
  36 /* The official name of this program (e.g., no `g' prefix).  */
  37 #define PROGRAM_NAME "seq"
  38
  39 #define AUTHORS proper_name ("Ulrich Drepper")
  40
  41 /* If true print all number with equal width.  */
  42 static bool equal_width;
  43
  44 /* The string used to separate two numbers.  */
  45 static char const *separator;
  46
  47 /* The string output after all numbers have been output.
  48    Usually "\n" or "\0".  */
  49 /* FIXME: make this an option.  */
  50 static char const terminator[] = "\n";
  51
  52 static struct option const long_options[] =
  53 {
  54   { "equal-width", no_argument, NULL, 'w'},
  55   { "format", required_argument, NULL, 'f'},
  56   { "separator", required_argument, NULL, 's'},
  57   {GETOPT_HELP_OPTION_DECL},
  58   {GETOPT_VERSION_OPTION_DECL},
  59   { NULL, 0, NULL, 0}
  60 };
  61
  62 void
  63 usage (int status)
  64 {
  65   if (status != EXIT_SUCCESS)
  66     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  67              program_name);
  68   else
  69     {
  70       printf (_("\
  71 Usage: %s [OPTION]... LAST\n\
  72   or:  %s [OPTION]... FIRST LAST\n\
  73   or:  %s [OPTION]... FIRST INCREMENT LAST\n\
  74 "), program_name, program_name, program_name);
  75       fputs (_("\
  76 Print numbers from FIRST to LAST, in steps of INCREMENT.\n\
  77 \n\
  78   -f, --format=FORMAT      use printf style floating-point FORMAT\n\
  79   -s, --separator=STRING   use STRING to separate numbers (default: \\n)\n\
  80   -w, --equal-width        equalize width by padding with leading zeroes\n\
  81 "), stdout);
  82       fputs (HELP_OPTION_DESCRIPTION, stdout);
  83       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  84       fputs (_("\
  85 \n\
  86 If FIRST or INCREMENT is omitted, it defaults to 1.  That is, an\n\
  87 omitted INCREMENT defaults to 1 even when LAST is smaller than FIRST.\n\
  88 FIRST, INCREMENT, and LAST are interpreted as floating point values.\n\
  89 INCREMENT is usually positive if FIRST is smaller than LAST, and\n\
  90 INCREMENT is usually negative if FIRST is greater than LAST.\n\
  91 "), stdout);
  92       fputs (_("\
  93 FORMAT must be suitable for printing one argument of type `double';\n\
  94 it defaults to %.PRECf if FIRST, INCREMENT, and LAST are all fixed point\n\
  95 decimal numbers with maximum precision PREC, and to %g otherwise.\n\
  96 "), stdout);
  97       emit_bug_reporting_address ();
  98     }
  99   exit (status);
 100 }
 101
 102 /* A command-line operand.  */
 103 struct operand
 104 {
 105   /* Its value, converted to 'long double'.  */
 106   long double value;
 107
 108   /* Its print width, if it were printed out in a form similar to its
 109      input form.  An input like "-.1" is treated like "-0.1", and an
 110      input like "1." is treated like "1", but otherwise widths are
 111      left alone.  */
 112   size_t width;
 113
 114   /* Number of digits after the decimal point, or INT_MAX if the
 115      number can't easily be expressed as a fixed-point number.  */
 116   int precision;
 117 };
 118 typedef struct operand operand;
 119
 120 /* Description of what a number-generating format will generate.  */
 121 struct layout
 122 {
 123   /* Number of bytes before and after the number.  */
 124   size_t prefix_len;
 125   size_t suffix_len;
 126 };
 127
 128 /* Read a long double value from the command line.
 129    Return if the string is correct else signal error.  */
 130
 131 static operand
 132 scan_arg (const char *arg)
 133 {
 134   operand ret;
 135
 136   if (! xstrtold (arg, NULL, &ret.value, c_strtold))
 137     {
 138       error (0, 0, _("invalid floating point argument: %s"), arg);
 139       usage (EXIT_FAILURE);
 140     }
 141
 142   /* We don't output spaces or '+' so don't include in width */
 143   while (isspace (to_uchar (*arg)) || *arg == '+')
 144     arg++;
 145
 146   ret.width = strlen (arg);
 147   ret.precision = INT_MAX;
 148
 149   if (! arg[strcspn (arg, "xX")] && isfinite (ret.value))
 150     {
 151       char const *decimal_point = strchr (arg, '.');
 152       if (! decimal_point)
 153         ret.precision = 0;
 154       else
 155         {
 156           size_t fraction_len = strcspn (decimal_point + 1, "eE");
 157           if (fraction_len <= INT_MAX)
 158             ret.precision = fraction_len;
 159           ret.width += (fraction_len == 0                      /* #.  -> #   */
 160                         ? -1
 161                         : (decimal_point == arg                /* .#  -> 0.# */
 162                            || ! ISDIGIT (decimal_point[-1]))); /* -.# -> 0.# */
 163         }
 164       char const *e = strchr (arg, 'e');
 165       if (! e)
 166         e = strchr (arg, 'E');
 167       if (e)
 168         {
 169           long exponent = strtol (e + 1, NULL, 10);
 170           ret.precision += exponent < 0 ? -exponent : 0;
 171         }
 172     }
 173
 174   return ret;
 175 }
 176
 177 /* If FORMAT is a valid printf format for a double argument, return
 178    its long double equivalent, allocated from dynamic storage, and
 179    store into *LAYOUT a description of the output layout; otherwise,
 180    report an error and exit.  */
 181
 182 static char const *
 183 long_double_format (char const *fmt, struct layout *layout)
 184 {
 185   size_t i;
 186   size_t prefix_len = 0;
 187   size_t suffix_len = 0;
 188   size_t length_modifier_offset;
 189   bool has_L;
 190
 191   for (i = 0; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
 192     {
 193       if (!fmt[i])
 194         error (EXIT_FAILURE, 0,
 195                _("format %s has no %% directive"), quote (fmt));
 196       prefix_len++;
 197     }
 198
 199   i++;
 200   i += strspn (fmt + i, "-+#0 '");
 201   i += strspn (fmt + i, "0123456789");
 202   if (fmt[i] == '.')
 203     {
 204       i++;
 205       i += strspn (fmt + i, "0123456789");
 206     }
 207
 208   length_modifier_offset = i;
 209   has_L = (fmt[i] == 'L');
 210   i += has_L;
 211   if (fmt[i] == '\0')
 212     error (EXIT_FAILURE, 0, _("format %s ends in %%"), quote (fmt));
 213   if (! strchr ("efgaEFGA", fmt[i]))
 214     error (EXIT_FAILURE, 0,
 215            _("format %s has unknown %%%c directive"), quote (fmt), fmt[i]);
 216
 217   for (i++; ; i += (fmt[i] == '%') + 1)
 218     if (fmt[i] == '%' && fmt[i + 1] != '%')
 219       error (EXIT_FAILURE, 0, _("format %s has too many %% directives"),
 220              quote (fmt));
 221     else if (fmt[i])
 222       suffix_len++;
 223     else
 224       {
 225         size_t format_size = i + 1;
 226         char *ldfmt = xmalloc (format_size + 1);
 227         memcpy (ldfmt, fmt, length_modifier_offset);
 228         ldfmt[length_modifier_offset] = 'L';
 229         strcpy (ldfmt + length_modifier_offset + 1,
 230                 fmt + length_modifier_offset + has_L);
 231         layout->prefix_len = prefix_len;
 232         layout->suffix_len = suffix_len;
 233         return ldfmt;
 234       }
 235 }
 236
 237 /* Actually print the sequence of numbers in the specified range, with the
 238    given or default stepping and format.  */
 239
 240 static void
 241 print_numbers (char const *fmt, struct layout layout,
 242                long double first, long double step, long double last)
 243 {
 244   bool out_of_range = (step < 0 ? first < last : last < first);
 245
 246   if (! out_of_range)
 247     {
 248       long double x = first;
 249       long double i;
 250
 251       for (i = 1; ; i++)
 252         {
 253           long double x0 = x;
 254           printf (fmt, x);
 255           if (out_of_range)
 256             break;
 257           x = first + i * step;
 258           out_of_range = (step < 0 ? x < last : last < x);
 259
 260           if (out_of_range)
 261             {
 262               /* If the number just past LAST prints as a value equal
 263                  to LAST, and prints differently from the previous
 264                  number, then print the number.  This avoids problems
 265                  with rounding.  For example, with the x86 it causes
 266                  "seq 0 0.000001 0.000003" to print 0.000003 instead
 267                  of stopping at 0.000002.  */
 268
 269               bool print_extra_number = false;
 270               long double x_val;
 271               char *x_str;
 272               int x_strlen;
 273               setlocale (LC_NUMERIC, "C");
 274               x_strlen = asprintf (&x_str, fmt, x);
 275               setlocale (LC_NUMERIC, "");
 276               if (x_strlen < 0)
 277                 xalloc_die ();
 278               x_str[x_strlen - layout.suffix_len] = '\0';
 279
 280               if (xstrtold (x_str + layout.prefix_len, NULL, &x_val, c_strtold)
 281                   && x_val == last)
 282                 {
 283                   char *x0_str = NULL;
 284                   if (asprintf (&x0_str, fmt, x0) < 0)
 285                     xalloc_die ();
 286                   print_extra_number = !STREQ (x0_str, x_str);
 287                   free (x0_str);
 288                 }
 289
 290               free (x_str);
 291               if (! print_extra_number)
 292                 break;
 293             }
 294
 295           fputs (separator, stdout);
 296         }
 297
 298       fputs (terminator, stdout);
 299     }
 300 }
 301
 302 /* Return the default format given FIRST, STEP, and LAST.  */
 303 static char const *
 304 get_default_format (operand first, operand step, operand last)
 305 {
 306   static char format_buf[sizeof "%0.Lf" + 2 * INT_STRLEN_BOUND (int)];
 307
 308   int prec = MAX (first.precision, step.precision);
 309
 310   if (prec != INT_MAX && last.precision != INT_MAX)
 311     {
 312       if (equal_width)
 313         {
 314           /* increase first_width by any increased precision in step */
 315           size_t first_width = first.width + (prec - first.precision);
 316           /* adjust last_width to use precision from first/step */
 317           size_t last_width = last.width + (prec - last.precision);
 318           if (last.precision && prec == 0)
 319             last_width--;  /* don't include space for '.' */
 320           size_t width = MAX (first_width, last_width);
 321           if (width <= INT_MAX)
 322             {
 323               int w = width;
 324               sprintf (format_buf, "%%0%d.%dLf", w, prec);
 325               return format_buf;
 326             }
 327         }
 328       else
 329         {
 330           sprintf (format_buf, "%%.%dLf", prec);
 331           return format_buf;
 332         }
 333     }
 334
 335   return "%Lg";
 336 }
 337
 338 int
 339 main (int argc, char **argv)
 340 {
 341   int optc;
 342   operand first = { 1, 1, 0 };
 343   operand step = { 1, 1, 0 };
 344   operand last;
 345   struct layout layout = { 0, 0 };
 346
 347   /* The printf(3) format used for output.  */
 348   char const *format_str = NULL;
 349
 350   initialize_main (&argc, &argv);
 351   set_program_name (argv[0]);
 352   setlocale (LC_ALL, "");
 353   bindtextdomain (PACKAGE, LOCALEDIR);
 354   textdomain (PACKAGE);
 355
 356   atexit (close_stdout);
 357
 358   equal_width = false;
 359   separator = "\n";
 360
 361   /* We have to handle negative numbers in the command line but this
 362      conflicts with the command line arguments.  So explicitly check first
 363      whether the next argument looks like a negative number.  */
 364   while (optind < argc)
 365     {
 366       if (argv[optind][0] == '-'
 367           && ((optc = argv[optind][1]) == '.' || ISDIGIT (optc)))
 368         {
 369           /* means negative number */
 370           break;
 371         }
 372
 373       optc = getopt_long (argc, argv, "+f:s:w", long_options, NULL);
 374       if (optc == -1)
 375         break;
 376
 377       switch (optc)
 378         {
 379         case 'f':
 380           format_str = optarg;
 381           break;
 382
 383         case 's':
 384           separator = optarg;
 385           break;
 386
 387         case 'w':
 388           equal_width = true;
 389           break;
 390
 391         case_GETOPT_HELP_CHAR;
 392
 393         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 394
 395         default:
 396           usage (EXIT_FAILURE);
 397         }
 398     }
 399
 400   if (argc - optind < 1)
 401     {
 402       error (0, 0, _("missing operand"));
 403       usage (EXIT_FAILURE);
 404     }
 405
 406   if (3 < argc - optind)
 407     {
 408       error (0, 0, _("extra operand %s"), quote (argv[optind + 3]));
 409       usage (EXIT_FAILURE);
 410     }
 411
 412   if (format_str)
 413     format_str = long_double_format (format_str, &layout);
 414
 415   last = scan_arg (argv[optind++]);
 416
 417   if (optind < argc)
 418     {
 419       first = last;
 420       last = scan_arg (argv[optind++]);
 421
 422       if (optind < argc)
 423         {
 424           step = last;
 425           last = scan_arg (argv[optind++]);
 426         }
 427     }
 428
 429   if (format_str != NULL && equal_width)
 430     {
 431       error (0, 0, _("\
 432 format string may not be specified when printing equal width strings"));
 433       usage (EXIT_FAILURE);
 434     }
 435
 436   if (format_str == NULL)
 437     format_str = get_default_format (first, step, last);
 438
 439   print_numbers (format_str, layout, first.value, step.value, last.value);
 440
 441   exit (EXIT_SUCCESS);
 442 }