1 /* seq - print sequence of numbers to standard output.
2 Copyright (C) 1994-2008 Free Software Foundation, Inc.
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.
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.
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/>. */
17 /* Written by Ulrich Drepper. */
22 #include <sys/types.h>
32 /* Roll our own isfinite rather than using <math.h>, so that we don't
33 have to worry about linking -lm just for isfinite. */
35 # define isfinite(x) ((x) * 0 == 0)
38 /* The official name of this program (e.g., no `g' prefix). */
39 #define PROGRAM_NAME "seq"
41 #define AUTHORS proper_name ("Ulrich Drepper")
43 /* If true print all number with equal width. */
44 static bool equal_width;
46 /* The string used to separate two numbers. */
47 static char const *separator;
49 /* The string output after all numbers have been output.
50 Usually "\n" or "\0". */
51 /* FIXME: make this an option. */
52 static char const terminator[] = "\n";
54 static struct option const long_options[] =
56 { "equal-width", no_argument, NULL, 'w'},
57 { "format", required_argument, NULL, 'f'},
58 { "separator", required_argument, NULL, 's'},
59 {GETOPT_HELP_OPTION_DECL},
60 {GETOPT_VERSION_OPTION_DECL},
67 if (status != EXIT_SUCCESS)
68 fprintf (stderr, _("Try `%s --help' for more information.\n"),
73 Usage: %s [OPTION]... LAST\n\
74 or: %s [OPTION]... FIRST LAST\n\
75 or: %s [OPTION]... FIRST INCREMENT LAST\n\
76 "), program_name, program_name, program_name);
78 Print numbers from FIRST to LAST, in steps of INCREMENT.\n\
80 -f, --format=FORMAT use printf style floating-point FORMAT\n\
81 -s, --separator=STRING use STRING to separate numbers (default: \\n)\n\
82 -w, --equal-width equalize width by padding with leading zeroes\n\
84 fputs (HELP_OPTION_DESCRIPTION, stdout);
85 fputs (VERSION_OPTION_DESCRIPTION, stdout);
88 If FIRST or INCREMENT is omitted, it defaults to 1. That is, an\n\
89 omitted INCREMENT defaults to 1 even when LAST is smaller than FIRST.\n\
90 FIRST, INCREMENT, and LAST are interpreted as floating point values.\n\
91 INCREMENT is usually positive if FIRST is smaller than LAST, and\n\
92 INCREMENT is usually negative if FIRST is greater than LAST.\n\
95 FORMAT must be suitable for printing one argument of type `double';\n\
96 it defaults to %.PRECf if FIRST, INCREMENT, and LAST are all fixed point\n\
97 decimal numbers with maximum precision PREC, and to %g otherwise.\n\
99 emit_bug_reporting_address ();
104 /* A command-line operand. */
107 /* Its value, converted to 'long double'. */
110 /* Its print width, if it were printed out in a form similar to its
111 input form. An input like "-.1" is treated like "-0.1", and an
112 input like "1." is treated like "1", but otherwise widths are
116 /* Number of digits after the decimal point, or INT_MAX if the
117 number can't easily be expressed as a fixed-point number. */
120 typedef struct operand operand;
122 /* Description of what a number-generating format will generate. */
125 /* Number of bytes before and after the number. */
130 /* Read a long double value from the command line.
131 Return if the string is correct else signal error. */
134 scan_arg (const char *arg)
138 if (! xstrtold (arg, NULL, &ret.value, c_strtold))
140 error (0, 0, _("invalid floating point argument: %s"), arg);
141 usage (EXIT_FAILURE);
144 /* We don't output spaces or '+' so don't include in width */
145 while (isspace (to_uchar (*arg)) || *arg == '+')
148 ret.width = strlen (arg);
149 ret.precision = INT_MAX;
151 if (! arg[strcspn (arg, "xX")] && isfinite (ret.value))
153 char const *decimal_point = strchr (arg, '.');
158 size_t fraction_len = strcspn (decimal_point + 1, "eE");
159 if (fraction_len <= INT_MAX)
160 ret.precision = fraction_len;
161 ret.width += (fraction_len == 0 /* #. -> # */
163 : (decimal_point == arg /* .# -> 0.# */
164 || ! ISDIGIT (decimal_point[-1]))); /* -.# -> 0.# */
166 char const *e = strchr (arg, 'e');
168 e = strchr (arg, 'E');
171 long exponent = strtol (e + 1, NULL, 10);
172 ret.precision += exponent < 0 ? -exponent : 0;
179 /* Validate the format, FMT. Print a diagnostic and exit
180 if there is not exactly one %-directive. */
183 validate_format (char const *fmt)
185 unsigned int n_directives = 0;
188 for (p = fmt; *p; p++)
190 if (p[0] == '%' && p[1] != '%' && p[1] != '\0')
196 if (n_directives == 0)
198 error (0, 0, _("no %% directive in format string %s"), quote (fmt));
199 usage (EXIT_FAILURE);
201 else if (1 < n_directives)
202 error (EXIT_FAILURE, 0, _("too many %% directives in format string %s"),
206 /* If FORMAT is a valid printf format for a double argument, return
207 its long double equivalent, possibly allocated from dynamic
208 storage, and store into *LAYOUT a description of the output layout;
209 otherwise, return NULL. */
212 long_double_format (char const *fmt, struct layout *layout)
215 size_t prefix_len = 0;
216 size_t suffix_len = 0;
217 size_t length_modifier_offset;
220 for (i = 0; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
227 i += strspn (fmt + i, "-+#0 '");
228 i += strspn (fmt + i, "0123456789");
232 i += strspn (fmt + i, "0123456789");
235 length_modifier_offset = i;
236 has_L = (fmt[i] == 'L');
238 /* In a valid format string, fmt[i] must be one of these specifiers. */
239 if (fmt[i] == '\0' || ! strchr ("efgaEFGA", fmt[i]))
242 for (i++; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
247 size_t format_size = i + 1;
248 char *ldfmt = xmalloc (format_size + 1);
249 memcpy (ldfmt, fmt, length_modifier_offset);
250 ldfmt[length_modifier_offset] = 'L';
251 strcpy (ldfmt + length_modifier_offset + 1,
252 fmt + length_modifier_offset + has_L);
253 layout->prefix_len = prefix_len;
254 layout->suffix_len = suffix_len;
261 /* Return the absolute relative difference from x to y. */
263 abs_rel_diff (double x, double y)
265 double s = (y == 0.0 ? 1 : y);
266 return fabs ((y - x) / s);
269 /* Actually print the sequence of numbers in the specified range, with the
270 given or default stepping and format. */
273 print_numbers (char const *fmt, struct layout layout,
274 long double first, long double step, long double last)
276 bool out_of_range = (step < 0 ? first < last : last < first);
280 long double x = first;
289 x = first + i * step;
290 out_of_range = (step < 0 ? x < last : last < x);
294 /* If the number just past LAST prints as a value equal
295 to LAST, and prints differently from the previous
296 number, then print the number. This avoids problems
297 with rounding. For example, with the x86 it causes
298 "seq 0 0.000001 0.000003" to print 0.000003 instead
299 of stopping at 0.000002. */
301 bool print_extra_number = false;
304 int x_strlen = asprintf (&x_str, fmt, x);
307 x_str[x_strlen - layout.suffix_len] = '\0';
309 if (xstrtold (x_str + layout.prefix_len, NULL, &x_val, c_strtold)
310 && abs_rel_diff (x_val, last) < DBL_EPSILON)
313 if (asprintf (&x0_str, fmt, x0) < 0)
315 print_extra_number = !STREQ (x0_str, x_str);
320 if (! print_extra_number)
324 fputs (separator, stdout);
327 fputs (terminator, stdout);
331 /* Return the default format given FIRST, STEP, and LAST. */
333 get_default_format (operand first, operand step, operand last)
335 static char format_buf[sizeof "%0.Lf" + 2 * INT_STRLEN_BOUND (int)];
337 int prec = MAX (first.precision, step.precision);
339 if (prec != INT_MAX && last.precision != INT_MAX)
343 /* increase first_width by any increased precision in step */
344 size_t first_width = first.width + (prec - first.precision);
345 /* adjust last_width to use precision from first/step */
346 size_t last_width = last.width + (prec - last.precision);
347 if (last.precision && prec == 0)
348 last_width--; /* don't include space for '.' */
349 size_t width = MAX (first_width, last_width);
350 if (width <= INT_MAX)
353 sprintf (format_buf, "%%0%d.%dLf", w, prec);
359 sprintf (format_buf, "%%.%dLf", prec);
368 main (int argc, char **argv)
371 operand first = { 1, 1, 0 };
372 operand step = { 1, 1, 0 };
374 struct layout layout = { 0, 0 };
376 /* The printf(3) format used for output. */
377 char const *format_str = NULL;
379 initialize_main (&argc, &argv);
380 set_program_name (argv[0]);
381 setlocale (LC_ALL, "");
382 bindtextdomain (PACKAGE, LOCALEDIR);
383 textdomain (PACKAGE);
385 atexit (close_stdout);
390 /* We have to handle negative numbers in the command line but this
391 conflicts with the command line arguments. So explicitly check first
392 whether the next argument looks like a negative number. */
393 while (optind < argc)
395 if (argv[optind][0] == '-'
396 && ((optc = argv[optind][1]) == '.' || ISDIGIT (optc)))
398 /* means negative number */
402 optc = getopt_long (argc, argv, "+f:s:w", long_options, NULL);
420 case_GETOPT_HELP_CHAR;
422 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
425 usage (EXIT_FAILURE);
429 if (argc - optind < 1)
431 error (0, 0, _("missing operand"));
432 usage (EXIT_FAILURE);
435 if (3 < argc - optind)
437 error (0, 0, _("extra operand %s"), quote (argv[optind + 3]));
438 usage (EXIT_FAILURE);
443 validate_format (format_str);
444 char const *f = long_double_format (format_str, &layout);
447 error (0, 0, _("invalid format string: %s"), quote (format_str));
448 usage (EXIT_FAILURE);
453 last = scan_arg (argv[optind++]);
458 last = scan_arg (argv[optind++]);
463 last = scan_arg (argv[optind++]);
467 if (format_str != NULL && equal_width)
470 format string may not be specified when printing equal width strings"));
471 usage (EXIT_FAILURE);
474 if (format_str == NULL)
475 format_str = get_default_format (first, step, last);
477 print_numbers (format_str, layout, first.value, step.value, last.value);