From Ulrich Drepper.

src/seq.c

@@ -0,0 +1,421 @@
+/* seq - print sequence of numbers to standard output.
+   Copyright (C) 1994 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Ulrich Drepper */
+
+#include <ctype.h>
+#include <getopt.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "version.h"
+
+static void usage ();
+static double scan_double_arg ();
+static int check_format ();
+static char *get_width_format ();
+static int print_numbers ();
+
+/* If non-zero print all number with equal width. */
+static int equal_width;
+
+/* The printf(3) format used for output. */
+static char *format_str;
+
+/* The starting number. */
+static double from;
+
+/* The name that this program was run with. */
+char *program_name;
+
+/* The string used to seperate two number. */
+static char *seperator;
+
+/* If non-zero, display usage information and exit.  */
+static int show_help;
+
+/* If non-zero, print the version on standard output and exit.  */
+static int show_version;
+
+/* The increment. */
+static double step;
+
+/* The last number. */
+static double last;
+
+static struct option const long_options[] =
+{
+  {
+    "equal-width", no_argument, NULL, 'w'
+  },
+  {
+    "format", required_argument, NULL, 'f'
+  },
+  {
+    "help", no_argument, &show_help, 1
+  },
+  {
+    "seperator", required_argument, NULL, 's'
+  },
+  {
+    "version", no_argument, &show_version, 1
+  },
+  {
+    NULL, 0, NULL, 0
+  }
+};
+
+static void
+usage (status)
+     int status;
+{
+  if (status != 0)
+    (void) fprintf (stderr, "Try `%s --help' for more information.\n",
+		    program_name);
+  else
+    {
+      (void) printf ("\
+Usage: %s [OPTION]... [from [step]] to\n\
+", program_name);
+      (void) printf ("\
+\n\
+  -f, --format FORMAT      use printf(3) style FORMAT (default: %%g)\n\
+      --help               display this help and exit\n\
+  -s, --seperator STRING   use STRING for seperating numbers (default: \\n)\n\
+      --version            output version information and exit\n\
+  -w, --equal-width        equalize width by padding with leading zeroes\n\
+\n\
+  FROM, STEP, TO are interpreted as floating point.  STEP has to be > 0 if\n\
+  FROM is bigger than TO and vice versa.  When given the FORMAT argument\n\
+  of the -f option has to contain exactly one of the float output formats\n\
+  %%e, %%f, or %%g.\n\
+");
+    }
+  exit (status);
+}
+
+void
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int errs;
+  int optc;
+  int step_is_set;
+
+  program_name = argv[0];
+  equal_width = 0;
+  format_str = NULL;
+  seperator = "\n";
+  from = 1.0;
+  step_is_set = 0;
+
+  /* We have to handle negative numbers in the command line but this 
+     conflicts with the command line arguments.  So the getopt mode is
+     REQUIRE_ORDER (the '+' in the format string) and it abort on the
+     first non-option or negative number.  */
+  while ((optc = getopt_long (argc, argv, "+0123456789f:s:w", long_options,
+			      (int *) 0)) != EOF)
+    {
+      if ('0' <= optc && optc <= '9')
+	{
+	  /* means negative number */
+	  break;
+	}
+
+      switch (optc)
+	{
+	case 0:
+	  break;
+
+	case 'f':
+	  format_str = optarg;
+	  break;
+
+	case 's':
+	  seperator = optarg;
+	  break;
+
+	case 'w':
+	  equal_width = 1;
+	  break;
+
+	default:
+	  usage (1);
+	  /* NOTREACHED */
+	}
+    }
+
+  if (show_version)
+    {
+      (void) printf ("seq - %s\n", version_string);
+    }
+
+  if (show_help)
+    {
+      usage (0);
+      /* NOTREACHED */
+    }
+
+  if (optind >= argc)
+    {
+      usage (2);
+      /* NOTREACHED */
+    }
+  last = scan_double_arg (argv[optind++]);
+
+  if (optind < argc)
+    {
+      from = last;
+      last = scan_double_arg (argv[optind++]);
+
+      if (optind < argc)
+	{
+	  step = last;
+	  step_is_set = 1;
+	  last = scan_double_arg (argv[optind++]);
+
+	  if (optind < argc)
+	    {
+	      usage (2);
+	      /* NOTREACHED */
+	    }
+	}
+    }
+
+  if (!step_is_set)
+    {
+      step = from < last ? 1.0 : -1.0;
+    }
+
+  if (format_str != NULL)
+    {
+      if (!check_format (format_str))
+	{
+	  fprintf (stderr, "illegal format string\n");
+	  usage (4);
+	}
+    }
+  else
+    {
+      if (equal_width)
+	format_str = get_width_format ();
+      else
+	format_str = "%g";
+    }
+
+  errs = print_numbers (format_str);
+
+  exit (errs);
+  /* NOTREACHED */
+}
+
+/* Read an double value from the command line.
+   Return if the string is correct else signal error.  */
+
+static double
+scan_double_arg (arg)
+     char *arg;
+{
+  char *end_ptr;
+  double ret_val;
+
+  ret_val = strtod (arg, &end_ptr);
+  if (end_ptr == arg || *end_ptr != '\0')
+    {
+      fprintf (stderr, "illegal float argument: %s\n", arg);
+      usage (2);
+      /* NOTREACHED */
+    }
+
+  return ret_val;
+}
+
+/* Check whether the format string is valid for a single double
+   argument.
+   Return 0 if not, 1 if correct.  */
+
+static int
+check_format (format_string)
+     char *format_string;
+{
+  while (*format_string != '\0')
+    {
+      if (*format_string == '%')
+	{
+	  format_string++;
+	  if (*format_string != '%')
+	    break;
+	}
+
+      format_string++;
+    }
+  if (*format_string == '\0')
+    return 0;
+
+  format_string += strspn (format_string, "-+#0");
+  if (isdigit (*format_string))
+    {
+      format_string += strspn (format_string, "012345789");
+
+      if (*format_string == '.')
+	format_string += strspn (++format_string, "0123456789");
+    }
+
+  if (*format_string != 'e' && *format_string != 'f' &&
+      *format_string != 'g')
+    return 0;
+
+  format_string++;
+  while (*format_string != '\0')
+    {
+      if (*format_string == '%')
+	{
+	  format_string++;
+	  if (*format_string != '%')
+	    return 0;
+	}
+
+      format_string++;
+    }
+
+  return 1;
+}
+
+/* Returns the format for that all printed numbers have the same width.  */
+static char *
+get_width_format ()
+{
+  static char buffer[256];
+  int full_width;
+  int frac_width;
+  int width1, width2;
+  double max_val;
+  double min_val;
+  double temp;
+
+  if (from > last)
+    {
+      min_val = from - step * floor ((from - last) / step);
+      max_val = from;
+    }
+  else
+    {
+      min_val = from;
+      max_val = from + step * floor ((last - from) / step);
+    }
+
+  (void) sprintf (buffer, "%g", rint (max_val));
+  if (buffer[strspn (buffer, "0123456789")] != '\0')
+    return "%g";
+  width1 = strlen (buffer);
+
+  if (min_val < 0.0)
+    {
+      (void) sprintf (buffer, "%g", rint (min_val));
+      if (buffer[strspn (buffer, "-0123456789")] != '\0')
+	return "%g";
+      width2 = strlen (buffer);
+
+      width1 = width1 > width2 ? width1 : width2;
+    }
+  full_width = width1;
+
+  (void) sprintf (buffer, "%g", 1.0 + modf (min_val, &temp));
+  width1 = strlen (buffer);
+  if (width1 == 1)
+    width1 = 0;
+  else
+    {
+      if (buffer[0] != '1' || buffer[1] != '.' ||
+	  buffer[2 + strspn (&buffer[2], "0123456789")] != '\0')
+	return "%g";
+      width1 -= 2;
+    }
+
+  (void) sprintf (buffer, "%g", 1.0 + modf (step, &temp));
+  width2 = strlen (buffer);
+  if (width2 == 1)
+    width2 = 0;
+  else
+    {
+      if (buffer[0] != '1' || buffer[1] != '.' ||
+	  buffer[2 + strspn (&buffer[2], "0123456789")] != '\0')
+	return "%g";
+      width2 -= 2;
+    }
+  frac_width = width1 > width2 ? width1 : width2;
+
+  if (frac_width)
+    (void) sprintf (buffer, "%%0%d.%df", full_width + 1 + frac_width, frac_width);
+  else
+    (void) sprintf (buffer, "%%0%dg", full_width);
+
+  return buffer;
+}
+
+/* Actually print the sequence of numbers in the specified range, with the
+   given or default stepping and format.  */
+static int
+print_numbers (format_str)
+     char *format_str;
+{
+  if (from > last)
+    {
+      if (step >= 0)
+	{
+	  (void) fprintf (stderr, "illegal increment: %g\n", step);
+	  usage (2);
+	  /* NOTREACHED */
+	}
+
+      while (1)
+	{
+	  (void) printf (format_str, from);
+
+	  from += step;
+	  if (from < last)
+	    break;
+
+	  (void) fputs (seperator, stdout);
+	}
+    }
+  else
+    {
+      if (step <= 0)
+	{
+	  (void) fprintf (stderr, "illegal increment: %g\n", step);
+	  usage (2);
+	  /* NOTREACHED */
+	}
+
+      while (1)
+	{
+	  (void) printf (format_str, from);
+
+	  from += step;
+	  if (from > last)
+	    break;
+
+	  (void) fputs (seperator, stdout);
+	}
+    }
+
+  return 0;
+}