ethstream/opt.c

/*
 * Copyright (c) 2003-2007 Jim Paris <jim@jtan.com>
 *
 * This is free software; you can redistribute it and/or modify it and
 * it is provided under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation; see COPYING.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "opt.h"

void
opt_init (int *optind)
{
  *optind = 0;
}

char
opt_parse (int argc, char **argv, int *optind, char **optarg,
	   struct options *opt)
{
  char c;
  int i;
  (*optind)++;
  if (*optind >= argc)
    return 0;

  if (argv[*optind][0] == '-' &&
      argv[*optind][1] != '-' && argv[*optind][1] != 0)
    {
      /* Short option (or a bunch of 'em) */
      /* Save this and shift others over */
      c = argv[*optind][1];
      for (i = 2; argv[*optind][i] != 0; i++)
	argv[*optind][i - 1] = argv[*optind][i];
      argv[*optind][i - 1] = 0;
      if (argv[*optind][1] != 0)
	(*optind)--;
      /* Now find it */
      for (i = 0; opt[i].shortopt != 0; i++)
	if (opt[i].shortopt == c)
	  break;
      if (opt[i].shortopt == 0)
	{
	  fprintf (stderr, "Error: unknown option '-%c'\n", c);
	  return '?';
	}
      if (opt[i].arg == NULL)
	return c;
      (*optind)++;
      if (*optind >= argc || (argv[*optind][0] == '-' &&
			      argv[*optind][1] != 0))
	{
	  fprintf (stderr, "Error: option '-%c' requires an "
		   "argument\n", c);
	  return '?';
	}
      (*optarg) = argv[*optind];
      return c;
    }
  else if (argv[*optind][0] == '-' &&
	   argv[*optind][1] == '-' && argv[*optind][2] != 0)
    {
      /* Long option */
      for (i = 0; (c = opt[i].shortopt) != 0; i++)
	if (strcmp (opt[i].longopt, argv[*optind] + 2) == 0)
	  break;
      if (opt[i].shortopt == 0)
	{
	  fprintf (stderr, "Error: unknown option '%s'\n", argv[*optind]);
	  return '?';
	}
      if (opt[i].arg == NULL)
	return c;
      (*optind)++;
      if (*optind >= argc || (argv[*optind][0] == '-' &&
			      argv[*optind][1] != 0))
	{
	  fprintf (stderr, "Error: option '%s' requires an "
		   "argument\n", argv[*optind - 1]);
	  return '?';
	}
      (*optarg) = argv[*optind];
      return c;
    }
  else
    {
      /* End of options */
      return 0;
    }
}

void
opt_help (struct options *opt, FILE * out)
{
  int i;
  int printed;

  for (i = 0; opt[i].shortopt != 0; i++)
    {
      fprintf (out, "  -%c, --%s%n", opt[i].shortopt,
	       opt[i].longopt, &printed);
      fprintf (out, " %-*s%s\n", 30 - printed,
	       opt[i].arg ? opt[i].arg : "", opt[i].help);
    }
}