/*
 * Copyright (c) 1987, 1993, 1994, 1995
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#ifndef __P
#define __P(x) x
#endif
#define _DIAGASSERT(x) assert(x)

#ifdef __weak_alias
__weak_alias(getopt, _getopt);
#endif

int opterr = 1, /* if error message should be printed */
    optind = 1, /* index into parent argv vector */
    optopt,     /* character checked for validity */
    optreset;   /* reset getopt */
char *optarg;   /* argument associated with option */

static char *_progname __P((char *));

int getopt_internal __P((int, char *const *, const char *));

static char *_progname(nargv0)

    char *nargv0;
{
  char *tmp;

  _DIAGASSERT(nargv0 != NULL);

  tmp = strrchr(nargv0, '/');
  if (tmp)
    tmp++;
  else
    tmp = nargv0;
  return (tmp);
}

#define BADCH (int)'?'
#define BADARG (int)':'
#define EMSG ""

/*
 * getopt --
 *	Parse argc/argv argument vector.
 */
int getopt(nargc, nargv, ostr)

    int nargc;
char *const nargv[];
const char *ostr;
{
  static char *__progname = 0;
  static char *place = EMSG; /* option letter processing */
  char *oli;                 /* option letter list index */
  __progname = __progname ? __progname : _progname(*nargv);

  _DIAGASSERT(nargv != NULL);
  _DIAGASSERT(ostr != NULL);

  if (optreset || !*place) { /* update scanning pointer */
    optreset = 0;
    if (optind >= nargc || *(place = nargv[optind]) != '-') {
      place = EMSG;
      return (-1);
    }
    if (place[1] && *++place == '-' /* found "--" */
        && place[1] == '\0') {
      ++optind;
      place = EMSG;
      return (-1);
    }
  } /* option letter okay? */
  if ((optopt = (int)*place++) == (int)':' || !(oli = strchr(ostr, optopt))) {
    /*
     * if the user didn't specify '-' as an option,
     * assume it means -1.
     */
    if (optopt == (int)'-')
      return (-1);
    if (!*place)
      ++optind;
    if (opterr && *ostr != ':')
      (void)fprintf(stderr, "%s: illegal option -- %c\n", __progname, optopt);
    return (BADCH);
  }
  if (*++oli != ':') { /* don't need argument */
    optarg = NULL;
    if (!*place)
      ++optind;
  } else {      /* need an argument */
    if (*place) /* no white space */
      optarg = place;
    else if (nargc <= ++optind) { /* no arg */
      place = EMSG;
      if (*ostr == ':')
        return (BADARG);
      if (opterr)
        (void)fprintf(stderr, "%s: option requires an argument -- %c\n",
                      __progname, optopt);
      return (BADCH);
    } else /* white space */
      optarg = nargv[optind];
    place = EMSG;
    ++optind;
  }
  return (optopt); /* dump back option letter */
}
