/*      $NetBSD: egetopt.c,v 1.9 2011/09/06 18:26:06 joerg Exp $        */

/*-
* Copyright (c) 1991 Keith Muller.
* Copyright (c) 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Keith Muller of the University of California, San Diego.
*
* 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 name of the University 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 REGENTS 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 <sys/cdefs.h>
#ifndef lint
#if 0
from: static char sccsid[] = "@(#)egetopt.c     8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: egetopt.c,v 1.9 2011/09/06 18:26:06 joerg Exp $");
#endif
#endif /* not lint */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "extern.h"

/*
* egetopt:     get option letter from argument vector (an extended
*              version of getopt).
*
* Non standard additions to the ostr specs are:
* 1) '?': immediate value following arg is optional (no white space
*    between the arg and the value)
* 2) '#': +/- followed by a number (with an optional sign but
*    no white space between the arg and the number). The - may be
*    combined with other options, but the + cannot.
*/

int     eopterr = 1;            /* if error message should be printed */
int     eoptind = 1;            /* index into parent argv vector */
int     eoptopt;                /* character checked for validity */
char    *eoptarg;               /* argument associated with option */

#define BADCH   (int)'?'
static char EMSG[1] = { '\0' };

int
egetopt(int nargc, char * const *nargv, const char *ostr)
{
       static char *place = EMSG;      /* option letter processing */
       char *oli;                      /* option letter list index */
       static int delim;               /* which option delimiter */
       char *p;
       static char savec = '\0';

       if (savec != '\0') {
               *place = savec;
               savec = '\0';
       }

       if (!*place) {
               /*
                * update scanning pointer
                */
               if ((eoptind >= nargc) ||
                   ((*(place = nargv[eoptind]) != '-') && (*place != '+'))) {
                       place = EMSG;
                       return (-1);
               }

               delim = (int)*place;
               if (place[1] && *++place == '-' && !place[1]) {
                       /*
                        * found "--"
                        */
                       ++eoptind;
                       place = EMSG;
                       return (-1);
               }
       }

       /*
        * check option letter
        */
       if ((eoptopt = (int)*place++) == (int)':' || (eoptopt == (int)'?') ||
           !(oli = strchr(ostr, eoptopt))) {
               /*
                * if the user didn't specify '-' as an option,
                * assume it means -1 when by itself.
                */
               if ((eoptopt == (int)'-') && !*place)
                       return (-1);
               if (strchr(ostr, '#') && (isdigit(eoptopt) ||
                   (((eoptopt == (int)'-') || (eoptopt == (int)'+')) &&
                     isdigit((unsigned char)*place)))) {
                       /*
                        * # option: +/- with a number is ok
                        */
                       for (p = place; *p != '\0'; ++p) {
                               if (!isdigit((unsigned char)*p))
                                       break;
                       }
                       eoptarg = place-1;

                       if (*p == '\0') {
                               place = EMSG;
                               ++eoptind;
                       } else {
                               place = p;
                               savec = *p;
                               *place = '\0';
                       }
                       return (delim);
               }

               if (!*place)
                       ++eoptind;
               if (eopterr) {
                       if (!(p = strrchr(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr, "%s: illegal option -- %c\n",
                           p, eoptopt);
               }
               return (BADCH);
       }
       if (delim == (int)'+') {
               /*
                * '+' is only allowed with numbers
                */
               if (!*place)
                       ++eoptind;
               if (eopterr) {
                       if (!(p = strrchr(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr,
                               "%s: illegal '+' delimiter with option -- %c\n",
                               p, eoptopt);
               }
               return (BADCH);
       }
       ++oli;
       if ((*oli != ':') && (*oli != '?')) {
               /*
                * don't need argument
                */
               eoptarg = NULL;
               if (!*place)
                       ++eoptind;
               return (eoptopt);
       }

       if (*place) {
               /*
                * no white space
                */
               eoptarg = place;
       } else if (*oli == '?') {
               /*
                * no arg, but NOT required
                */
               eoptarg = NULL;
       } else if (nargc <= ++eoptind) {
               /*
                * no arg, but IS required
                */
               place = EMSG;
               if (eopterr) {
                       if (!(p = strrchr(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr,
                           "%s: option requires an argument -- %c\n", p,
                           eoptopt);
               }
               return (BADCH);
       } else {
               /*
                * arg has white space
                */
               eoptarg = nargv[eoptind];
       }
       place = EMSG;
       ++eoptind;
       return (eoptopt);
}