/*
 * Copyright (c) 1987, 1993
 *      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 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getopt.c    8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */

#ifndef __STDC__
#define const
#endif
#include <config.h>
#include "roken.h"

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

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

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

ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
getopt(int nargc, char * const *nargv, const char *ostr)
{
        static char *place = EMSG;              /* option letter processing */
        char *oli;                      /* option letter list index */
        char *p;

        if (optreset || !*place) {              /* update scanning pointer */
                optreset = 0;
                if (optind >= nargc || *(place = nargv[optind]) != '-') {
                        place = EMSG;
                        return(-1);
                }
                if (place[1] && *++place == '-') {      /* found "--" */
                        ++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 (EOF).
                 */
                if (optopt == (int)'-')
                        return(-1);
                if (!*place)
                        ++optind;
                if (opterr && *ostr != ':') {
                        if (!(p = strrchr(*nargv, '/')))
                                p = *nargv;
                        else
                                ++p;
                        fprintf(stderr, "%s: illegal option -- %c\n",
                            p, 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 (!(p = strrchr(*nargv, '/')))
                                p = *nargv;
                        else
                                ++p;
                        if (*ostr == ':')
                                return(BADARG);
                        if (opterr)
                                fprintf(stderr,
                                    "%s: option requires an argument -- %c\n",
                                    p, optopt);
                        return(BADCH);
                }
                else                            /* white space */
                        optarg = nargv[optind];
                place = EMSG;
                ++optind;
        }
        return(optopt);                         /* dump back option letter */
}