1/*
2 * Original file name getopt.c  Initial import into the c-ares source tree
3 * on 2007-04-11.  Lifted from version 5.2 of the 'Open Mash' project with
4 * the modified BSD license, BSD license without the advertising clause.
5 *
6 */
7
8/*
9 * getopt.c --
10 *
11 *      Standard UNIX getopt function.  Code is from BSD.
12 *
13 * Copyright (c) 1987-2001 The Regents of the University of California.
14 * All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions are met:
18 *
19 * A. Redistributions of source code must retain the above copyright notice,
20 *    this list of conditions and the following disclaimer.
21 * B. Redistributions in binary form must reproduce the above copyright notice,
22 *    this list of conditions and the following disclaimer in the documentation
23 *    and/or other materials provided with the distribution.
24 * C. Neither the names of the copyright holders nor the names of its
25 *    contributors may be used to endorse or promote products derived from this
26 *    software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
29 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
30 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
32 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41/* #if !defined(lint)
42 * static char sccsid[] = "@(#)getopt.c 8.2 (Berkeley) 4/2/94";
43 * #endif
44 */
45
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include "ares_getopt.h"
50
51int   opterr = 1,     /* if error message should be printed */
52      optind = 1;     /* index into parent argv vector */
53int   optopt = 0;     /* character checked for validity */
54static int optreset;  /* reset getopt */
55char  *optarg;        /* argument associated with option */
56
57#define  BADCH   (int)'?'
58#define  BADARG  (int)':'
59#define  EMSG    (char *)""
60
61/*
62 * ares_getopt --
63 *    Parse argc/argv argument vector.
64 */
65int
66ares_getopt(int nargc, char * const nargv[], const char *ostr)
67{
68    static char *place = EMSG;                /* option letter processing */
69    char *oli;                                /* option letter list index */
70
71    if (optreset || !*place) {                /* update scanning pointer */
72        optreset = 0;
73        if (optind >= nargc || *(place = nargv[optind]) != '-') {
74            place = EMSG;
75            return (EOF);
76        }
77        if (place[1] && *++place == '-') {    /* found "--" */
78            ++optind;
79            place = EMSG;
80            return (EOF);
81        }
82    }                                         /* option letter okay? */
83    if ((optopt = (int)*place++) == (int)':' ||
84        (oli = strchr(ostr, optopt)) == NULL) {
85        /*
86         * if the user didn't specify '-' as an option,
87         * assume it means EOF.
88         */
89        if (optopt == (int)'-')
90            return (EOF);
91        if (!*place)
92            ++optind;
93        if (opterr && *ostr != ':')
94            (void)fprintf(stderr,
95                "%s: illegal option -- %c\n", __FILE__, optopt);
96        return (BADCH);
97    }
98    if (*++oli != ':') {                      /* don't need argument */
99        optarg = NULL;
100        if (!*place)
101            ++optind;
102    }
103    else {                                    /* need an argument */
104        if (*place)                           /* no white space */
105            optarg = place;
106        else if (nargc <= ++optind) {         /* no arg */
107            place = EMSG;
108            if (*ostr == ':')
109                return (BADARG);
110            if (opterr)
111                (void)fprintf(stderr,
112                    "%s: option requires an argument -- %c\n",
113                    __FILE__, optopt);
114            return (BADCH);
115        }
116         else                                 /* white space */
117            optarg = nargv[optind];
118        place = EMSG;
119        ++optind;
120    }
121    return (optopt);                          /* dump back option letter */
122}
123