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 
51 int   opterr = 1,     /* if error message should be printed */
52       optind = 1;     /* index into parent argv vector */
53 int   optopt = 0;     /* character checked for validity */
54 static int optreset;  /* reset getopt */
55 char  *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  */
65 int
ares_getopt(int nargc,char * const nargv[],const char * ostr)66 ares_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