1 /* $NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 christos Exp $ */
2
3 /*
4 * Copyright (c) 1987, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 christos Exp $");
34
35 #include "namespace.h"
36
37 #include <assert.h>
38 #include <errno.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 #ifdef __weak_alias
45 __weak_alias(getopt,_getopt)
46 #endif
47
48 int opterr = 1, /* if error message should be printed */
49 optind = 1, /* index into parent argv vector */
50 optopt, /* character checked for validity */
51 optreset; /* reset getopt */
52 char *optarg; /* argument associated with option */
53
54 #define BADCH (int)'?'
55 #define BADARG (int)':'
56 #define EMSG ""
57
58 /*
59 * getopt --
60 * Parse argc/argv argument vector.
61 */
62 int
getopt(int nargc,char * const nargv[],const char * ostr)63 getopt(int nargc, char * const nargv[], const char *ostr)
64 {
65 static const char *place = EMSG; /* option letter processing */
66 char *oli; /* option letter list index */
67
68 _DIAGASSERT(nargv != NULL);
69 _DIAGASSERT(ostr != NULL);
70
71 if (optreset || *place == 0) { /* update scanning pointer */
72 optreset = 0;
73 place = nargv[optind];
74 if (optind >= nargc || *place++ != '-') {
75 /* Argument is absent or is not an option */
76 place = EMSG;
77 return (-1);
78 }
79 optopt = *place++;
80 if (optopt == '-' && *place == 0) {
81 /* "--" => end of options */
82 ++optind;
83 place = EMSG;
84 return (-1);
85 }
86 if (optopt == 0) {
87 /* Solitary '-', treat as a '-' option
88 if the program (eg su) is looking for it. */
89 place = EMSG;
90 if (strchr(ostr, '-') == NULL)
91 return -1;
92 optopt = '-';
93 }
94 } else
95 optopt = *place++;
96
97 /* See if option letter is one the caller wanted... */
98 if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
99 if (*place == 0)
100 ++optind;
101 if (opterr && *ostr != ':')
102 (void)fprintf(stderr,
103 "%s: unknown option -- %c\n", getprogname(),
104 optopt);
105 return (BADCH);
106 }
107
108 /* Does this option need an argument? */
109 if (oli[1] != ':') {
110 /* don't need argument */
111 optarg = NULL;
112 if (*place == 0)
113 ++optind;
114 } else {
115 /* Option-argument is either the rest of this argument or the
116 entire next argument. */
117 if (*place)
118 optarg = __UNCONST(place);
119 else if (oli[2] == ':')
120 /*
121 * GNU Extension, for optional arguments if the rest of
122 * the argument is empty, we return NULL
123 */
124 optarg = NULL;
125 else if (nargc > ++optind)
126 optarg = nargv[optind];
127 else {
128 /* option-argument absent */
129 place = EMSG;
130 if (*ostr == ':')
131 return (BADARG);
132 if (opterr)
133 (void)fprintf(stderr,
134 "%s: option requires an argument -- %c\n",
135 getprogname(), optopt);
136 return (BADCH);
137 }
138 place = EMSG;
139 ++optind;
140 }
141 return (optopt); /* return option letter */
142 }
143