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 <errno.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37
38 int opterr = 1, /* if error message should be printed */
39 optind = 1, /* index into parent argv vector */
40 optopt, /* character checked for validity */
41 optreset; /* reset getopt */
42 char *optarg; /* argument associated with option */
43
44 #define BADCH (int)'?'
45 #define BADARG (int)':'
46 #define EMSG ""
47
48 /*
49 * getopt --
50 * Parse argc/argv argument vector.
51 */
52 int
getopt(int nargc,char * const nargv[],const char * ostr)53 getopt(int nargc, char * const nargv[], const char *ostr)
54 {
55 static const char *place = EMSG; /* option letter processing */
56 char *oli; /* option letter list index */
57
58 if (optreset || *place == 0) { /* update scanning pointer */
59 optreset = 0;
60 place = nargv[optind];
61 if (optind >= nargc || *place++ != '-') {
62 /* Argument is absent or is not an option */
63 place = EMSG;
64 return (-1);
65 }
66 optopt = *place++;
67 if (optopt == '-' && *place == 0) {
68 /* "--" => end of options */
69 ++optind;
70 place = EMSG;
71 return (-1);
72 }
73 if (optopt == 0) {
74 /* Solitary '-', treat as a '-' option
75 if the program (eg su) is looking for it. */
76 place = EMSG;
77 if (strchr(ostr, '-') == NULL)
78 return -1;
79 optopt = '-';
80 }
81 } else
82 optopt = *place++;
83
84 /* See if option letter is one the caller wanted... */
85 if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
86 if (*place == 0)
87 ++optind;
88 if (opterr && *ostr != ':')
89 (void)fprintf(stderr,
90 "%s: unknown option -- %c\n", nargv[0],
91 optopt);
92 return (BADCH);
93 }
94
95 /* Does this option need an argument? */
96 if (oli[1] != ':') {
97 /* don't need argument */
98 optarg = NULL;
99 if (*place == 0)
100 ++optind;
101 } else {
102 /* Option-argument is either the rest of this argument or the
103 entire next argument. */
104 if (*place)
105 optarg = (char *)place;
106 else if (oli[2] == ':')
107 /*
108 * GNU Extension, for optional arguments if the rest of
109 * the argument is empty, we return NULL
110 */
111 optarg = NULL;
112 else if (nargc > ++optind)
113 optarg = nargv[optind];
114 else {
115 /* option-argument absent */
116 place = EMSG;
117 if (*ostr == ':')
118 return (BADARG);
119 if (opterr)
120 (void)fprintf(stderr,
121 "%s: option requires an argument -- %c\n",
122 nargv[0], optopt);
123 return (BADCH);
124 }
125 place = EMSG;
126 ++optind;
127 }
128 return (optopt); /* return option letter */
129 }
130